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                                                                   EXHIBIT 10.15

                                      LEASE

                                 BY AND BETWEEN

                           MATHILDA ASSOCIATES II LLC,
                     A CALIFORNIA LIMITED LIABILITY COMPANY

                                   AS LANDLORD

                                       AND

                             JUNIPER NETWORKS, INC.,
                             A DELAWARE CORPORATION

                                    AS TENANT

                                 AUGUST 15, 2000

<PAGE>

                                      LEASE

      THIS LEASE, dated August 15, 2000 for reference purposes only, is made by
and between MATHILDA ASSOCIATES II LLC, a California limited liability company
("Landlord") and JUNIPER NETWORKS, INC., a Delaware corporation ("Tenant"), to
be effective and binding upon the parties as of the date the last of the
designated signatories to this Lease shall have executed this Lease (the
"Effective Date of this Lease").

                                    ARTICLE 1

                                    REFERENCE

1.1 REFERENCES. All references in this Lease (subject to any further
clarifications contained in this Lease) to the following terms shall have the
following meaning or refer to the respective address, person, date, time period,
amount, percentage, calendar year or fiscal year as below set forth:

<TABLE>
<S>                                 <C>
Tenant's Address for Notice:        1194 Mathilda Avenue
                                    Sunnyvale, California 94089

Tenant's Representative:            General Counsel

Landlord's Address for Notices:     c/o Menlo Equities LLC
                                    490 California Avenue, 4th Floor
                                    Palo Alto, California  94306

Landlord's Representative:          Henry Bullock/Richard Holmstrom
Phone Number:                       (650) 326-9300

Intended Delivery Date:             May 1, 2002

Intended Commencement Date:         June 1, 2002

Lease Term:                         Twelve (12) years

Lease Expiration Date:              Twelve (12) Years from the Lease Commencement Date, unless
                                    earlier terminated in accordance with the terms of this
                                    Lease, or extended by Tenant pursuant to Article 15.

Options to Renew:                   Two (2) option(s) to renew, each for a term of five (5)  years.

First Month's Prepaid Rent:         $404,095.65 (based on a projected rentable square footage of
                                    143,704) applied to the first month in which Base Monthly
                                    Rent is due)

Tenant's Security Deposit:          $1,000,000 (subject to adjustment pursuant to Paragraph 3.7)

Late Charge Amount:                 Five Percent (5%) of the Delinquent Amount

Tenant's Required Liability
Coverage:                           $3,000,000 Combined Single Limit

Tenant's Broker:                    None.

Landlord's Broker:                  None.

Property:                           That certain real property situated in the City of
                                    Sunnyvale, County of Santa Clara, State of California, to be
                                    improved with one building, which real property is shown on
                                    the Site Plan attached hereto as Exhibit "A".

Building:                           That certain building on the Property in which the Leased
                                    Premises are located commonly known as 1220 Mathilda Avenue
                                    (the "Building"), which Building is shown outlined on
                                    Exhibit "A" hereto (designated as Building C).

Outside Areas:                      The "Outside Areas" shall mean all areas which are located
                                    outside of and contiguous to the Building, as shown the Site
                                    Plan attached as Exhibit A, such as pedestrian walkways,
                                    parking areas, landscaped area, open areas and enclosed
                                    trash disposal areas.
</TABLE>

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<TABLE>
<S>                                 <C>
Leased Premises:                    All the interior space within the Building, including
                                    stairwells, connecting walkways, and atriums (as determined
                                    in accordance with Paragraph 2.5 below).

Tenant's Expense Share:             The term "Tenant's Expense Share" shall mean the percentage
                                    obtained by dividing the rentable square footage of the
                                    Leased Premises at the time of calculation by the rentable
                                    square footage of the Building. Such percentage is currently
                                    100%. In the event that the rentable square footage of the
                                    Leased Premises is changed, Tenant's Expense Share shall be
                                    recalculated to equal the percentage described in the first
                                    sentence of this paragraph, so that the aggregate Tenant's
                                    Expense Share of all tenants of the Building shall equal
                                    100%.

Tenant's Property Share:            The term "Tenant's Property Share" shall mean the percentage
                                    obtained by dividing the rentable square footage of the
                                    Leased Premises at the time of calculation by the rentable
                                    square footage of all buildings currently located or to be
                                    located on the Property. Such percentage is currently 100%.
                                    In the event that any portion of the Property is sold by
                                    Landlord, or the rentable square footage of the Leased
                                    Premises or the Property is otherwise changed, Tenant's
                                    Property Share shall be recalculated to equal the percentage
                                    described in the first sentence of this paragraph, so that
                                    the aggregate Tenant's Property Share of all tenants of the
                                    Property shall equal 100%.

Base Monthly Rent:                  The term "Base Monthly Rent" shall mean the following:

                                    Period         Base Monthly Rent per
                                                   Rentable Square Foot

                                    Months 1-12    $2.812

                                    Commencing with Month 13 of the Lease Term and at the end of
                                    each 12 month period thereafter (until the Lease Expiration
                                    Date), Base Monthly Rent shall be increased at a rate of
                                    3.5% per annum compounded annually.

Permitted Use:                      General Office, research and development, marketing, sales,
                                    manufacturing, distribution, warehouse and other related
                                    lawful uses.

Exhibits:                           The term "Exhibits" shall mean the Exhibits of this Lease
                                    which are described as follows:

                                    Exhibit "A" - Site Plan showing the Property, the Outside
                                    Areas and delineating the Building in which the Leased
                                    Premises are to be located.

                                    Exhibit "B" - Work Letter

                                    Exhibit "C" - Lease Commencement Date Certificate

                                    Exhibit "D" - Form of Tenant Estoppel Certificate

                                    Exhibit "E" - Form of Landlord Waiver
</TABLE>

                                   ARTICLE 2

                      LEASED PREMISES, TERM AND POSSESSION

2.1 DEMISE OF LEASED PREMISES. Landlord hereby leases to Tenant and Tenant
hereby leases from Landlord, for the Lease Term and upon the terms and subject
to the conditions of this Lease, that certain interior space described in
Article 1 as the Leased Premises, reserving and excepting to Landlord the right
to fifty percent (50%) of all assignment consideration and excess rentals as
provided in Article 7 below. Tenant's lease of the Leased Premises, together
with the appurtenant right to use the Outside Areas as described in Paragraph
2.2 below, shall be conditioned upon and be subject to the continuing compliance
by Tenant with (i) all the terms and conditions of this Lease, (ii) all Laws
governing the use of the Leased Premises and the Property, (iii) all Private
Restrictions, easements and other matters now of public record respecting the
use of the Leased Premises and Property, and (iv) all reasonable rules and
regulations from time to time established by Landlord.

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2.2 RIGHT TO USE OUTSIDE AREAS. As an appurtenant right to Tenant's right to the
use and occupancy of the Leased Premises, Tenant shall have the right to use the
Outside Areas in conjunction with its use of the Leased Premises solely for the
purposes for which they were designated and intended and for no other purposes
whatsoever. Tenant's right to so use the Outside Areas shall be subject to the
limitations on such use as set forth in Article 1 and shall terminate
concurrently with any termination of this Lease.

2.3 LEASE COMMENCEMENT DATE AND LEASE TERM. Subject to Paragraph 2.4 below, the
term of this Lease shall begin, and the Lease Commencement Date shall be deemed
to have occurred on the date which is thirty (30) days after the actual Delivery
Date, as determined pursuant to Section 2.4 below. The term of this Lease shall
in all events end on the Lease Expiration Date (as set forth in Article 1). The
Lease Term shall be that period of time commencing on the Lease Commencement
Date and ending on the Lease Expiration Date (the "Lease Term"). In the event
the actual Lease Commencement Date is different than the Intended Commencement
Date, Landlord and Tenant agree to execute a Lease Commencement Date Certificate
in the form attached as Exhibit C setting forth the actual Lease Commencement
Date and the Lease Expiration Date (such that the length of the Lease Term is
the same as set forth in Article 1) and an adjustment to the schedule of Base
Monthly Rent to reflect the change in the Lease Commencement Date and Lease
Expiration Date. The parties intend that this Lease shall be effective and
binding on the parties as of the Effective Date of the Lease; provided, however,
because Landlord does not currently own fee title to the Property, each of
Landlord's and Tenant's rights and obligations hereunder shall be conditioned
upon the close of escrow whereupon Landlord acquires fee title to the Property.

2.4 DELIVERY OF POSSESSION. Landlord shall deliver to Tenant possession of the
Leased Premises upon Substantial Completion of the Tenant Improvements as that
term is defined in the Work Letter attached hereto as Exhibit B. The date that
the Leased Premises are so delivered to the Tenant shall be deemed the "Delivery
Date." If Landlord is unable to so deliver possession of the Leased Premises to
Tenant in the agreed condition on or before the Intended Delivery Date, Landlord
shall have until the date that is thirty (30) days after the Intended Delivery
Date (the "Delivery Grace Period") to deliver the Leased Premises. Additionally,
the Delivery Grace Period above set forth shall be extended for such number of
days as Landlord may be delayed in delivering possession of the Leased Premises
to Tenant by reason of Force Majeure or the action or inaction of Tenant. If
Landlord is unable to deliver possession of the Leased Premises in the agreed
condition to Tenant within the Delivery Grace Period (including any extension
thereof by reason of Force Majeure or the actions or inactions of Tenant), then
Tenant shall receive as its sole remedy a credit of two (2) days of free rent
for each day that the Leased Premises are not delivered to Tenant after
expiration of the Delivery Grace Period (including any extension thereof by
reason of Force Majeure or the actions or inactions of Tenant), which free rent
shall apply to the first month in which Base Monthly Rent is due. If Landlord is
unable to deliver possession of the Leased Premises in the agreed condition to
Tenant within sixty (60) days after the expiration of the Delivery Grace Period
(including any extension thereof by reason of Force Majeure or the actions or
inactions of Tenant), Tenant may choose, as its sole remedy, to terminate this
Lease, and in the event of such termination Landlord shall not be liable in
damages to Tenant for any delay. Tenant may not terminate this Lease at any time
after the date Landlord notifies Tenant that the Leased Premises have been put
into the agreed condition and are available for delivery to Tenant, unless
Landlord's notice is not given in good faith. Tenant may occupy the Leased
Premises commencing on the Delivery Date for purposes of installing furniture,
fixtures and equipment, provided that Tenant shall be responsible for Additional
Rent during such period and Tenant shall comply with all other provisions of
this Lease (other than the payment of Base Monthly Rent).

2.5 PERFORMANCE OF TENANT IMPROVEMENTS; ACCEPTANCE OF POSSESSION. Landlord
shall, pursuant to the work letter attached to and made a part of this Lease
(the "Work Letter"), perform the work and make the installations in the Leased
Premises substantially as set forth in the Work Letter (such work and
installations hereinafter referred to as the "Tenant Improvements"). It is
agreed that by occupying the Leased Premises, Tenant formally accepts same and
acknowledges that the Leased Premises are in the condition called for hereunder,
subject to reasonable punchlist items and latent defects specified by Tenant to
Landlord in writing within ten (10) days of such occupancy. Upon completion of
the Base Building (as defined in the Work Letter), Landlord shall cause its
architect to measure the number of rentable square feet of the Leased Premises,
which shall be measured dripline to dripline. The Landlord's architect shall
present to both Landlord and Tenant in writing its determination of the number
of rentable square feet within the Leased Premises. Such number shall be binding
on Landlord and Tenant unless manifest error by Landlord's architect can be
demonstrated. The Lease Commencement Date Certificate shall reflect the number
of rentable square feet in the Leased Premises determined in accordance with the
foregoing.

2.6 SURRENDER OF POSSESSION. Immediately prior to the expiration or upon the
sooner termination of this Lease, Tenant shall remove all of Tenant's signs from
the exterior of the Building and shall remove all of Tenant's equipment, trade
fixtures, furniture, supplies, wall decorations and other personal property from
within the Leased Premises, the Building and the Outside Areas, and shall vacate
and surrender the Leased Premises, the Building, the Outside Areas and the
Property to Landlord in the same condition, broom clean, as existed at the Lease
Commencement Date, damage by casualty or condemnation (which events shall be
governed by Articles 10 and 11) and reasonable wear and tear excepted. Except
for such reasonable wear and tear, Tenant shall (i) repair all damage to the
Leased Premises, the exterior of the Building and the Outside Areas caused by
Tenant's removal of Tenant's property, (ii) patch and refinish, to Landlord's
reasonable satisfaction, all penetrations made by Tenant or its employees to the
roof, floor, interior or exterior walls or ceiling of the Leased Premises and
the Building, whether such penetrations were made with Landlord's approval or
not, (iii) repair or replace all stained or damaged ceiling tiles, wall
coverings and floor coverings to the reasonable satisfaction of Landlord, (iv)
repair all damage caused by Tenant to the exterior surface of the Building and
the paved surfaces of the Outside Areas and, where necessary, replace or
resurface same. Additionally, to the extent that Landlord shall have notified or
is deemed to have notified Tenant in writing at the time the improvements were
completed that it

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desired to have certain improvements made by Tenant or at the request of Tenant
removed at the expiration or sooner termination of the Lease, Tenant shall, upon
the expiration or sooner termination of the Lease, remove any such improvements
constructed or installed by Landlord or Tenant and repair all damage caused by
such removal; provided however, Tenant shall not be required to remove the
Tenant Improvements installed pursuant to the Work Letter. If the Leased
Premises, the Building, the Outside Areas and the Property are not surrendered
to Landlord in the condition required by this paragraph at the expiration or
sooner termination of this Lease, Landlord may, at Tenant's expense, so remove
Tenant's signs, property and/or improvements not so removed and make such
repairs and replacements not so made or hire, at Tenant's expense, independent
contractors to perform such work. Tenant shall be liable to Landlord for all
costs incurred by Landlord in returning the Leased Premises, the Building and
the Outside Areas to the required condition, together with interest on all costs
so incurred from the date paid by Landlord at the then maximum rate of interest
not prohibited or made usurious by law until paid. Tenant shall pay to Landlord
the amount of all costs so incurred plus such interest thereon, within ten (10)
days of Landlord's billing Tenant for same. Tenant shall indemnify Landlord
against loss or liability resulting from delay by Tenant in surrendering the
Leased Premises, including, without limitation, any claims made by any
succeeding Tenant or any losses to Landlord with respect to lost opportunities
to lease to succeeding tenants.

                                   ARTICLE 3

                    RENT, LATE CHARGES AND SECURITY DEPOSITS

3.1 BASE MONTHLY RENT. Commencing on the Lease Commencement Date (as determined
pursuant to Paragraph 2.3 above) and continuing throughout the Lease Term,
Tenant shall pay to Landlord, without prior demand therefor, in advance on the
first day of each calendar month, the amount set forth as "Base Monthly Rent" in
Article 1 (the "Base Monthly Rent").

3.2 ADDITIONAL RENT. Commencing on the Lease Commencement Date (as determined
pursuant to Paragraph 2.3 above) and continuing throughout the Lease Term, in
addition to the Base Monthly Rent and to the extent not required by Landlord to
be contracted for and paid directly by Tenant, Tenant shall pay to Landlord as
additional rent (the "Additional Rent") the following amounts:

      (a) An amount equal to all Property Operating Expenses (as defined in
Article 13) incurred by Landlord. Payment shall be made by whichever of the
following methods (or combination of methods) is (are) from time to time
designated by Landlord:

            (i) Landlord may forward invoices or bills for such expenses to
Tenant, and Tenant shall, no later than thirty (30) days following receipt of
any such invoices or bills, pay such invoices or bills and deliver satisfactory
evidence of such payment to Landlord, and/or

            (ii) Landlord may bill to Tenant, on a periodic basis not more
frequently than monthly, the amount of such expenses (or group of expenses) as
paid or incurred by Landlord, and Tenant shall pay to Landlord the amount of
such expenses within thirty (30) days after receipt of a written bill therefor
from Landlord, and/or

            (iii) Landlord may deliver to Tenant Landlord's reasonable estimate
of any given expense (such as Landlord's Insurance Costs or Real Property
Taxes), or group of expenses, which it anticipates will be paid or incurred for
the ensuing calendar or fiscal year, as Landlord may determine, and Tenant shall
pay to Landlord an amount equal to the estimated amount of such expenses for
such year in equal monthly installments during such year with the installments
of Base Monthly Rent.

Landlord reserves the right to change from time to time the methods of billing
Tenant for any given expense or group of expenses or the periodic basis on which
such expenses are billed.

      (b) Landlord's share of the consideration received by Tenant upon certain
assignments and sublettings as required by Article 7.

      (c) Any legal fees and costs that Tenant is obligated to pay or reimburse
to Landlord pursuant to Article 13; and

      (d) Any other charges or reimbursements due Landlord from Tenant pursuant
to the terms of this Lease.

Notwithstanding the foregoing, Landlord may elect by thirty (30) days prior
written notice to Tenant (provided such written notice is received by Tenant at
least thirty (30) days prior to delinquency) to have Tenant pay Real Property
Taxes or any portion thereof directly to the applicable taxing authority, in
which case Tenant shall make such payments and deliver satisfactory evidence of
payment to Landlord no later than ten (10) days before such Real Property Taxes
become delinquent.

Tenant may cause an audit of Landlord's books and records to determine the
accuracy of Landlord's billings for Property Operating Expenses under this
Lease, provided Tenant commences such audit within sixty (60) days after
Tenant's receipt of the year-end statement described in Section 3.3 above
setting forth the annual reconciliation of the Property Operating Expenses or
any change in estimated monthly expenses under Section 3.2(a)(iii) above. If
such audit reveals that the actual Property Operating Expenses for any given
year were less than the amount that Tenant paid for Property Operating Expenses
for any such year, then Landlord shall pay to Tenant the excess. If

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such audit reveals a discrepancy of more than three (3%) percent of the actual
amount of any Property Operating Expenses charges, then Landlord shall pay the
cost of the audit.

Additionally, Tenant shall have the right, by appropriate proceedings, to
protest or contest any assessment, reassessment or allocation of Real Property
Taxes or any change therein or any application of any Law to the Leased Premises
or Tenant's use thereof. Landlord will reasonably cooperate with Tenant in the
contest or proceedings. If Tenant does not pay the Real Property Taxes when due
which are the subject of such protest or contest, Tenant shall post a bond in
lieu thereof in an amount reasonably determined by Landlord but not less than
one hundred twenty-five percent (125%) of the amount demanded by the taxing
authorities which holds Landlord and the Property harmless from any damage
arising out of the contest and ensuring the payment of any judgment that may be
rendered. With respect to any contest of Real Property Taxes or Laws conducted
by Tenant, Tenant shall hold Landlord and the Property harmless from any damage
arising out of such protest or contest and shall pay any judgment that may be
rendered in connection with such contest or protest. Any protest or contest
conducted by Tenant under this paragraph shall be at Tenant's expense and if
interest or late charges become payable as a result of such contest or protest,
Tenant shall pay the same. Tenant shall receive a proportionate share of any
refund applicable to the Lease Term based on the amount of Real Property Taxes
paid by Tenant as Tenant's Property Share (if the refund is applicable to the
land) or Tenant's Expense Share (if the refund is applicable to the Building or
other improvements in the Outside Areas).

3.3 YEAR-END ADJUSTMENTS. If Landlord shall have elected to bill Tenant for the
Property Operating Expenses (or any group of such expenses) on an estimated
basis in accordance with the provisions of Paragraph 3.2(a)(iii) above, Landlord
shall furnish to Tenant within three months following the end of the applicable
calendar or fiscal year, as the case may be, a statement setting forth (i) the
amount of such expenses paid or incurred during the just ended calendar or
fiscal year, as appropriate, and (ii) the amount that Tenant has paid to
Landlord for credit against such expenses for such period. If Tenant shall have
paid more than its obligation for such expenses for the stated period, Landlord
shall, at its election, either (i) credit the amount of such overpayment toward
the next ensuing payment or payments of Additional Rent that would otherwise be
due or (ii) refund in cash to Tenant the amount of such overpayment within
thirty (30) days after it has been conclusively determined by Landlord that an
overpayment has been made by Tenant. If such year-end statement shall show that
Tenant did not pay its obligation for such expenses in full, then Tenant shall
pay to Landlord the amount of such underpayment within ten days from Landlord's
billing of same to Tenant. The provisions of this Paragraph shall survive the
expiration or sooner termination of this Lease.

3.4 LATE CHARGE, AND INTEREST ON RENT IN DEFAULT. Tenant acknowledges that the
late payment by Tenant of any monthly installment of Base Monthly Rent or any
Additional Rent will cause Landlord to incur certain costs and expenses not
contemplated under this Lease, the exact amounts of which are extremely
difficult or impractical to fix. Such costs and expenses will include without
limitation, administration and collection costs and processing and accounting
expenses. Therefor, if any installment of Base Monthly Rent is not received by
Landlord from Tenant when the same becomes due, Tenant shall immediately pay to
Landlord a late charge in an amount equal to the amount set forth in Article 1
as the "Late Charge Amount," and if any Additional Rent is not received by
Landlord when the same becomes due, Tenant shall immediately pay to Landlord a
late charge in an amount equal to 5% of the Additional Rent not so paid;
provided, however, that once but only once in any twelve (12) month period
during the Lease Term, Tenant shall be entitled to written notice of non-receipt
of Base Monthly Rent or Additional Rent from Landlord, and Tenant shall not be
liable for any Late Charge Amount or other late charge hereunder if such
installment of Base Monthly Rent or Additional Rent is received by Landlord
within ten (10) days after Tenant's receipt of such notice from Landlord.
Landlord and Tenant agree that this late charge represents a reasonable estimate
of such costs and expenses and is fair compensation to Landlord for the
anticipated loss Landlord would suffer by reason of Tenant's failure to make
timely payment. In no event shall this provision for a late charge be deemed to
grant to Tenant a grace period or extension of time within which to pay any
rental installment or prevent Landlord from exercising any right or remedy
available to Landlord upon Tenant's failure to pay each rental installment due
under this Lease when due, including the right to terminate this Lease. If any
rent remains delinquent for a period in excess of 10 calendar days, then, in
addition to such late charge, Tenant shall pay to Landlord interest on any rent
that is not so paid from said tenth day at the then maximum rate of interest not
prohibited or made usurious by Law until paid.

3.5 PAYMENT OF RENT. Except as specifically provided otherwise in this Lease,
all rent shall be paid in lawful money of the United States, without any
abatement, reduction or offset for any reason whatsoever, to Landlord at such
address as Landlord may designate from time to time. Tenant's obligation to pay
Base Monthly Rent and all Additional Rent shall be appropriately prorated at the
commencement and expiration of the Lease Term. The failure by Tenant to pay any
Additional Rent as required pursuant to this Lease when due shall be treated the
same as a failure by Tenant to pay Base Monthly Rent when due, and Landlord
shall have the same rights and remedies against Tenant as Landlord would have
had Tenant failed to pay the Base Monthly Rent when due.

3.6 PREPAID RENT. Tenant shall, within ten (10) days following execution of this
Lease, pay to Landlord the amount set forth in Article 1 as "First Month's
Prepaid Rent" as prepayment of rent for credit against the first payment of Base
Monthly Rent due hereunder.

3.7 SECURITY DEPOSIT. [intentionally deleted]

                                    ARTICLE 4

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                     USE OF LEASED PREMISES AND OUTSIDE AREA

4.1 PERMITTED USE. Tenant shall be entitled to use the Leased Premises solely
for the "Permitted Use" as set forth in Article 1 and for no other purpose
whatsoever. Tenant shall have the right to vacate the Leased Premises at any
time during the Term of this Lease, provided Tenant maintains the Leased
Premises in the same condition as if fully occupied and as otherwise required by
the terms of this Lease. Tenant shall have the right to use the Outside Areas in
conjunction with its Permitted Use of the Leased Premises solely for the
purposes for which they were designed and intended and for no other purposes
whatsoever.

4.2 GENERAL LIMITATIONS ON USE. Tenant shall not do or permit anything to be
done in or about the Leased Premises, the Building, the Outside Areas or the
Property which does or could (i) jeopardize the structural integrity of the
Building or (ii) cause damage to any part of the Leased Premises, the Building,
the Outside Areas or the Property. Tenant shall not operate any equipment within
the Leased Premises which does or could (i) injure, vibrate or shake the Leased
Premises or the Building, (ii) damage, overload or impair the efficient
operation of any electrical, plumbing, heating, ventilating or air conditioning
systems within or servicing the Leased Premises or the Building, or (iii) damage
or impair the efficient operation of the sprinkler system (if any) within or
servicing the Leased Premises or the Building. Tenant shall not (i) install any
equipment or antennas on or make any penetrations of the exterior walls or roof
of the Building or (ii) affix any equipment or make any penetrations or cuts in
the floors, ceiling or walls of the Leased Premises, without Landlord's prior
written consent, which consent shall not be unreasonably withheld; provided,
however, that it shall be reasonable for Landlord to withhold its consent if
Tenant's proposed installations or penetrations impact the structural integrity
of the Building. Any installations, penetrations or cuts in the interior or
exterior walls, roof, floor or ceiling of the Building will be subject to
Tenant's restoration obligations set forth in Section 2.6. Tenant shall not
place any loads upon the floors, walls, ceiling or roof systems which could
endanger the structural integrity of the Building or damage its floors,
foundations or supporting structural components. Tenant shall not place any
explosive, flammable or harmful fluids or other waste materials in the drainage
systems of the Leased Premises, the Building, the Outside Areas or the Property.
Tenant shall not drain or discharge any fluids in the landscaped areas or across
the paved areas of the Property. Tenant shall not use any of the Outside Areas
for the storage of its materials, supplies, inventory or equipment and all such
materials, supplies, inventory or equipment shall at all times be stored within
the Leased Premises. Tenant shall not commit nor permit to be committed any
waste in or about the Leased Premises, the Building, the Outside Areas or the
Property.

4.3 NOISE AND EMISSIONS. All noise generated by Tenant in its use of the Leased
Premises shall be confined or muffled so that it does not interfere with the
businesses of or annoy the occupants and/or users of adjacent properties. All
dust, fumes, odors and other emissions generated by Tenant's use of the Leased
Premises shall be sufficiently dissipated in accordance with sound environmental
practice and exhausted from the Leased Premises in such a manner so as not to
interfere with the businesses of or annoy the occupants and/or users of adjacent
properties, or cause any damage to the Leased Premises, the Building, the
Outside Areas or the Property or any component part thereof or the property of
adjacent property owners.

4.4 TRASH DISPOSAL. Tenant shall provide trash bins or other adequate garbage
disposal facilities within the trash enclosure areas provided or permitted by
Landlord outside the Leased Premises sufficient for the interim disposal of all
of its trash, garbage and waste. All such trash, garbage and waste temporarily
stored in such areas shall be stored in such a manner so that it is not visible
from outside of such areas, and Tenant shall cause such trash, garbage and waste
to be regularly removed from the Property. Tenant shall keep the Leased Premises
in a clean, safe and neat condition and keep the Outside Areas (except the trash
enclosure areas) free and clear of all of Tenant's trash, garbage, waste and/or
boxes, pallets and containers containing same at all times.

4.5 PARKING. Tenant shall have the use of the parking spaces located in the
Outside Areas (which, subject to any transportation management requirements of
the City of Sunnyvale, shall be no more than 3.2 spaces per 1,000 rentable
square feet in the Leased Premises). Tenant shall not, at any time, park or
permit to be parked any recreational vehicles, inoperative vehicles or equipment
in the Outside Areas or on any portion of the Property. Tenant agrees to assume
responsibility for compliance by its employees and invitees with the parking
provisions contained herein. If Tenant or its employees park any vehicle within
the Property in violation of these provisions, then Landlord may, upon prior
written notice to Tenant giving Tenant one (1) day (or any applicable statutory
notice period, if longer than one (1) day) to remove such vehicle(s). Landlord
reserves the right to grant easements and access rights to others for use of the
parking areas on the Property, provided that such grants do not materially
interfere with Tenant's use of the parking areas.

4.6 SIGNS. Other than business identification signs allowed pursuant to this
Section 4.6, Tenant shall not place or install on or within any portion of the
Leased Premises, the exterior of the Building, the Outside Areas or the Property
any sign, advertisement, banner, placard, or picture which is visible from the
exterior of the Leased Premises. Subject to Landlord's prior written consent,
which shall not be unreasonably withheld, and subject to approval by the City of
Sunnyvale, Tenant shall have the right to install an illuminated business
identification sign on the Building. Landlord shall cooperate with Tenant's
efforts to obtain approval from the City of Sunnyvale for an illuminated sign.
Any such sign shall be installed at Tenant's sole cost and expense and only in
strict compliance with Landlord's approval (which shall not be unreasonably
withheld), and all Laws and all requirements of the City of Sunnyvale, using a
person approved by Landlord to install same. Subject to Landlord's prior written
consent, which shall not be unreasonably withheld, and subject to approval by
the City of Sunnyvale of the installation of no less than two (2) monument signs
for the Property, Tenant shall have the right to its own business identification
monument sign on the Property, in a location which indicates that such sign
belongs

                                       6
<PAGE>

to the Building (or, if Tenant occupies all buildings on the Property, Tenant
shall have the exclusive right to all such monument signs), to be installed by
Landlord at its sole cost and expense. In the event the City of Sunnyvale only
approves the installation of one (1) monument sign for the Property, Tenant
shall have the right to place its business identification signage on the top of
said monument sign, which monument sign shall be installed by Landlord, at its
sole cost and expense. Such monument sign shall comply with all requirements
imposed by the City of Sunnyvale. Landlord may remove any signs (which have not
been approved in writing by Landlord), advertisements, banners, placards or
pictures so placed by Tenant on or within the Leased Premises, the exterior of
the Building, the Outside Areas or the Property and charge to Tenant the cost of
such removal, together with any costs incurred by Landlord to repair any damage
caused thereby, including any cost incurred to restore the surface (upon which
such sign was so affixed) to its original condition. Notwithstanding anything to
the contrary contained herein, Tenant shall remove all of Tenant's signs, repair
any damage caused thereby, and restore the surface upon which the sign was
affixed to its original condition, all to Landlord's reasonable satisfaction,
upon the termination of this Lease.

4.7 COMPLIANCE WITH LAWS AND PRIVATE RESTRICTIONS. Tenant shall abide by and
shall promptly observe and comply with, at its sole cost and expense, all Laws
and Private Restrictions respecting the use and occupancy of the Leased
Premises, the Building, the Outside Areas or the Property including, without
limitation, all Laws governing the use and/or disposal of Hazardous Materials
(except that Tenant shall not be responsible for any Hazardous Materials at the
Leased Premises, the Building, the Outside Areas or the Property prior to the
Delivery Date), and shall defend with competent counsel, indemnify and hold
Landlord harmless from any claims, damages or liability resulting from Tenant's
failure to so abide, observe, or comply. Tenant's obligations hereunder shall
survive the expiration or sooner termination of this Lease.

4.8 COMPLIANCE WITH INSURANCE REQUIREMENTS. With respect to any insurance
policies required or permitted to be carried by Landlord in accordance with the
provision of this Lease, copies of which have been or will, upon Tenant's
written request therefor, be provided to Tenant, Tenant shall not conduct nor
permit any other person to conduct any activities nor keep, store or use (or
allow any other person to keep, store or use) any item or thing within the
Leased Premises, the Building, the Outside Areas or the Property which (i) is
prohibited under the terms of any such policies, (ii) could result in the
termination of the coverage afforded under any of such policies, (iii) could
give to the insurance carrier the right to cancel any of such policies, or (iv)
could cause an increase in the rates (over standard rates) charged for the
coverage afforded under any of such policies. Tenant shall comply with all
requirements of any insurance company, insurance underwriter, or Board of Fire
Underwriters which are necessary to maintain, at standard rates, the insurance
coverages carried by either Landlord or Tenant pursuant to this Lease.

4.9 LANDLORD'S RIGHT TO ENTER. Landlord and its agents shall have the right to
enter the Leased Premises during normal business hours after giving Tenant
reasonable notice and subject to Tenant's reasonable security measures for the
purpose of (i) inspecting the same; (ii) showing the Leased Premises to
prospective purchasers, mortgagees or tenants; (iii) making necessary
alterations, additions or repairs; and (iv) performing any of Tenant's
obligations when Tenant has failed to do so. Landlord shall have the right to
enter the Leased Premises during normal business hours (or as otherwise agreed),
subject to Tenant's reasonable security measures, for purposes of supplying any
maintenance or services agreed to be supplied by Landlord. Landlord shall have
the right to enter the Outside Areas during normal business hours for purposes
of (i) inspecting the exterior of the Building and the Outside Areas; (ii)
posting notices of nonresponsibility (and for such purposes Tenant shall provide
Landlord at least thirty days' prior written notice of any work to be performed
on the Leased Premises); and (iii) supplying any services to be provided by
Landlord. Any entry into the Leased Premises or the Outside Areas obtained by
Landlord in accordance with this paragraph shall not under any circumstances be
construed or deemed to be a forcible or unlawful entry into, or a detainer of,
the Leased Premises, or an eviction, actual or constructive of Tenant from the
Leased Premises or any portion thereof. In exercising its rights under this
Section 4.9, Landlord shall use commercially reasonable efforts to minimize
interference with Tenant's use of the Leased Premises and the Outside Areas.

4.10 USE OF OUTSIDE AREAS. Tenant, in its use of the Outside Areas, shall at all
times keep the Outside Areas in a safe condition free and clear of all
materials, equipment, debris, trash (except within existing enclosed trash
areas), inoperable vehicles, and other items which are not specifically
permitted by Landlord to be stored or located thereon by Tenant. If, in the
opinion of Landlord, unauthorized persons are using any of the Outside Areas by
reason of, or under claim of, the express or implied authority or consent of
Tenant, then Tenant, upon demand of Landlord, shall restrain, to the fullest
extent then allowed by Law, such unauthorized use, and shall initiate such
appropriate proceedings as may be required to so restrain such use. Landlord
reserves the right to grant easements and access rights to others for use of the
Outside Areas and shall not be liable to Tenant for any diminution in Tenant's
right to use the Outside Areas as a result; provided, however, that Landlord
shall not exercise its rights pursuant to this Section 4.10 in a manner which
materially and adversely affects Tenant's ability to use the Leased Premises and
the Outside Areas for the Permitted Use or materially and adversely affects
Tenant's parking rights.

4.11 ENVIRONMENTAL PROTECTION. Tenant's obligations under this Section 4.11
shall survive the expiration or termination of this Lease.

      (a) As used herein, the term "Hazardous Materials" shall mean any toxic or
hazardous substance, material or waste or any pollutant or infectious or
radioactive material, including but not limited to those substances, materials
or wastes regulated now or in the future under any of the following statutes or
regulations and any and all of those substances included within the definitions
of "hazardous substances," "hazardous materials," "hazardous waste," "hazardous
chemical substance or mixture," "imminently hazardous chemical substance or
mixture," "toxic substances," "hazardous air pollutant," "toxic pollutant," or
"solid waste" in the (a) Comprehensive Environmental

                                       7
<PAGE>

Response, Compensation and Liability Act of 1990 ("CERCLA" or "Superfund"), as
amended by the Superfund Amendments and Reauthorization Act of 1986 ("SARA"), 42
U.S.C. Section 9601 et seq., (b) Resource Conservation and Recovery Act of 1976
("RCRA"), 42 U.S.C. Section 6901 et seq., (c) Federal Water Pollution Control
Act ("FSPCA"), 33 U.S.C. Section 1251 et seq., (d) Clean Air Act ("CAA"), 42
U.S.C. Section 7401 et seq., (e) Toxic Substances Control Act ("TSCA"), 14
U.S.C. Section 2601 et seq., (f) Hazardous Materials Transportation Act, 49
U.S.C. Section 1801, et seq., (g) Carpenter-Presley-Tanner Hazardous Substance
Account Act ("California Superfund"), Cal. Health & Safety Code Section 25300 et
seq., (h) California Hazardous Waste Control Act, Cal. Health & Safety code
Section 25100 et seq., (i) Porter-Cologne Water Quality Control Act
("Porter-Cologne Act"), Cal. Water Code Section 13000 et seq., (j) Hazardous
Waste Disposal Land Use Law, Cal. Health & Safety codes Section 25220 et seq.,
(k) Safe Drinking Water and Toxic Enforcement Act of 1986 ("Proposition 65"),
Cal. Health & Safety code Section 25249.5 et seq., (l) Hazardous Substances
Underground Storage Tank Law, Cal. Health & Safety code Section 25280 et seq.,
(m) Air Resources Law, Cal. Health & Safety Code Section 39000 et seq., and (n)
regulations promulgated pursuant to said laws or any replacement thereof, or as
similar terms are defined in the federal, state and local laws, statutes,
regulations, orders or rules. Hazardous Materials shall also mean any and all
other biohazardous wastes and substances, materials and wastes which are, or in
the future become, regulated under applicable Laws for the protection of health
or the environment, or which are classified as hazardous or toxic substances,
materials or wastes, pollutants or contaminants, as defined, listed or regulated
by any federal, state or local law, regulation or order or by common law
decision, including, without limitation, (i) trichloroethylene,
tetrachloroethylene, perchloroethylene and other chlorinated solvents, (ii) any
petroleum products or fractions thereof, (iii) asbestos, (iv) polychlorinted
biphenyls, (v) flammable explosives, (vi) urea formaldehyde, (vii) radioactive
materials and waste, and (viii) materials and wastes that are harmful to or may
threaten human health, ecology or the environment.

      (b) Notwithstanding anything to the contrary in this Lease, Tenant, at its
sole cost, shall comply with all Laws relating to the storage, use and disposal
of Hazardous Materials by Tenant, its subtenants, their respective agents,
employees, contractors or invitees (collectively, the "Tenant Parties"). Tenant
shall not store, use or dispose of any Hazardous Materials except for those
Hazardous Materials listed in a Hazardous Materials management plan ("HMMP")
which Tenant shall deliver to Landlord upon execution of this Lease and update
at least annually with Landlord ("Permitted Materials") which may be used,
stored and disposed of provided (i) such Permitted Materials are used, stored,
transported, and disposed of in strict compliance with applicable laws, (ii)
such Permitted Materials shall be limited to the materials listed on and may be
used only in the quantities specified in the HMMP, and (iii) Tenant shall
provide Landlord with copies of all material safety data sheets and other
documentation required under applicable Laws in connection with Tenant's use of
Permitted Materials as and when such documentation is provided to any regulatory
authority having jurisdiction, in no event shall Tenant cause or permit to be
discharged into the plumbing or sewage system of the Building or onto the land
underlying or adjacent to the Building any Hazardous Materials. Tenant shall be
solely responsible for and shall defend, indemnify, and hold Landlord and its
agents harmless from and against all claims, costs and liabilities, including
attorneys' fees and costs, arising out of or in connection with Tenant's
storage, use and/or disposal of Hazardous Materials. If the presence of
Hazardous Materials on the Leased Premises caused or permitted by Tenant results
in contamination or deterioration of water or soil, then Tenant shall promptly
take any and all action necessary to clean up such contamination as required by
Law, but the foregoing shall in no event be deemed to constitute permission by
Landlord to allow the presence of such Hazardous Materials. At any time prior to
the expiration of the Lease Term if Tenant has a reasonable basis to suspect
that there has been any release or the presence of Hazardous Materials in the
ground or ground water on the Leased Premises which did not exist upon
commencement of the Lease Term, Tenant shall have the right to conduct
appropriate tests of water and soil and to deliver to Landlord the results of
such tests to demonstrate that no contamination in excess of permitted levels
has occurred as a result of Tenant's use of the Leased Premises. Tenant shall
further be solely responsible for, and shall defend, indemnify, and hold
Landlord and its agents harmless from and against all claims, costs and
liabilities, including attorneys' fees and costs, arising out of or in
connection with any removal, cleanup and restoration work and materials required
hereunder to return the Leased Premises and any other property of whatever
nature to their condition existing prior to the appearance of the Hazardous
Materials, to the extent such removal, cleanup and restoration work is required
by Law.

      (c) Upon termination or expiration of the Lease, Tenant at its sole
expense shall cause all Hazardous Materials placed in or about the Leased
Premises, the Building and/or the Property by any Tenant Parties, and all
installations (whether interior or exterior) made by or on behalf of Tenant
relating to the storage, use, disposal or transportation of Hazardous Materials
to be removed from the property and transported for use, storage or disposal in
accordance and compliance with all Laws and other requirements respecting
Hazardous Materials used or permitted to be used by Tenant. Tenant shall apply
for and shall obtain from all appropriate regulatory authorities (including any
applicable fire department or regional water quality control board) all permits,
approvals and clearances necessary for the closure of the Property and shall
take all other actions as may be required to complete the closure of the
Building and the Property. In addition, prior to vacating the Leased Premises,
Tenant shall undertake and submit to Landlord an environmental site assessment
from an environmental consulting company reasonably acceptable to Landlord which
site assessment shall evidence Tenant's compliance with this Paragraph 4.11.

      (d) At any time prior to expiration of the Lease term, subject to
reasonable prior notice (not less than forty-eight (48) hours) and Tenant's
reasonable security requirements and provided such activities do not
unreasonably interfere with the conduct of Tenant's business at the Leased
Premises, Landlord shall have the right to enter in and upon the Property,
Building and Leased Premises in order to conduct appropriate tests of water and
soil to determine whether levels of any Hazardous Materials in excess of legally
permissible levels has occurred as a result of any Tenant Parties' use thereof .
Landlord shall furnish copies of all such test results and reports to Tenant
and, at Tenant's option and cost, shall permit split sampling for testing and
analysis by Tenant. Such testing shall be at Tenant's expense if Landlord has a
reasonable basis for suspecting and confirms the presence of Hazardous Materials
in the soil or surface or ground water in, on, under, or about the Property, the
Building or the Leased Premises, which has been caused by or resulted from the
activities of any Tenant Parties.

                                       8
<PAGE>

      (e) Landlord may voluntarily cooperate in a reasonable manner with the
efforts of all governmental agencies in reducing actual or potential
environmental damage. Tenant shall not be entitled to terminate this Lease or to
any reduction in or abatement of rent by reason of such compliance or
cooperation. Tenant agrees at all times to cooperate fully with the requirements
and recommendations of governmental agencies regulating, or otherwise involved
in, the protection of the environment.

4.12 RULES AND REGULATIONS. In the event Juniper Networks, Inc. is no longer the
sole tenant of the Building, Landlord shall have the right from time to time to
establish reasonable rules and regulations and/or amendments or additions
thereto respecting the use of the Leased Premises and the Outside Areas for the
care and orderly management of the Property. Upon delivery to Tenant of a copy
of such rules and regulations or any amendments or additions thereto, Tenant
shall comply with such rules and regulations. A violation by Tenant of any of
such rules and regulations shall constitute a default by Tenant under this
Lease. If there is a conflict between the rules and regulations and any of the
provisions of this Lease, the provisions of this Lease shall prevail. Landlord
shall not be responsible or liable to Tenant for the violation of such rules and
regulations by any other tenant of the Property.

4.13 RESERVATIONS. Landlord reserves the right from time to time to grant,
without the consent or joinder of Tenant, such easements, rights of way and
dedications that Landlord deems necessary, and to cause the recordation of
parcel maps and covenants, conditions and restrictions, so long as such
easements, rights of way, dedications and covenants, conditions and restrictions
do not materially and adversely affect the use of the Leased Premises by Tenant,
materially and adversely affect Tenant's parking rights, and do not prohibit any
Permitted Use. Tenant agrees to execute any documents reasonably request by
Landlord to effectuate any such easement rights, dedications, maps or covenants,
conditions and restrictions.

                                   ARTICLE 5

                  REPAIRS, MAINTENANCE, SERVICES AND UTILITIES

5.1 REPAIR AND MAINTENANCE. Except in the case of damage to or destruction of
the Leased Premises, the Building, the Outside Areas or the Property caused by
an act of God or other peril, in which case the provisions of Article 10 shall
control, the parties shall have the following obligations and responsibilities
with respect to the repair and maintenance of the Leased Premises, the Building,
the Outside Areas, and the Property.

      (a) TENANT'S OBLIGATIONS. Tenant shall, at all times during the Lease Term
and at its sole cost and expense, regularly clean and continuously keep and
maintain in good order, condition and repair the Leased Premises and every part
thereof including, without limiting the generality of the foregoing, (i) all
interior walls, floors and ceilings, (ii) all windows, doors and skylights,
(iii) all electrical wiring, conduits, connectors and fixtures, (iv) all
plumbing, pipes, sinks, toilets, faucets and drains, (v) all lighting fixtures,
bulbs and lamps and all heating, ventilating and air conditioning equipment, and
(vi) all entranceways to the Leased Premises. Tenant shall hire, at Tenant's
sole cost and expense, a licensed heating, ventilating and air conditioning
contractor to regularly and periodically (not less frequently than every three
months) inspect and perform required maintenance on the heating, ventilating and
air conditioning equipment and systems serving the Leased Premises. Tenant shall
hire, at Tenant's sole cost and expense, a licensed roofing contractor to
regularly and periodically (not less frequently than semi-annually) inspect and
perform required maintenance on the roof of the Building. If Tenant shall be in
default of its obligations to maintain the heating, ventilating and air
conditioning equipment and systems or roof, Landlord may, at its election,
contract in its own name for such regular and periodic inspections and
maintenance of the heating, ventilating and air conditioning equipment and
systems and/or roof, and charge to Tenant, as Additional Rent, the cost thereof.
Tenant shall, at its sole cost and expense, repair all damage to the Leased
Premises, the Building, the Outside Areas or the Property caused by the
activities of Tenant, its employees, invitees or contractors promptly following
written notice from Landlord to so repair such damages (subject to Section 9.3
of this Lease). If Tenant shall fail to perform the required maintenance or fail
to make repairs required of it pursuant to this paragraph within a reasonable
period of time following notice from Landlord to do so, then Landlord may, at
its election and without waiving any other remedy it may otherwise have under
this Lease or at law, perform such maintenance or make such repairs and charge
to Tenant, as Additional Rent, the costs so incurred by Landlord for same. All
glass within or a part of the Leased Premises, both interior and exterior, is at
the sole risk of Tenant and any broken glass shall promptly be replaced by
Tenant at Tenant's expense with glass of the same kind, size and quality.
Notwithstanding the foregoing, in the event that, due to normal wear and tear
(and not due to other factors, including, without limitation, Tenant's misuse,
overuse or Tenant's alterations, improvements or modifications to the Leased
Premises, the Outside Areas or the Building), Tenant would be required by this
Section 5.1(a) to make a repair or replacement that would be considered a
"capital improvement" as determined in accordance with generally accepted
accounting principles, Landlord shall make such repair or replacement and charge
to Tenant, as Additional Rent, the cost thereof (provided that the cost of such
repair or replacement shall be amortized over its useful life and only the
amortizing portion of such cost shall be included in Additional Rent on a
monthly basis).

      (b) LANDLORD'S OBLIGATION. Landlord shall at its sole cost and expense, at
all times during the Lease Term, maintain in good condition and repair the
foundation, the footings, the roof screen, the roof screen penetrations, the
roof structure, load-bearing and exterior walls of the Building. Landlord shall,
at all times during the Lease Term, regularly and continuously keep and maintain
in good order and repair and in a clean and safe condition the Outside Areas,
and charge to Tenant, as Additional Rent, the cost

                                       9
<PAGE>

thereof. Landlord shall regularly and periodically sweep and clean the driveways
and parking areas, and charge to Tenant, as Additional Rent, the cost thereof.

5.2 UTILITIES. Tenant shall arrange at its sole cost and expense and in its own
name, for the supply of gas and electricity to the Leased Premises. In the event
that such services are not separately metered, Tenant shall, at its sole
expense, cause such meters to be installed. Landlord shall maintain the water
meter(s) in its own name; provided, however, that if at any time during the
Lease Term Landlord shall require Tenant to put the water service in Tenant's
name, Tenant shall do so at Tenant's sole cost. Tenant shall be responsible for
determining if the local supplier of water, gas and electricity can supply the
needs of Tenant and whether or not the existing water, gas and electrical
distribution systems within the Building and the Leased Premises are adequate
for Tenant's needs. Tenant shall be responsible for determining if the existing
sanitary and storm sewer systems now servicing the Leased Premises and the
Property are adequate for Tenant's needs. Tenant shall pay all charges for
water, gas, electricity and storm and sanitary sewer services as so supplied to
the Leased Premises, irrespective of whether or not the services are maintained
in Landlord's or Tenant's name.

5.3 SECURITY. Tenant acknowledges that Landlord has not undertaken any duty
whatsoever to provide security for the Leased Premises, the Building, the
Outside Areas or the Property and, accordingly, Landlord is not responsible for
the security of same or the protection of Tenant's property or Tenant's
employees, invitees or contractors. To the extent Tenant determines that such
security or protection services are advisable or necessary, Tenant shall arrange
for and pay the costs of providing same.

5.4 ENERGY AND RESOURCE CONSUMPTION. Landlord may voluntarily cooperate in a
reasonable manner with the efforts of governmental agencies and/or utility
suppliers in reducing energy or other resource consumption within the Property.
Tenant shall not be entitled to terminate this Lease or to any reduction in or
abatement of rent by reason of such compliance or cooperation. Tenant agrees at
all times to cooperate fully with Landlord and to abide by all reasonable rules
established by Landlord (i) in order to maximize the efficient operation of the
electrical, heating, ventilating and air conditioning systems and all other
energy or other resource consumption systems with the Property and/or (ii) in
order to comply with the requirements and recommendations of utility suppliers
and governmental agencies regulating the consumption of energy and/or other
resources.

5.5 LIMITATION OF LANDLORD'S LIABILITY. Landlord shall not be liable to Tenant
for injury to Tenant, its employees, agents, invitees or contractors, damage to
Tenant's property or loss of Tenant's business or profits, nor shall Tenant be
entitled to terminate this Lease or to any reduction in or abatement of rent by
reason of (i) Landlord's failure to provide security services or systems within
the Property for the protection of the Leased Premises, the Building or the
Outside Areas, or the protection of Tenant's property or Tenant's employees,
invitees, agents or contractors, or (ii) Landlord's failure to perform any
maintenance or repairs to the Leased Premises, the Building, the Outside Areas
or the Property until Tenant shall have first notified Landlord, in writing, of
the need for such maintenance or repairs, and then only after Landlord shall
have had a reasonable period of time following its receipt of such notice within
which to perform such maintenance or repairs, or (iii) any failure,
interruption, rationing or other curtailment in the supply of water, electric
current, gas or other utility service to the Leased Premises, the Building, the
Outside Areas or the Property from whatever cause (other than to the extent
caused by Landlord's active negligence or willful misconduct), or (iv) the
unauthorized intrusion or entry into the Leased Premises by third parties (other
than Landlord).

                                   ARTICLE 6

                          ALTERATIONS AND IMPROVEMENTS

6.1 BY TENANT. Tenant shall not make any alterations to or modifications of the
Leased Premises or construct any improvements within the Leased Premises until
Landlord shall have first approved, in writing, the plans and specifications
therefor, which approval shall not be unreasonably withheld or delayed.
Landlord's approval shall be deemed given if not denied by Landlord in a written
notice to Tenant delivered within fifteen (15) days following receipt of
Tenant's written request. Tenant's written request shall also contain a request
for Landlord to elect whether or not it will require Tenant to remove the
subject alterations, modifications or improvements at the expiration or earlier
termination of this Lease. If such additional request is not included, Landlord
may make such election at the expiration or earlier termination of this Lease
(and for purposes of Tenant's removal obligations set forth in Section 2.6
above, Landlord shall be deemed to have made the election at the time the
alterations, modifications or improvements were completed). All modifications,
alterations or improvements, once approved by Landlord, shall be made,
constructed or installed by Tenant at Tenant's expense (including all permit
fees and governmental charges related thereto), using a licensed contractor
first approved by Landlord, in substantial compliance with the Landlord-approved
plans and specifications therefor. All work undertaken by Tenant shall be done
in accordance with all Laws and in a good and workmanlike manner using new
materials of good quality. Tenant shall not commence the making of any such
modifications or alterations or the construction of any such improvements until
(i) all required governmental approvals and permits shall have been obtained,
(ii) all requirements regarding insurance imposed by this Lease have been
satisfied, (iii) Tenant shall have given Landlord at least five business days
prior written notice of its intention to commence such work so that Landlord may
post and file notices of non-responsibility, and (iv) if requested by Landlord,
Tenant shall have obtained contingent liability and broad form builder's risk
insurance in an amount satisfactory to Landlord in its reasonable discretion to
cover any perils relating to the proposed work not covered by insurance carried
by Tenant pursuant to Article 9. In no event shall Tenant make any modification,
alterations or improvements whatsoever to the Outside Areas or the exterior or
structural components of the Building including, without limitation, any cuts or

                                       10
<PAGE>

penetrations in the floor, roof or exterior walls of the Leased Premises (except
to the extent Tenant has obtained Landlord's approval pursuant to Section 4.2).
As used in this Article, the term "modifications, alterations and/or
improvements" shall include, without limitation, the installation of additional
electrical outlets, overhead lighting fixtures, drains, sinks, partitions,
doorways, or the like. Notwithstanding the foregoing, Tenant, without Landlord's
prior written consent, shall be permitted to make non-structural alterations to
the Building, provided that: (a) such alterations do not exceed $20,000
individually, (b) Tenant shall timely provide Landlord the notice required
pursuant to Paragraph 4.9 above, (c) Tenant shall notify Landlord in writing
within thirty (30) days of completion of the alteration and deliver to Landlord
a set of the plans and specifications therefor, either "as built" or marked to
show construction changes made, and (d) Tenant shall, upon Landlord's request,
remove the alteration at the termination of the Lease and restore the Leased
Premises to their condition prior to such alteration.

6.2 OWNERSHIP OF IMPROVEMENTS. All modifications, alterations and improvements
made or added to the Leased Premises by Tenant (other than Tenant's inventory,
equipment, movable furniture, wall decorations and trade fixtures) shall be
deemed real property and a part of the Leased Premises, but shall remain the
property of Tenant during the Lease. Any such modifications, alterations or
improvements, once completed, shall not be altered or removed from the Leased
Premises during the Lease Term without Landlord's written approval first
obtained in accordance with the provisions of Paragraph 6.1 above. At the
expiration or sooner termination of this Lease, all such modifications,
alterations and improvements other than Tenant's inventory, equipment, movable
furniture, wall decorations and trade fixtures, shall automatically become the
property of Landlord and shall be surrendered to Landlord as part of the Leased
Premises as required pursuant to Article 2, unless Landlord shall require Tenant
to remove any of such modifications, alterations or improvements in accordance
with the provisions of Article 2, in which case Tenant shall so remove same.
Landlord shall have no obligations to reimburse Tenant for all or any portion of
the cost or value of any such modifications, alterations or improvements so
surrendered to Landlord. All modifications, alterations or improvements which
are installed or constructed on or attached to the Leased Premises by Landlord
and/or at Landlord's expense shall be deemed real property and a part of the
Leased Premises and shall be property of Landlord. All lighting, plumbing,
electrical, heating, ventilating and air conditioning fixtures, partitioning,
window coverings, wall coverings and floor coverings installed by Tenant shall
be deemed improvements to the Leased Premises and not trade fixtures of Tenant.
Landlord shall have no lien or interest whatsoever in any of Tenant's property
or equipment located in the Leased Premises or elsewhere, and Landlord waives
any such liens and interests and Landlord hereby agrees to execute a Landlord
Waiver with respect thereto in favor of any lender or equipment lessor of Tenant
strictly in the form attached as ExhibitE.

6.3 ALTERATIONS REQUIRED BY LAW. Tenant shall make all modifications,
alterations and improvements to the Leased Premises, at its sole cost, that are
required by any Law because of (i) Tenant's use or occupancy of the Leased
Premises, the Building, the Outside Areas or the Property, (ii) Tenant's
application for any permit or governmental approval, or (iii) Tenant's making of
any modifications, alterations or improvements to or within the Leased Premises.
If Landlord shall, at any time during the Lease Term, be required by any
governmental authority to make any modifications, alterations or improvements to
the Building or the Property, the cost incurred by Landlord in making such
modifications, alterations or improvements, including interest at a rate equal
to the greater of (a) 12%, or (b) the sum of that rate quoted by Wells Fargo
Bank, N.T. & S.A. from time to time as its prime rate, plus two percent (2%)
("Wells Prime Plus Two") (but in no event more than the maximum interest rate
permitted by law), shall be amortized by Landlord over the useful life of such
modifications, alterations or improvements, as determined in accordance with
generally accepted accounting principles, and the monthly amortized cost of such
modifications, alterations and improvements as so amortized shall be considered
a Property Maintenance Cost.

6.4 LIENS. Tenant shall keep the Property and every part thereof free from any
lien, and shall pay when due all bills arising out of any work performed,
materials furnished, or obligations incurred by Tenant, its agents, employees or
contractors relating to the Property. If any such claim of lien is recorded
against Tenant's interest in this Lease, the Property or any part thereof,
Tenant shall bond against, discharge or otherwise cause such lien to be entirely
released within ten days after the same has been recorded. Tenant's failure to
do so shall be conclusively deemed a material default under the terms of this
Lease.

                                   ARTICLE 7

                       ASSIGNMENT AND SUBLETTING BY TENANT

7.1 BY TENANT. Tenant shall not sublet the Leased Premises or any portion
thereof or assign its interest in this Lease, whether voluntarily or by
operation of Law, without Landlord's prior written consent which shall not be
unreasonably withheld. Any attempted subletting or assignment without Landlord's
prior written consent, at Landlord's election, shall constitute a default by
Tenant under the terms of this Lease. The acceptance of rent by Landlord from
any person or entity other than Tenant, or the acceptance of rent by Landlord
from Tenant with knowledge of a violation of the provisions of this paragraph,
shall not be deemed to be a waiver by Landlord of any provision of this Article
or this Lease or to be a consent to any subletting by Tenant or any assignment
of Tenant's interest in this Lease. Without limiting the circumstances in which
it may be reasonable for Landlord to withhold its consent to an assignment or
subletting, Landlord and Tenant acknowledge that it shall be reasonable for
Landlord to withhold its consent in the following instances:

      (a) the proposed assignee or sublessee is a governmental agency;

                                       11
<PAGE>

      (b) in Landlord's reasonable judgment, the use of the Leased Premises by
the proposed assignee or sublessee would involve occupancy by other than a
Permitted Use as set forth in Article 1, would entail any alterations which
would lessen the value of the leasehold improvements in the Leased Premises, or
would require increased services by Landlord;

      (c) in Landlord's reasonable judgment, the financial worth of the proposed
assignee is less than that of Tenant or does not meet the credit standards
applied by Landlord at the time of the proposed assignment;

      (d) the proposed assignee or sublessee (or any of its affiliates) has been
in material default under a lease, has been in litigation with a previous
landlord due to a default under a lease, or in the ten years prior to the
assignment or sublease has filed for bankruptcy protection, has been the subject
of an involuntary bankruptcy, or has been adjudged insolvent;

      (e) Landlord has experienced a previous default by or is in litigation
with the proposed assignee or sublessee;

      (f) in Landlord's reasonable judgment, the Leased Premises, or the
relevant part thereof, will be used in a manner that will violate any negative
covenant as to use contained in this Lease;

      (g) the use of the Leased Premises by the proposed assignee or sublessee
will violate any applicable law, ordinance or regulation;

      (h) the proposed assignment or sublease fails to include all of the terms
and provisions required to be included therein pursuant to this Article 7;

      (i) Tenant is in default of any obligation of Tenant under this Lease, or
Tenant has defaulted on any of its payment obligations under this Lease on three
or more occasions during the 12 months preceding the date that Tenant shall
request consent; or

      (j) in the case of a subletting of less than the entire Leased Premises,
if the subletting would result in the division of any floor of the Building into
more than two subleased parcels or would require improvements to be made outside
of the Leased Premises.

7.2 MERGER, REORGANIZATION, OR SALE OF ASSETS. Each of the following shall be
deemed a voluntary assignment of Tenant's interest in this Lease: (a)
dissolution, merger, consolidation or other reorganization of Tenant; or (b) at
any time that the capital stock of Tenant is not publicly traded on a recognized
exchange, the sale or transfer in one or more transactions to one or more
related parties of a controlling percentage of the capital stock of Tenant; or
(c) or the sale or transfer of all or substantially all of the assets of Tenant.
The phrase "controlling percentage" means the ownership of and the right to vote
stock possessing more than fifty percent of the total combined voting power of
all classes of Tenant's capital stock issued, outstanding and entitled to vote
for the election of directors. If Tenant is a partnership, a withdrawal or
change, voluntary, involuntary or by operation of Law, of any general partner,
or the dissolution of the partnership, shall be deemed a voluntary assignment of
Tenant's interest in this Lease. Notwithstanding the foregoing, Tenant (or any
Permitted Assignee, as defined herein) may, without Landlord's prior written
consent and without being subject to any of the provisions of this Article 7,
including without limitation, Landlord's right to recapture any portion of the
Leased Premises, sublet the Leased Premises or assign this Lease to
(individually, a "Permitted Assignee," collectively, "Permitted Assignees"): (i)
a subsidiary, affiliate, division, corporation or joint venture controlling,
controlled by or under common control with Tenant; or (ii) a successor
corporation related to Tenant by merger, consolidation, nonbankruptcy
reorganization, or government action; or (iii) a purchaser of all or
substantially all of the assets of Tenant; provided that either (1) Tenant shall
remain primarily liable under the Lease (except in the event it is not the
surviving entity in the merger) or (2) that any Permitted Assignee under (i),
(ii) or (iii) above has a net worth equal to or greater than Tenant and does not
have any contingent or off-balance sheet liabilities that make it less credit
worthy than Tenant. In the event any proposed assignee or subtenant under (i),
(ii) or (iii) above has a net worth less than Tenant or has contingent or
off-balance sheet liabilities that make it less credit worthy than Tenant,
Landlord's consent (pursuant to Section 7.1 above) shall be required and all of
the terms and conditions of this Article 7 shall apply, except that Landlord
shall not be entitled to terminate this Lease pursuant to Section 7.3, and
Landlord shall not be entitled to any assignment consideration or excess rentals
pursuant to Section 7.5 of this Lease. If any proposed assignee or subtenant
under (i), (ii) or (iii) above does not qualify as a Permitted Assignee because
it has a net worth which is less than Tenant or has contingent or off-balance
sheet liabilities that make it less creditworthy than Tenant, then in the event
Landlord nevertheless consents (pursuant to the provisions of Section 7.1 above)
to such proposed assignee or subtenant, such proposed assignee or subtenant
shall constitute a Permitted Assignee under this Lease.

7.3 LANDLORD'S ELECTION. If Tenant shall desire to assign its interest under the
Lease or to sublet the Leased Premises, Tenant must first notify Landlord, in
writing, of its intent to so assign or sublet, at least thirty (30) days in
advance of the date it intends to so assign its interest in this Lease or sublet
the Leased Premises but not sooner than one hundred eighty days in advance of
such date, specifying in detail the terms of such proposed assignment or
subletting, including the name of the proposed assignee or sublessee, the
property assignee's or sublessee's intended use of the Leased Premises, current
financial statements (including a balance sheet, income statement and statement
of cash flow, all prepared in accordance with generally accepted accounting
principles) of such proposed assignee or sublessee, the form of documents to be
used in effectuating such assignment or subletting and such other information as
Landlord may reasonably request. Landlord shall have a period of ten (10)
business days following receipt of such notice and the required information
within which to do one of the following: (i) consent to such requested
assignment or subletting subject to Tenant's compliance with the

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<PAGE>

conditions set forth in Paragraph 7.4 below, or (ii) refuse to so consent to
such requested assignment or subletting, provided that such consent shall not be
unreasonably refused, or (iii) in the case of an assignment of this Lease or
sublet of 100% of the Leased Premises, terminate this Lease. During such ten
(10) business day period, Tenant covenants and agrees to supply to Landlord,
upon request, all necessary or relevant information which Landlord may
reasonably request respecting such proposed assignment or subletting and/or the
proposed assignee or sublessee. Notwithstanding the foregoing, if Landlord
elects to terminate the Lease as provided herein, Landlord shall notify Tenant
thereof during such ten (10) business day period and Tenant shall have ten (10)
business days thereafter to either (i) accept Landlord's termination or (ii)
rescind its request for consent to the assignment or subletting, in which case
the Lease shall continue in full force and effect between Tenant and Landlord.

7.4 CONDITIONS TO LANDLORD'S CONSENT. If Landlord elects to consent, or shall
have been ordered to so consent by a court of competent jurisdiction, to such
requested assignment or subletting, such consent shall be expressly conditioned
upon the occurrence of each of the conditions below set forth, and any purported
assignment or subletting made or ordered prior to the full and complete
satisfaction of each of the following conditions shall be void and, at the
election of Landlord, which election may be exercised at any time following such
a purported assignment or subletting but prior to the satisfaction of each of
the stated conditions, shall constitute a material default by Tenant under this
Lease until cured by satisfying in full each such condition by the assignee or
sublessee. The conditions are as follows:

      (a) Landlord having approved in form and substance the assignment or
sublease agreement and any ancillary documents, which approval shall not be
unreasonably withheld by Landlord if the requirements of this Article 7 are
otherwise complied with.

      (b) Each such sublessee or assignee having agreed, in writing satisfactory
to Landlord and its counsel and for the benefit of Landlord, to assume, to be
bound by, and to perform the obligations of this Lease to be performed by Tenant
which relate to space being subleased.

      (c) Tenant having fully and completely performed all of its obligations
under the terms of this Lease through and including the date of such assignment
or subletting.

      (d) Tenant having reimbursed to Landlord all reasonable costs and
reasonable attorneys' fees incurred by Landlord in conjunction with the
processing and documentation of any such requested subletting or assignment.

      (e) Tenant having delivered to Landlord a complete and fully-executed
duplicate original of such sublease agreement or assignment agreement (as
applicable) and all related agreements.

      (f) Tenant having paid, or having agreed in writing to pay as to future
payments, to Landlord fifty percent (50%) of all assignment consideration or
excess rentals to be paid to Tenant or to any other on Tenant's behalf or for
Tenant's benefit for such assignment or subletting as follows:

            (i) If Tenant assigns its interest under this Lease and if all or a
portion of the consideration for such assignment is to be paid by the assignee
at the time of the assignment, that Tenant shall have paid to Landlord and
Landlord shall have received an amount equal to fifty percent (50%) of the
assignment consideration so paid or to be paid (whichever is the greater) at the
time of the assignment by the assignee; or

            (ii) If Tenant assigns its interest under this Lease and if Tenant
is to receive all or a portion of the consideration for such assignment in
future installments, that Tenant and Tenant's assignee shall have entered into a
written agreement with and for the benefit of Landlord satisfactory to Landlord
and its counsel whereby Tenant and Tenant's assignee jointly agree to pay to
Landlord an amount equal to fifty percent (50%) of all such future assignment
consideration installments to be paid by such assignee as and when such
assignment consideration is so paid.

            (iii) If Tenant subleases the Leased Premises, that Tenant and
Tenant's sublessee shall have entered into a written agreement with and for the
benefit of Landlord satisfactory to Landlord and its counsel whereby Tenant and
Tenant's sublessee jointly agree to pay to Landlord fifty percent (50%) of all
excess rentals to be paid by such sublessee as and when such excess rentals are
so paid.

7.5 ASSIGNMENT CONSIDERATION AND EXCESS RENTALS DEFINED. For purposes of this
Article, including any amendment to this Article by way of addendum or other
writing, the term "assignment consideration" shall mean all consideration to be
paid by the assignee to Tenant or to any other party on Tenant's behalf or for
Tenant's benefit as consideration for such assignment, after deduction for
reasonable leasing commissions and reasonable legal fees incurred by Tenant in
connection with such assignment and, during the first six (6) years of the Lease
Term, the cost of tenant improvements made by Tenant at Tenant's sole cost and
expense to prepare the Leased Premises for the assignee, but without deduction
for any other costs or expenses, and the term "excess rentals" shall mean all
consideration to be paid by the sublessee to Tenant or to any other party on
Tenant's behalf or for Tenant's benefit for the sublease of the Leased Premises
in excess of the rent due to Landlord under the terms of this Lease for the same
period, after deduction for reasonable leasing commissions and reasonable legal
fees incurred by Tenant in connection with such sublease and, during the first
six (6) years of the Lease Term, the cost of tenant improvements made by Tenant
at Tenant's sole cost and expense to prepare the Leased Premises for the
subtenant, but without deduction for any other costs or expenses. Tenant agrees
that the portion of any assignment consideration and/or excess rentals arising
from any assignment or subletting by Tenant which is to be paid to Landlord
pursuant to this Article now is and shall then be the property of Landlord and
not the property of Tenant.

                                       13
<PAGE>

7.6 PAYMENTS. All payments required by this Article to be made to Landlord shall
be made in cash in full as and when they become due. At the time Tenant,
Tenant's assignee or sublessee makes each such payment to Landlord, Tenant or
Tenant's assignee or sublessee, as the case may be, shall deliver to Landlord an
itemized statement in reasonable detail showing the method by which the amount
due Landlord was calculated and certified by the party making such payment as
true and correct.

7.7 GOOD FAITH. The rights granted to Tenant by this Article are granted in
consideration of Tenant's express covenant that all pertinent allocations which
are made by Tenant between the rental value of the Leased Premises and the value
of any of Tenant's personal property which may be conveyed or leased generally
concurrently with and which may reasonably be considered a part of the same
transaction as the permitted assignment or subletting shall be made fairly,
honestly and in good faith. If Tenant shall breach this covenant, Landlord may
immediately declare Tenant to be in default under the terms of this Lease and
terminate this Lease and/or exercise any other rights and remedies Landlord
would have under the terms of this Lease in the case of a material default by
Tenant under this Lease.

7.8 EFFECT OF LANDLORD'S CONSENT. No subletting or assignment, even with the
consent of Landlord, shall relieve Tenant of its personal and primary obligation
to pay rent and to perform all of the other obligations to be performed by
Tenant hereunder. Consent by Landlord to one or more assignments of Tenant's
interest in this Lease or to one or more sublettings of the Leased Premises
shall not be deemed to be a consent to any subsequent assignment or subletting.
If Landlord shall have been ordered by a court of competent jurisdiction to
consent to a requested assignment or subletting, or such an assignment or
subletting shall have been ordered by a court of competent jurisdiction over the
objection of Landlord, such assignment or subletting shall not be binding
between the assignee (or sublessee) and Landlord until such time as all
conditions set forth in Paragraph 7.4 above have been fully satisfied (to the
extent not then satisfied) by the assignee or sublessee, including, without
limitation, the payment to Landlord of all agreed assignment considerations
and/or excess rentals then due Landlord.

                                   ARTICLE 8

                LIMITATION ON LANDLORD'S LIABILITY AND INDEMNITY

8.1 LIMITATION ON LANDLORD'S LIABILITY AND RELEASE. Landlord shall not be liable
to Tenant for, and Tenant hereby releases Landlord and its partners, principals,
members, officers, agents, employees, lenders, attorneys, and consultants from,
any and all liability, whether in contract, tort or on any other basis, for any
injury to or any damage sustained by Tenant, Tenant's agents, employees,
contractors or invitees, any damage to Tenant's property, or any loss to
Tenant's business, loss of Tenant's profits or other financial loss of Tenant
resulting from or attributable to the condition of, the management of, the
repair or maintenance of, the protection of, the supply of services or utilities
to, the damage in or destruction of the Leased Premises, the Building, the
Property or the Outside Areas, including without limitation (i) the failure,
interruption, rationing or other curtailment or cessation in the supply of
electricity, water, gas or other utility service to the Property, the Building
or the Leased Premises; (ii) the vandalism or forcible entry into the Building
or the Leased Premises; (iii) the penetration of water into or onto any portion
of the Leased Premises; (iv) the failure to provide security and/or adequate
lighting in or about the Property, the Building or the Leased Premises, (v) the
existence of any design or construction defects within the Property, the
Building or the Leased Premises; (vi) the failure of any mechanical systems to
function properly (such as the HVAC systems); (vii) the blockage of access to
any portion of the Property, the Building or the Leased Premises, except that
Tenant does not so release Landlord from such liability to the extent such
damage was proximately caused by Landlord's active negligence, willful
misconduct, or Landlord's failure to perform an obligation expressly undertaken
pursuant to this Lease after a reasonable period of time shall have lapsed
following receipt of written notice from Tenant to so perform such obligation.
In this regard, Tenant acknowledges that it is fully apprised of the provisions
of Law relating to releases, and particularly to those provisions contained in
Section 1542 of the California Civil Code which reads as follows:

        "A general release does not extend to claims which the creditor
        does not know or suspect to exist in his favor at the time of
        executing the release, which if known by him must have materially
        affected his settlement with the debtor."

Notwithstanding such statutory provision, and for the purpose of implementing a
full and complete release and discharge, Tenant hereby (i) waives the benefit of
such statutory provision and (ii) acknowledges that, subject to the exceptions
specifically set forth herein, the release and discharge set forth in this
paragraph is a full and complete settlement and release and discharge of all
claims and is intended to include in its effect, without limitation, all claims
which Tenant, as of the date hereof, does not know of or suspect to exist in its
favor.

8.2 TENANT'S INDEMNIFICATION OF LANDLORD. Tenant shall defend with competent
counsel satisfactory to Landlord any claims made or legal actions filed or
threatened against Landlord with respect to the violation of any Law, or the
death, bodily injury, personal injury, property damage, or interference with
contractual or property rights suffered by any third party, occurring within the
Leased Premises or resulting from Tenant's use or occupancy of the Leased
Premises, the Building or the Outside Areas, or resulting from Tenant's
activities in or about the Leased Premises, the Building, the Outside Areas or
the Property, and Tenant shall indemnify and hold Landlord, Landlord's partners,
principals, members, employees, agents and contractors harmless from any loss
liability, penalties, or expense whatsoever (including any loss attributable to
vacant space which otherwise would have been leased, but for such activities)
resulting therefrom, except to the extent proximately caused by the active
negligence or willful misconduct of Landlord or Landlord's

                                       14
<PAGE>

failure to perform an obligation expressly undertaken pursuant to this Lease
after a reasonable period of time shall have lapsed following receipt of written
notice from Tenant to so perform such obligation. This indemnity agreement shall
survive the expiration or sooner termination of this Lease.

                                   ARTICLE 9

                                    INSURANCE

9.1 TENANT'S INSURANCE. Tenant shall maintain insurance complying with all of
the following:

      (a) Tenant shall procure, pay for and keep in full force and effect, at
all times during the Lease Term, the following:

            (i) Comprehensive general liability insurance insuring Tenant
against liability for personal injury, bodily injury, death and damage to
property occurring within the Leased Premises, or resulting from Tenant's use or
occupancy of the Leased Premises, the Building, the Outside Areas or the
Property, or resulting from Tenant's activities in or about the Leased Premises
or the Property, with coverage in an amount equal to Tenant's Required Liability
Coverage (as set forth in Article 1), which insurance shall contain a "broad
form liability" endorsement insuring Tenant's performance of Tenant's
obligations to indemnify Landlord as contained in this Lease.

            (ii) Fire and property damage insurance in so-called "fire and
extended coverage" form insuring Tenant against loss from physical damage to
Tenant's personal property, inventory, trade fixtures and improvements within
the Leased Premises with coverage for the full actual replacement cost thereof;

            (iii) Plate glass insurance, at actual replacement cost;

            (iv) Pressure vessel insurance, if applicable;

            (v) Workers' compensation insurance and any other employee benefit
insurance sufficient to comply with all laws; and

            (vi) With respect to making of alterations or the construction of
improvements or the like undertaken by Tenant, contingent liability and
builder's risk insurance, in an amount and with coverage reasonably satisfactory
to Landlord.

      (b) Each policy of liability insurance required to be carried by Tenant
pursuant to this paragraph or actually carried by Tenant with respect to the
Leased Premises or the Property: (i) shall, except with respect to insurance
required by subparagraph (a)(vi) above, name Landlord, and such others as are
designated by Landlord, as additional insureds; (ii) shall be primary insurance
providing that the insurer shall be liable for the full amount of the loss, up
to and including the total amount of liability set forth in the declaration of
coverage, without the right of contribution from or prior payment by any other
insurance coverage of Landlord; (iii) shall be in a form satisfactory to
Landlord; (iv) shall be carried with companies reasonably acceptable to Landlord
with Best's ratings of at least A and XI; (v) shall provide that such policy
shall not be subject to cancellation, lapse or change except after at least
thirty days prior written notice to Landlord, and (vi) shall contain a so-called
"severability" or "cross liability" endorsement. Each policy of property
insurance maintained by Tenant with respect to the Leased Premises or the
Property or any property therein (i) shall provide that such policy shall not be
subject to cancellation, lapse or change except after at least thirty days prior
written notice to Landlord and (ii) shall contain a waiver and/or a permission
to waive by the insurer of any right of subrogation against Landlord, its
partners, principals, members, officers, employees, agents and contractors,
which might arise by reason of any payment under such policy or by reason of any
act or omission of Landlord, its partners, principals, members, officers,
employees, agents and contractors.

      (c) Prior to the time Tenant or any of its contractors enters the Leased
Premises, Tenant shall deliver to Landlord, with respect to each policy of
insurance required to be carried by Tenant pursuant to this Article, a copy of
such policy (appropriately authenticated by the insurer as having been issued,
premium paid) or a certificate of the insurer certifying in form satisfactory to
Landlord that a policy has been issued, premium paid, providing the coverage
required by this Paragraph and containing the provisions specified herein. With
respect to each renewal or replacement of any such insurance, the requirements
of this Paragraph must be complied with not less than thirty days prior to the
expiration or cancellation of the policies being renewed or replaced. Landlord
may, at any time and from time to time, inspect and/or copy any and all
insurance policies required to be carried by Tenant pursuant to this Article. If
Landlord's Lender, insurance broker, advisor or counsel reasonably determines at
any time that the amount of coverage set forth in Paragraph 9.1(a) for any
policy of insurance Tenant is required to carry pursuant to this Article is not
adequate, then Tenant shall increase the amount of coverage for such insurance
to such greater amount as Landlord's Lender, insurance broker, advisor or
counsel reasonably deems adequate.

9.2 LANDLORD'S INSURANCE. With respect to insurance maintained by Landlord:

                                       15
<PAGE>

      (a) Landlord shall maintain, as the minimum coverage required of it by
this Lease, fire and property damage insurance in so-called "fire and extended
coverage" form insuring Landlord (and such others as Landlord may designate)
against loss from physical damage to the Building with coverage of not less than
one hundred percent (100%) of the full actual replacement cost thereof and
against loss of rents for a period of not less than six months. Such fire and
property damage insurance, at Landlord's election but without any requirements
on Landlord's behalf to do so, (i) may be written in so-called "all risk" form,
excluding only those perils commonly excluded from such coverage by Landlord's
then property damage insurer; (ii) may provide coverage for physical damage to
the improvements so insured for up to the entire full actual replacement cost
thereof; (iii) may be endorsed to cover loss or damage caused by any additional
perils against which Landlord may elect to insure, including earthquake and/or
flood; and/or (iv) may provide coverage for loss of rents for a period of up to
twelve months. Landlord shall not be required to cause such insurance to cover
any of Tenant's personal property, inventory, and trade fixtures, or any
modifications, alterations or improvements made or constructed by Tenant to or
within the Leased Premises. Landlord shall use commercially reasonable efforts
to obtain such insurance at competitive rates.

      (b) Landlord shall maintain comprehensive general liability insurance
insuring Landlord (and such others as are designated by Landlord) against
liability for personal injury, bodily injury, death, and damage to property
occurring in, on or about, or resulting from the use or occupancy of the
Property, or any portion thereof, with combined single limit coverage of at
least Three Million Dollars ($3,000,000). Landlord may carry such greater
coverage as Landlord or Landlord's Lender, insurance broker, advisor or counsel
may from time to time determine is reasonably necessary for the adequate
protection of Landlord and the Property.

      (c) Landlord may maintain any other insurance which in the opinion of its
insurance broker, advisor or legal counsel is prudent in carry under the given
circumstances, provided such insurance is commonly carried by owners of property
similarly situated and operating under similar circumstances.

9.3 MUTUAL WAIVER OF SUBROGATION. Landlord hereby releases Tenant, and Tenant
hereby releases Landlord and its respective partners, principals, members,
officers, agents, employees and servants, from any and all liability for loss,
damage or injury to the property of the other in or about the Leased Premises or
the Property which is caused by or results from a peril or event or happening
which is covered by insurance actually carried and in force at the time of the
loss by the party sustaining such loss; provided, however, that such waiver
shall be effective only to the extent permitted by the insurance covering such
loss and to the extent such insurance is not prejudiced thereby.

                                   ARTICLE 10

                            DAMAGE TO LEASED PREMISES

10.1 LANDLORD'S DUTY TO RESTORE. If the Leased Premises, the Building or the
Outside Area are damaged by any peril after the Effective Date of this Lease,
Landlord shall restore the same, as and when required by this paragraph, unless
this Lease is terminated by Landlord pursuant to Paragraph 10.3 or by Tenant
pursuant to Paragraph 10.4. If this Lease is not so terminated, then upon the
issuance of all necessary governmental permits, Landlord shall commence and
diligently prosecute to completion the restoration of the Leased Premises, the
Building or the Outside Area, as the case may be, to the extent then allowed by
law, to substantially the same condition in which it existed as of the Lease
Commencement Date. Landlord's obligation to restore shall be limited to the
improvements constructed by Landlord. Landlord shall have no obligation to
restore any Improvements made by Tenant to the Leased Premises or any of
Tenant's personal property, inventory or trade fixtures. Upon completion of the
restoration by Landlord, Tenant shall forthwith replace or fully repair all of
Tenant's personal property, inventory, trade fixtures and other improvements
constructed by Tenant to like or similar conditions as existed at the time
immediately prior to such damage or destruction.

10.2 INSURANCE PROCEEDS. All insurance proceeds available from the fire and
property damage insurance carried by Landlord shall be paid to and become the
property of Landlord. If this Lease is terminated pursuant to either Paragraph
10.3 or 10.4, all insurance proceeds available from insurance carried by Tenant
which cover loss of property that is Landlord's property or would become
Landlord's property on termination of this Lease shall be paid to and become the
property of Landlord, and the remainder of such proceeds shall be paid to and
become the property of Tenant. If this Lease is not terminated pursuant to
either Paragraph 10.3 or 10.4, all insurance proceeds available from insurance
carried by Tenant which cover loss to property that is Landlord's property shall
be paid to and become the property of Landlord, and all proceeds available from
such insurance which cover loss to property which would only become the property
of Landlord upon the termination of this Lease shall be paid to and remain the
property of Tenant. The determination of Landlord's property and Tenant's
property shall be made pursuant to Paragraph 6.2.

10.3 LANDLORD'S RIGHT TO TERMINATE. Landlord shall have the option to terminate
this Lease in the event any of the following occurs, which option may be
exercised only by delivery to Tenant of a written notice of election to
terminate within thirty days after the date of such damage or destruction:

      (a) The Building is damaged by any peril covered by valid and collectible
insurance actually carried by Landlord and in force at the time of such damage
or destruction or by any peril which would have been covered by the insurance
Landlord is required to maintain pursuant to Section 9.2 (an "Insured Peril") to
such an extent that the

                                       16
<PAGE>

estimated cost to restore the Building exceeds the lesser of (i) the insurance
proceeds available from insurance actually carried by Landlord (or which
Landlord was required to carry pursuant to Section 9.2(a) hereof) plus the
amount of any deductible (up to a maximum amount of five percent (5%) of the
replacement cost of the Building), plus any amount that the Tenant agrees in
writing to contribute towards restoration, or (ii) fifty percent of the then
actual replacement cost of the Building;

      (b) The Building is damaged by an uninsured peril, which peril Landlord
was not required to insure against pursuant to the provisions of Article 9 of
this Lease, provided, however, that, subject to the requirements of the holder
of any deed of trust encumbering the Property, Landlord shall not have the right
to terminate this Lease if Tenant notifies Landlord, within thirty (30) days
after Tenant receives Landlord's written notice of termination pursuant to this
Section 10.3, that Tenant will pay for the cost of restoration of the Leased
Premises, in excess of any insurance proceeds to be received by Landlord.

      (c) The Building is damaged by any peril and, because of the laws then in
force, the Building (i) cannot be restored at reasonable cost or (ii) if
restored, cannot be used for the same use being made thereof before such damage.

10.4 TENANT'S RIGHT TO TERMINATE. If the Leased Premises, the Building or the
Outside Area are damaged by any peril and Landlord does not elect to terminate
this Lease or is not entitled to terminate this Lease pursuant to this Article,
then as soon as reasonably practicable, Landlord shall furnish Tenant with the
written opinion of Landlord's architect or construction consultant as to when
the restoration work required of Landlord may be complete. Tenant shall have the
option to terminate this Lease in the event any of the following occurs, which
option may be exercised only by delivery to Landlord of a written notice of
election to terminate within seven days after Tenant receives from Landlord the
estimate of the time needed to complete such restoration:

      (a) If the time estimated to substantially complete the restoration
exceeds nine (9) months from and after the date the architect's or construction
consultant's written opinion is delivered; or

      (b) If the damage occurred within twelve months of the last day of the
Lease Term and the time estimated to substantially complete the restoration
exceeds one hundred eighty days from and after the date such restoration is
commenced.

10.5 TENANT'S WAIVER. Landlord and Tenant agree that the provisions of Paragraph
10.4 above, captioned "Tenant's Right To Terminate", are intended to supersede
and replace the provisions contained in California Civil Code, Section 1932,
Subdivision 2, and California Civil Code, Section 1934, and accordingly, Tenant
hereby waives the provisions of such Civil Code Sections and the provisions of
any successor Civil Code Sections or similar laws hereinafter enacted.

10.6 ABATEMENT OF RENT. In the event of damage to the Leased Premises which does
not result in the termination of this Lease, the Base Monthly Rent (and any
Additional Rent) shall be temporarily abated during the period of restoration in
proportion in the degree to which Tenant's use of the Leased Premises is
impaired by such damage.

                                   ARTICLE 11

                                  CONDEMNATION

11.1 TENANT'S RIGHT TO TERMINATE. Except as otherwise provided in Paragraph 11.4
below regarding temporary takings, Tenant shall have the option to terminate
this Lease if, as a result of any taking, (i) all of the Leased Premises is
taken, or (ii) twenty-five percent (25%) or more of the Leased Premises is taken
and the part of the Leased Premises that remains cannot, within a reasonable
period of time, be made reasonably suitable for the continued operation of
Tenant's business, or (iii) or a portion of the Outside Area is taken such that
the parking available to Tenant is reduced by more than twenty percent (20%),
and the Landlord does not, within a reasonable period of time, provide
alternative parking arrangements within a reasonable walking distance of the
Leased Premises. Tenant must exercise such option within a reasonable period of
time, to be effective on the later to occur of (i) the date that possession of
that portion of the Leased Premises that is condemned is taken by the condemnor
or (ii) the date Tenant vacated the Leased Premises.

11.2 LANDLORD'S RIGHT TO TERMINATE. Except as otherwise provided in Paragraph
11.4 below regarding temporary takings, Landlord shall have the option to
terminate this Lease if, as a result of any taking, (i) all of the Leased
Premises is taken, (ii) twenty-five percent (25%) or more of the Leased Premises
is taken and the part of the Leased Premises that remains cannot, within a
reasonable period of time, be made reasonably suitable for the continued
operation of Tenant's business, or (iii) because of the laws then in force, the
Leased Premises may not be used for the same use being made before such taking,
whether or not restored as required by Paragraph 11.3 below. Any such option to
terminate by Landlord must be exercised within a reasonable period of time, to
be effective as of the date possession is taken by the condemnor.

11.3 RESTORATION. If any part of the Leased Premises or the Building is taken
and this Lease is not terminated, then Landlord shall, to the extent not
prohibited by laws then in force, repair any

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occasioned thereby to the remainder thereof to a condition reasonably suitable
for Tenant's continued operations and otherwise, to the extent practicable, in
the manner and to the extent provided in Paragraph 10.1.

11.4 TEMPORARY TAKING. If a portion of the Leased Premises is temporarily taken
for a period of one year or less and such period does not extend beyond the
Lease Expiration Date, this Lease shall remain in effect. If any portion of the
Leased Premises is temporarily taken for a period which exceeds one year or
which extends beyond the Lease Expiration Date, then the rights of Landlord and
Tenant shall be determined in accordance with Paragraphs 11.1 and 11.2 above.

11.5 DIVISION OF CONDEMNATION AWARD. Any award made for any taking of the
Property, the Building, or the Leased Premises, or any portion thereof, shall
belong to and be paid to Landlord, and Tenant hereby assigns to Landlord all of
its right, title and interest in any such award; provided, however, that Tenant
shall be entitled to receive any portion of the award that is made specifically
(i) for the taking of personal property, inventory or trade fixtures belonging
to Tenant, (ii) for the interruption of Tenant's business or its moving costs,
or (iii) for the value of any leasehold improvements installed and paid for by
Tenant. The rights of Landlord and Tenant regarding any condemnation shall be
determined as provided in this Article, and each party hereby waives the
provisions of Section 1265.130 of the California Code of Civil Procedure, and
the provisions of any similar law hereinafter enacted, allowing either party to
petition the Supreme Court to terminate this Lease and/or otherwise allocate
condemnation awards between Landlord and Tenant in the event of a taking of the
Leased Premises.

11.6 ABATEMENT OF RENT. In the event of a taking of the Leased Premises which
does not result in a termination of this Lease (other than a temporary taking),
then, as of the date possession is taken by the condemning authority, the Base
Monthly Rent shall be reduced in the same proportion that the area of that part
of the Leased Premises so taken (less any addition to the area of the Leased
Premises by reason of any reconstruction) bears to the area of the Leased
Premises immediately prior to such taking.

11.7 TAKING DEFINED. The term "taking" or "taken" as used in this Article 11
shall mean any transfer or conveyance of all or any portion of the Property to a
public or quasi-public agency or other entity having the power of eminent domain
pursuant to or as a result of the exercise of such power by such an agency,
including any inverse condemnation and/or any sale or transfer by Landlord of
all or any portion of the Property to such an agency under threat of
condemnation or the exercise of such power.

                                   ARTICLE 12

                              DEFAULT AND REMEDIES

12.1 EVENTS OF TENANT'S DEFAULT. Tenant shall be in default of its obligations
under this Lease if any of the following events occur:

      (a) Tenant shall have failed to pay Base Monthly Rent or any Additional
Rent within three (3) days after notice from Landlord that such rent is past due
provided, however, that such notice shall be concurrent with, and not in
addition to, any notice required by applicable Laws; or

      (b) Tenant shall have done or permitted to be done any act, use or thing
in its use, occupancy or possession of the Leased Premises or the Building or
the Outside Areas which is prohibited by the terms of this Lease or Tenant shall
have failed to perform any term, covenant or condition of this Lease (except
those requiring the payment of Base Monthly Rent or Additional Rent, which
failures shall be governed by subparagraph (a) above) within thirty (30) days
after written notice from Landlord to Tenant specifying the nature of such
failure and requesting Tenant to perform same or within such longer period as is
reasonably required in the event such default is curable but not within such
thirty (30) day period, provided such cure is promptly commenced within such
thirty (30) day period and is thereafter diligently prosecuted to completion; or

      (c) Tenant shall have sublet the Leased Premises or assigned or encumbered
its interest in this Lease in violation of the provisions contained in Article
7, whether voluntarily or by operation of law; or

      (d) Tenant shall have abandoned the Leased Premises; or

      (e) Tenant or any Guarantor of this Lease shall have permitted or suffered
the sequestration or attachment of, or execution on, or the appointment of a
custodian or receiver with respect to, all or any substantial part of the
property or assets of Tenant (or such Guarantor) or any property or asset
essential to the conduct of Tenant's (or such Guarantor's) business, and Tenant
(or such Guarantor) shall have failed to obtain a return or release of the same
within thirty days thereafter, or prior to sale pursuant to such sequestration,
attachment or levy, whichever is earlier; or

      (f) Tenant or any Guarantor of this Lease shall have made a general
assignment of all or a substantial part of its assets for the benefit of its
creditors; or

      (g) Tenant or any Guarantor of this Lease shall have allowed (or sought)
to have entered against it a decree or order which: (i) grants or constitutes an
order for relief, appointment of a trustee, or condemnation or a reorganization
plan under the bankruptcy laws of the United States; (ii) approves as properly
filed a petition seeking

                                       18
<PAGE>

liquidation or reorganization under said bankruptcy laws or any other debtor's
relief law or similar statute of the United States or any state thereof; or
(iii) otherwise directs the winding up or liquidation of Tenant; provided,
however, if any decree or order was entered without Tenant's consent or over
Tenant's objection, Landlord may not terminate this Lease pursuant to this
Subparagraph if such decree or order is rescinded or reversed within thirty days
after its original entry; or

      (h) Tenant or any Guarantor of this Lease shall have availed itself of the
protection of any debtor's relief law, moratorium law or other similar law which
does not require the prior entry of a decree or order.

      (i) Tenant shall be in default of its obligations under any Lease between
Mathilda Associates LLC and Tenant.

12.2 LANDLORD'S REMEDIES. In the event of any default by Tenant, and without
limiting Landlord's right to indemnification as provided in Article 8.2,
Landlord shall have the following remedies, in addition to all other rights and
remedies provided by law or otherwise provided in this Lease, to which Landlord
may resort cumulatively, or in the alternative:

      (a) Landlord may, at Landlord's election, keep this Lease in effect and
enforce, by an action at law or in equity, all of its rights and remedies under
this Lease including, without limitation, (i) the right to recover the rent and
other sums as they become due by appropriate legal action, (ii) the right to
make payments required by Tenant, or perform Tenant's obligations and be
reimbursed by Tenant for the cost thereof with interest at the then maximum rate
of interest not prohibited by law from the date the sum is paid by Landlord
until Landlord is reimbursed by Tenant, and (iii) the remedies of injunctive
relief and specific performance to prevent Tenant from violating the terms of
this Lease and/or to compel Tenant to perform its obligations under this Lease,
as the case may be.

      (b) Landlord may, at Landlord's election, terminate this Lease by giving
Tenant written notice of termination, in which event this Lease shall terminate
on the date set forth for termination in such notice, in which event Tenant
shall immediately surrender the Leased Premises to Landlord, and if Tenant fails
to do so, Landlord may, without prejudice to any other remedy which it may have
for possession or arrearages in rent, enter upon and take possession of the
Leased Premises and expel or remove Tenant and any other person who may be
occupying the Leased Premises or any part thereof, without being liable for
prosecution or any claim or damages therefor. Any termination under this
subparagraph shall not relieve Tenant from its obligation to pay to Landlord all
Base Monthly Rent and Additional Rent then or thereafter due, or any other sums
due or thereafter accruing to Landlord, or from any claim against Tenant for
damages previously accrued or then or thereafter accruing. In no event shall any
one or more of the following actions by Landlord, in the absence of a written
election by Landlord to terminate this Lease constitute a termination of this
Lease:

            (i) Appointment of a receiver or keeper in order to protect
Landlord's interest hereunder;

            (ii) Consent to any subletting of the Leased Premises or assignment
of this Lease by Tenant, whether pursuant to the provisions hereof or otherwise;
or

            (iii) Any action taken by Landlord or its partners, principals,
members, officers, agents, employees, or servants, which is intended to mitigate
the adverse effects of any breach of this Lease by Tenant, including, without
limitation, any action taken to maintain and preserve the Leased Premises on any
action taken to relet the Leased Premises or any portion thereof for the account
at Tenant and in the name of Tenant.

      (c) In the event Tenant breaches this Lease and abandons the Leased
Premises, Landlord may terminate this Lease, but this Lease shall not terminate
unless Landlord gives Tenant written notice of termination. If Landlord does not
terminate this Lease by giving written notice of termination, Landlord may
enforce all its rights and remedies under this Lease, including the right and
remedies provided by California Civil Code Section 1951.4 ("lessor may continue
lease in effect after lessee's breach and abandonment and recover rent as it
becomes due, if lessee has right to sublet or assign, subject only to reasonable
limitations"), as in effect on the Effective Date of this Lease.

      (d) In the event Landlord terminates this Lease, Landlord shall be
entitled, at Landlord's election, to the rights and remedies provided in
California Civil Code Section 1951.2, as in effect on the Effective Date of this
Lease. For purposes of computing damages pursuant to Section 1951.2, an interest
rate equal to the maximum rate of interest then not prohibited by law shall be
used where permitted. Such damages shall include, without limitation:

            (i) The worth at the time of the award of the unpaid rent which had
been earned at the time of termination;

            (ii) The worth at the time of award of the amount by which the
unpaid rent for the balance of the term after the time of award exceeds the
amount of such rental loss that Tenant proves could be reasonably avoided,
computed by discounting such amount at the discount rate of the Federal Reserve
Bank of San Francisco, at the time of award plus one percent; and

            (iii) Any other amount necessary to compensate Landlord for all
detriment proximately caused by Tenant's failure to perform Tenant's obligations
under this Lease, or which in the ordinary course of things would be likely to
result therefrom, including without limitation, the following: (i) expenses for
cleaning, repairing or restoring the Leased Premises, (ii) expenses for
altering, remodeling or otherwise improving the Leased

                                       19
<PAGE>

Premises for the purpose of reletting, including removal of existing leasehold
improvements and/or installation of additional leasehold improvements
(regardless of how the same is funded, including reduction of rent, a direct
payment or allowance to a new tenant, or otherwise), (iii) broker's fees
allocable to the remainder of the term of this Lease, advertising costs and
other expenses of reletting the Leased Premises; (iv) costs of carrying and
maintaining the Leased Premises, such as taxes, insurance premiums, utility
charges and security precautions, (v) expenses incurred in removing, disposing
of and/or storing any of Tenant's personal property, inventory or trade fixtures
remaining therein; (vi) reasonable attorney's fees, expert witness fees, court
costs and other reasonable expenses incurred by Landlord (but not limited to
taxable costs) in retaking possession of the Leased Premises, establishing
damages hereunder, and releasing the Leased Premises; and (vii) any other
expenses, costs or damages otherwise incurred or suffered as a result of
Tenant's default.

12.3 LANDLORD'S DEFAULT AND TENANT'S REMEDIES. In the event Landlord fails to
perform its obligations under this Lease, Landlord shall nevertheless not be in
default under the terms of this Lease until such time as Tenant shall have first
given Landlord written notice specifying the nature of such failure to perform
its obligations, and then only after Landlord shall have had thirty (30) days
following its receipt of such notice within which to perform such obligations;
provided that, if longer than thirty (30) days is reasonably required in order
to perform such obligations, Landlord shall have such longer period. In the
event of Landlord's default as above set forth, then, and only then, Tenant may
then proceed in equity or at law to compel Landlord to perform its obligations
and/or to recover damages proximately caused by such failure to perform (except
as and to the extent Tenant has waived its right to damages as provided in this
Lease).

12.4 LIMITATION OF TENANT'S RECOURSE. If Landlord is a corporation, trust,
partnership, joint venture, limited liability company, unincorporated
association, or other form of business entity, Tenant agrees that (i) the
obligations of Landlord under this Lease shall not constitute personal
obligations of the officers, directors, trustees, partners, joint venturers,
members, owners, stockholders, or other principals of such business entity, and
(ii) Tenant shall have recourse only to the property of such corporation, trust,
partnership, joint venture, limited liability company, unincorporated
association, or other form of business entity for the satisfaction of such
obligations and not against the assets of such officers, directors, trustees,
partners, joint venturers, members, owners, stockholders or principals.
Additionally, if Landlord is a partnership or limited liability company, then
Tenant covenants and agrees:

      (a) No partner or member of Landlord shall be sued or named as a party in
any suit or action brought by Tenant with respect to any alleged breach of this
Lease (except to the extent necessary to secure jurisdiction over the
partnership and then only for that sole purpose);

      (b) No service of process shall be made against any partner or member of
Landlord except for the sole purpose of securing jurisdiction over the
partnership; and

      (c) No writ of execution will ever be levied against the assets of any
partner or member of Landlord other than to the extent of his or her interest in
the assets of the partnership or limited liability company constituting
Landlord.

Tenant further agrees that each of the foregoing covenants and agreements shall
be enforceable by Landlord and by any partner or member of Landlord and shall be
applicable to any actual or alleged misrepresentation or nondisclosure made
regarding this Lease or the Leased Premises or any actual or alleged failure,
default or breach of any covenant or agreement either expressly or implicitly
contained in this Lease or imposed by statute or at common law.

12.5 TENANT'S WAIVER. Landlord and Tenant agree that the provisions of Paragraph
12.3 above are intended to supersede and replace the provisions of California
Civil Code Sections 1932(1), 1941 and 1942, and accordingly, Tenant hereby
waives the provisions of California Civil Code Sections 1932(1), 1941 and 1942
and/or any similar or successor law regarding Tenant's right to terminate this
Lease or to make repairs and deduct the expenses of such repairs from the rent
due under this Lease.

                                   ARTICLE 13

                               GENERAL PROVISIONS

13.1 TAXES ON TENANT'S PROPERTY. Tenant shall pay before delinquency any and all
taxes, assessments, license fees, use fees, permit fees and public charges of
whatever nature or description levied, assessed or imposed against Tenant or
Landlord by a governmental agency arising out of, caused by reason of or based
upon Tenant's estate in this Lease, Tenant's ownership of property, improvements
made by Tenant to the Leased Premises or the Outside Areas, improvements made by
Landlord for Tenant's use within the Leased Premises or the Outside Areas,
Tenant's use (or estimated use) of public facilities or services or Tenant's
consumption (or estimated consumption) of public utilities, energy, water or
other resources (collectively, "Tenant's Interest"). Upon demand by Landlord,
Tenant shall furnish Landlord with satisfactory evidence of these payments. If
any such taxes, assessments, fees or public charges are levied against Landlord,
Landlord's property, the Building or the Property, or if the assessed value of
the Building or the Property is increased by the inclusion therein of a value
placed upon Tenant's Interest, regardless of the validity thereof, Landlord
shall have the right to require Tenant to pay such taxes, and if not paid and
satisfactory evidence of payment delivered to Landlord at least ten days prior
to delinquency, then Landlord shall have the right to pay such taxes on Tenant's
behalf and to invoice Tenant for the same. Tenant shall, within the earlier to
occur of (a) thirty (30) days of the date it receives an invoice

                                       20
<PAGE>

from Landlord setting forth the amount of such taxes, assessments, fees, or
public charge so levied, or (b) the due date of such invoice, pay to Landlord,
as Additional Rent, the amount set forth in such invoice. Failure by Tenant to
pay the amount so invoiced within such time period shall be conclusively deemed
a default by Tenant under this Lease. Tenant shall have the right to bring suit
in any court of competent jurisdiction to recover from the taxing authority the
amount of any such taxes, assessments, fees or public charges so paid.

13.2 HOLDING OVER. This Lease shall terminate without further notice on the
Lease Expiration Date (as set forth in Article 1). Any holding over by Tenant
after expiration of the Lease Term shall neither constitute a renewal nor
extension of this Lease nor give Tenant any rights in or to the Leased Premises
except as expressly provided in this Paragraph. Any such holding over to which
Landlord has consented shall be construed to be a tenancy from month to month,
on the same terms and conditions herein specified insofar as applicable, except
that the Base Monthly Rent shall be increased to an amount equal to one hundred
fifty percent (150%) of the Base Monthly Rent payable during the last full month
immediately preceding such holding over. Tenant acknowledges that if Tenant
holds over without Landlord's consent, such holding over may compromise or
otherwise affect Landlord's ability to enter into new leases with prospective
tenants regarding the Leased Premises. Therefore, if Tenant fails to surrender
the Leased Premises upon the expiration or termination of this Lease, in
addition to any other liabilities to Landlord accruing therefrom, Tenant shall
protect, defend, indemnify and hold Landlord harmless from and against all
claims resulting from such failure, including, without limiting the foregoing,
any claims made by any succeeding tenant founded upon such failure to surrender,
and any losses suffered by Landlord, including lost profits, resulting from such
failure to surrender.

13.3 SUBORDINATION TO MORTGAGES. This Lease is subject to and subordinate to all
ground leases, mortgages and deeds of trust which affect the Building or the
Property and which are of public record as of the Effective Date of this Lease,
and to all renewals, modifications, consolidations, replacements and extensions
thereof. However, if the lessor under any such ground lease or any lender
holding any such mortgage or deed of trust shall advise Landlord that it desires
or requires this Lease to be made prior and superior thereto, then, upon written
request of Landlord to Tenant, Tenant shall promptly execute, acknowledge and
deliver any and all customary or reasonable documents or instruments which
Landlord and such lessor or lender deems necessary or desirable to make this
Lease prior thereto. Tenant hereby consents to Landlord's ground leasing the
land underlying the Building or the Property and/or encumbering the Building or
the Property as security for future loans on such terms as Landlord shall
desire, all of which future ground leases, mortgages or deeds of trust shall be
subject to and subordinate to this Lease. However, if any lessor under any such
future ground lease or any lender holding such future mortgage or deed of trust
shall desire or require that this Lease be made subject to and subordinate to
such future ground lease, mortgage or deed of trust, then Tenant agrees, within
ten (10) days after Landlord's written request therefor, to execute, acknowledge
and deliver to Landlord any and all documents or instruments reasonably
requested by Landlord or by such lessor or lender as may be necessary or proper
to assure the subordination of this Lease to such future ground lease, mortgage
or deed of trust, but only if such lessor or lender agrees to recognize Tenant's
rights under this Lease and agrees not to disturb Tenant's quiet possession of
the Leased Premises so long as Tenant is not in default under this Lease. If
Landlord assigns the Lease as security for a loan, Tenant agrees to execute such
documents as are reasonably requested by the lender and to provide reasonable
provisions in the Lease protecting such lender's security interest which are
customarily required by institutional lenders making loans secured by a deed of
trust provided that such documents do not materially increase Tenant's
obligations under this Lease.

13.4 TENANT'S ATTORNMENT UPON FORECLOSURE. Tenant shall, upon request, attorn
(i) to any purchaser of the Building or the Property at any foreclosure sale or
private sale conducted pursuant to any security instruments encumbering the
Building or the Property, (ii) to any grantee or transferee designated in any
deed given in lieu of foreclosure of any security interest encumbering the
Building or the Property, or (iii) to the lessor under an underlying ground
lease of the land underlying the Building or the Property, should such ground
lease be terminated; provided that such purchaser, grantee or lessor recognizes
Tenant's rights under this Lease.

13.5 MORTGAGEE PROTECTION. In the event of any default on the part of Landlord,
Tenant will give notice by registered mail to any Lender or lessor under any
underlying ground lease who shall have requested, in writing, to Tenant that it
be provided with such notice, and Tenant shall offer such Lender or lessor a
reasonable opportunity to cure the default, including time to obtain possession
of the Leased Premises by power of sale or judicial foreclosure or other
appropriate legal proceedings if reasonably necessary to effect a cure.

13.6 ESTOPPEL CERTIFICATE. Tenant will, following any request by Landlord,
promptly execute and deliver to Landlord an estoppel certificate substantially
in form attached as Exhibit B, (i) certifying that this Lease is unmodified and
in full force and effect, or, if modified, stating the nature of such
modification and certifying that this Lease, as so modified, is in full force
and effect, (ii) stating the date to which the rent and other charges are paid
in advance, if any, (iii) acknowledging that there are not, to Tenant's
knowledge, any uncured defaults on the part of Landlord hereunder, or specifying
such defaults if any are claimed, and (iv) certifying such other information
about this Lease as may be reasonably requested by Landlord, its Lender or
prospective lenders, investors or purchasers of the Building or the Property.
Tenant's failure to execute and deliver such estoppel certificate within ten
days after Landlord's request therefor shall be a material default by Tenant
under this Lease, and Landlord shall have all of the rights and remedies
available to Landlord as Landlord would otherwise have in the case of any other
material default by Tenant, including the right to terminate this Lease and sue
for damages proximately caused thereby, it being agreed and understood by Tenant
that Tenant's failure to so deliver such estoppel certificate in a timely manner
could result in Landlord being unable to perform committed obligations to other
third parties which were made by Landlord in reliance upon this covenant of
Tenant. Landlord and Tenant intend that any statement delivered pursuant to this
paragraph may be relied upon by any Lender or purchaser or prospective Lender or
purchaser of the Building, the Property, or any interest in them.

                                       21
<PAGE>

13.7 TENANT'S FINANCIAL INFORMATION. Tenant shall, within ten business days
after Landlord's request therefor, deliver to Landlord a copy of Tenant's (and
any guarantor's) current financial statements (including a balance sheet, income
statement and statement of cash flow, all prepared in accordance with generally
accepted accounting principles) and any such other information reasonably
requested by Landlord regarding Tenant's financial condition. Landlord shall be
entitled to disclose such financial statements or other information to its
Lender, to any present or prospective principal of or investor in Landlord, or
to any prospective Lender or purchaser of the Building, the Property, or any
portion thereof or interest therein. Any such financial statement or other
information which is marked "confidential" or "company secrets" (or is otherwise
similarly marked by Tenant) shall be confidential and shall not be disclosed by
Landlord to any third party except as specifically provided in this paragraph
and then only if the person to whom disclosure is made first agrees to be bound
by the requirements of this Section 13.7, unless the same becomes a part of the
public domain without the fault of Landlord.

13.8 TRANSFER BY LANDLORD. Landlord and its successors in interest shall have
the right to transfer their interest in the Building, the Property, or any
portion thereof at any time and to any person or entity. In the event of any
such transfer, the Landlord originally named herein (and in the case of any
subsequent transfer, the transferor), from the date of such transfer, (i) shall
be automatically relieved, without any further act by any person or entity, of
all liability for the performance of the obligations of the Landlord hereunder
which may accrue after the date of such transfer so long as the Security Deposit
(or the remaining amount of such Security Deposit after deductions made in
accordance with Section 3.7 of this Lease) is transferred to the transferee (or
returned to the Tenant) and the transferee has agreed to assume and perform all
such obligations which may accrue after the date of such transfer and (ii) shall
be relieved of all liability for the performance of the obligations of the
Landlord hereunder which have accrued before the date of transfer if its
transferee agrees to assume and perform all such prior obligations of the
Landlord hereunder. Tenant shall attorn to any such transferee. After the date
of any such transfer, the term "Landlord" as used herein shall mean the
transferee of such interest in the Building or the Property.

13.9 FORCE MAJEURE. The obligations of each of the parties under this Lease
(other than the obligations to pay money) shall be temporarily excused if such
party is prevented or delayed in performing such obligations by reason of any
strikes, lockouts or labor disputes; government restrictions, regulations,
controls, action or inaction; civil commotion; or extraordinary weather, fire or
other acts of God.

13.10 NOTICES. Any notice required or permitted to be given under this Lease
shall be in writing and (i) personally delivered, (ii) sent by United States
mail, registered or certified mail, postage prepaid, return receipt requested,
(iii) sent by Federal Express or similar nationally recognized overnight courier
service, or (iv) transmitted by facsimile with a hard copy sent within one (1)
business day by any of the foregoing means, and in all cases addressed as
follows, and such notice shall be deemed to have been given upon the date of
actual receipt or delivery (or refusal to accept delivery) at the address
specified below (or such other addresses as may be specified by notice in the
foregoing manner) as indicated on the return receipt or air bill:

      IF TO LANDLORD:      Mathilda Associates II LLC
                           c/o Menlo Equities LLC
                           490 California Avenue, 4th Floor
                           Palo Alto, California  94306
                           Attention:  Henry Bullock/Richard Holmstrom

      with a copy to:      Cooley Godward LLP
                           One Maritime Plaza
                           20th Floor
                           San Francisco, California  94111
                           Attention:  Paul Churchill

      with a copy to:      Beacon Capital Partners Inc.
                           One Federal Street, 26th Floor
                           Boston, Massachusetts 02110
                           Attention:  General Counsel

      IF TO TENANT:        Juniper Networks Inc.
                           1194 Mathilda Avenue
                           Sunnyvale, California 94089
                           Attention:  General Counsel

Any notice given in accordance with the foregoing shall be deemed received upon
actual receipt or refusal to accept delivery.

13.11 ATTORNEYS' FEES. In the event any party shall bring any action,
arbitration proceeding or legal proceeding alleging a breach of any provision of
this Lease, to recover rent, to terminate this Lease, or to enforce, protect,
determine or establish any term or covenant of this Lease or rights or duties
hereunder of either party, the prevailing party shall be entitled to recover
from the non-prevailing party as a part of such action or proceeding, or in a
separate action for that purpose brought within one year from the determination
of such proceeding, reasonable attorneys' fees, expert witness fees, court costs
and other reasonable expenses incurred by the prevailing party.

                                       22
<PAGE>

13.12 DEFINITIONS. Any term that is given a special meaning by any provision in
this Lease shall, unless otherwise specifically stated, have such meaning
wherever used in this Lease or in any Addenda or amendment hereto. In addition
to the terms defined in Article 1, the following terms shall have the following
meanings:

      (a) REAL PROPERTY TAXES. The term "Real Property Tax" or "Real Property
Taxes" shall each mean the sum of Tenant's Property Share (as to the land
component of the Property) and Tenant's Expense Share (as to the Building and
other improvements in the Outside Areas) of (i) all taxes, assessments, levies
and other charges of any kind or nature whatsoever, general and special,
foreseen and unforeseen (including all instruments of principal and interest
required to pay any general or special assessments for public improvements and
any increases resulting from reassessments caused by any change in ownership or
new construction), now or hereafter imposed by any governmental or
quasi-governmental authority or special district having the direct or indirect
power to tax or levy assessments, which are levied or assessed for whatever
reason against the Property or any portion thereof, or Landlord's interest
herein, or the fixtures, equipment and other property of Landlord that is an
integral part of the Property and located thereon, or Landlord's business of
owning, leasing or managing the Property or the gross receipts, income or
rentals from the Property, (ii) all charges, levies or fees imposed by any
governmental authority against Landlord by reason of or based upon the use of or
number of parking spaces within the Property, the amount of public services or
public utilities used or consumed (e.g. water, gas, electricity, sewage or waste
water disposal) at the Property, the number of person employed by tenants of the
Property, the size (whether measured in area, volume, number of tenants or
whatever) or the value of the Property, or the type of use or uses conducted
within the Property, and all costs and fees (including attorneys' fees)
reasonably incurred by Landlord in contesting any Real Property Tax and in
negotiating with public authorities as to any Real Property Tax. If, at any time
during the Lease Term, the taxation or assessment of the Property prevailing as
of the Effective Date of this Lease shall be altered so that in lieu of or in
addition to any the Real Property Tax described above there shall be levied,
awarded or imposed (whether by reason of a change in the method of taxation or
assessment, creation of a new tax or charge, or any other cause) an alternate,
substitute, or additional use or charge (i) on the value, size, use or occupancy
of the Property or Landlord's interest therein or (ii) on or measured by the
gross receipts, income or rentals from the Property, or on Landlord's business
of owning, leasing or managing the Property or (iii) computed in any manner with
respect to the operation of the Property, then any such tax or charge, however
designated, shall be included within the meaning of the terms "Real Property
Tax" or "Real Property Taxes" for purposes of this Lease. If any Real Property
Tax is partly based upon property or rents unrelated to the Property, then only
that part of such Real Property Tax that is fairly allocable to the Property
shall be included within the meaning of the terms "Real Property Tax" or "Real
Property Taxes." Notwithstanding the foregoing, the terms "Real Property Tax" or
"Real Property Taxes" shall not include estate, inheritance, transfer, gift or
franchise taxes of Landlord or the federal or state income tax imposed on
Landlord's income from all sources.

      (b) LANDLORD'S INSURANCE COSTS. The term "Landlord's Insurance Costs"
shall mean Tenant's Expense Share of the costs to Landlord to carry and maintain
the policies of fire and property damage insurance for the Building and Tenant's
Property Share of the costs to Landlord to carry and maintain the policies of
fire and property damage insurance on the Property and general liability and any
other insurance required or permitted to be carried by Landlord pursuant to
Article 9, together with any deductible amounts paid by Landlord upon the
occurrence of any insured casualty or loss. Any deductible amount in excess
of twenty five (25%) of the total casualty shall be amortized over the useful
life of the repair or replacement required to restore the Property after such
casualty, and the amortized portion shall be included on a monthly basis in
Landlord's Insurance Costs. Notwithstanding the foregoing, if Tenant terminates
this Lease pursuant to Section 10.4 hereof, Tenant shall not be required to pay
for any insurance deductibles as part of Landlord's Insurance Costs or
otherwise.

      (c) PROPERTY MAINTENANCE COSTS. The term "Property Maintenance Costs"
shall mean Tenant's Property Share of all costs and expenses (except Landlord's
Insurance Costs and Real Property Taxes) paid or incurred by Landlord in
protecting, operating, maintaining, repairing and preserving the Property and
all parts thereof, including without limitation, (i) market rate professional
management fees of no more than two percent (2%) of Base Monthly Rent, (ii) the
amortizing portion of any costs incurred by Landlord in the making of any
modifications, alterations or improvements required by any governmental
authority as set forth in Article 6, which are so amortized during the Lease
Term, (iii) any and all on-going operation or maintenance costs imposed on the
Property by or through any development agreement, use permit, site development
agreement, traffic mitigation plan, entitlement, or Private Restrictions
(including but not limited to shuttle and emergency transportation), and (iv)
such other costs as may be paid or incurred with respect to operating,
maintaining, and preserving the Property, repairing and resurfacing paved areas,
and repairing and replacing, when necessary, electrical, plumbing, heating,
ventilating and air conditioning systems serving the Building, provided that the
cost of any capital improvement shall be amortized over the useful life of such
improvement and the amortizing portion of the cost shall be included in Property
Maintenance Costs. If any costs and expenses are partly based upon property or
rents unrelated to the Property, then only that part of such Property
Maintenance Costs that is fairly allocable to the Property shall be included
within the meaning of the terms "Property Maintenance Costs." Notwithstanding
the foregoing provisions of this Section 13.12(c), the following are
specifically excluded from the definition of Property Maintenance Costs and
Tenant shall have no obligation to pay directly or reimburse Landlord for all or
any portion of the following except to the extent any of the foregoing are
caused by the actions or inactions of Tenant, or result from the failure of
Tenant to comply with the terms of the Lease: (a) costs of development or
construction on the Property (other than on-going operation or maintenance costs
as set forth in (iii) above); (b) the costs to repair or replace the structural
portions of the Building or other buildings on the Property, including, without
limitation, the foundation, footings, roof structure, roof screens, roof screen
penetrations, and load bearing and exterior walls of the Building or any other
building located on the Property; (c) depreciation, amortization or other
expense reserves; (d) interest, charges and fees incurred on debt, payments on
mortgages and rent under ground leases; (e) costs and expenses for which Tenant
reimburses Landlord directly or which Tenant pays directly to a

                                       23
<PAGE>

third person or costs for which Landlord has a right of reimbursement from
others; (f) costs occasioned by the active negligence or willful misconduct of
Landlord or any other occupant of the Property or violations of Law by Landlord
or any other occupant of the Property, (g) or costs to correct any construction
defect in the Leased Premises, the Building or the Property; or (h) capital
costs incurred to bring the Building or the Property into compliance with the
Use Permit, any CC&R's, underwriter's requirements, or Laws applicable to the
Leased Premises, the Building or the Property at the time the building permit
for the Base Building (as defined in the Work Letter) is issued.

      (d) PROPERTY OPERATING EXPENSES. The term "Property Operating Expenses"
shall mean and include all Real Property Taxes, plus all Landlord's Insurance
Costs, plus all Property Maintenance Costs.

      (e) LAW. The term "Law" shall mean any judicial decisions and any statute,
constitution, ordinance, resolution, regulation, rule, administrative order, or
other requirements of any municipal, county, state, federal, or other
governmental agency or authority having jurisdiction over the parties to this
Lease, the Leased Premises, the Building or the Property, or any of them, in
effect either at the Effective Date of this Lease or at any time during the
Lease Term, including, without limitation, any regulation, order, or policy of
any quasi-official entity or body (e.g. a board of fire examiners or a public
utility or special district).

      (f) LENDER. The term "Lender" shall mean the holder of any promissory note
or other evidence of indebtedness secured by the Property or any portion
thereof.

      (g) PRIVATE RESTRICTIONS. The term "Private Restrictions" shall mean (as
they may exist from time to time) any and all covenants, conditions and
restrictions, private agreements, easements, and any other recorded documents or
instruments affecting the use of the Property, the Building, the Leased
Premises, or the Outside Areas.

      (h) RENT. The term "Rent" shall mean collectively Base Monthly Rent and
all Additional Rent.

13.13 GENERAL WAIVERS. One party's consent to or approval of any act by the
other party requiring the first party's consent or approval shall not be deemed
to waive or render unnecessary the first party's consent to or approval of any
subsequent similar act by the other party. No waiver of any provision hereof, or
any waiver of any breach of any provision hereof, shall be effective unless in
writing and signed by the waiving party. The receipt by Landlord of any rent or
payment with or without knowledge of the breach of any other provision hereof
shall not be deemed a waiver of any such breach. No waiver of any provision of
this Lease shall be deemed a continuing waiver unless such waiver specifically
states so in writing and is signed by both Landlord and Tenant. No delay or
omission in the exercise of any right or remedy accruing to either party upon
any breach by the other party under this Lease shall impair such right or remedy
or be construed as a waiver of any such breach theretofore or thereafter
occurring. The waiver by either party of any breach of any provision of this
Lease shall not be deemed to be a waiver of any subsequent breach of the same or
any other provisions herein contained.

13.14 MISCELLANEOUS. Should any provisions of this Lease prove to be invalid or
illegal, such invalidity or illegality shall in no way affect, impair or
invalidate any other provisions hereof, and such remaining provisions shall
remain in full force and effect. Time is of the essence with respect to the
performance of every provision of this Lease in which time of performance is a
factor. Any copy of this Lease which is executed by the parties shall be deemed
an original for all purposes. This Lease shall, subject to the provisions
regarding assignment, apply to and bind the respective heirs, successors,
executors, administrators and assigns of Landlord and Tenant. The term "party"
shall mean Landlord or Tenant as the context implies. If Tenant consists of more
than one person or entity, then all members of Tenant shall be jointly and
severally liable hereunder. This Lease shall be construed and enforced in
accordance with the Laws of the State in which the Leased Premises are located.
The captions in this Lease are for convenience only and shall not be construed
in the construction or interpretation of any provision hereof. When the context
of this Lease requires, the neuter gender includes the masculine, the feminine,
a partnership, corporation, limited liability company, joint venture, or other
form of business entity, and the singular includes the plural. The terms "must,"
"shall," "will," and "agree" are mandatory. The term "may" is permissive. When a
party is required to do something by this Lease, it shall do so at its sole cost
and expense without right of reimbursement from the other party unless specific
provision is made therefor. Where Landlord's consent is required hereunder, the
consent of any Lender shall also be required. Landlord and Tenant shall both be
deemed to have drafted this Lease, and the rule of construction that a document
is to be construed against the drafting party shall not be employed in the
construction or interpretation of this Lease. Where Tenant is obligated not to
perform any act or is not permitted to perform any act, Tenant is also obligated
to restrain any others reasonably within its control, including agents,
invitees, contractors, subcontractors and employees, from performing such act.
Landlord shall not become or be deemed a partner or a joint venturer with Tenant
by reason of any of the provisions of this Lease.

13.15 COOPERATION. Notwithstanding anything to the contrary contained herein,
Tenant consents to and agrees to fully cooperate with Landlord and Landlord's
agents, employees and contractors in Landlord's efforts, if any, to in crease
the floor area ratio approved by the City of Sunnyvale for the Property, to
improve the Property with an additional building and divide the Property into
separate legal parcels, which efforts may include, without limitation, the
elimination of landscaping, the restriping or reconfiguration of the parking
areas, application for building permits and other development approvals,
parcelization of the Property and construction of buildings. Tenant agrees to
execute such documents and take such actions as reasonably necessary to assist
Landlord with such efforts and actions. Tenant agrees that such efforts and
actions of Landlord shall not constitute constructive eviction of Tenant from
the Property or Leased Premises. Following any parcelization of the

                                       24
<PAGE>

Property, Landlord and Tenant agree to amend this Lease to conform the
descriptions of the Property, Site Plan, and Outside Areas, and, subject to
Section 4.5, the parking areas contained herein to the parcelization and
reconfiguration. Landlord agrees to minimize the disruption of Tenant's use of
the Leased Premises, the Building, the Outside Areas and the Property to the
extent reasonable, given Landlord's efforts and actions described herein.

                                   ARTICLE 14

                               CORPORATE AUTHORITY
                          BROKERS AND ENTIRE AGREEMENT

14.1 CORPORATE AUTHORITY. If Tenant is a corporation, each individual executing
this Lease on behalf of such corporation represents and warrants that Tenant is
validly formed and duly authorized and existing, that Tenant is qualified to do
business in the State in which the Leased Premises are located, that Tenant has
the full right and legal authority to enter into this Lease, and that he or she
is duly authorized to execute and deliver this Lease on behalf of Tenant in
accordance with its terms. Tenant shall, within thirty days after execution of
this Lease, deliver to Landlord a certified copy of the resolution of its board
of directors authorizing or ratifying the execution of this Lease and if Tenant
fails to do so, Landlord at its sole election may elect to terminate this Lease.

14.2 BROKERAGE COMMISSIONS. Tenant represents, warrants and agrees that it has
not had any dealings with any real estate broker(s), leasing agent(s), finder(s)
or salesmen, other than the Brokers (as named in Article 1) with respect to the
lease by it of the Leased Premises pursuant to this Lease, and that it will
assume all obligations and responsibility with respect to the payment of such
Brokers, and that it will indemnify, defend with competent counsel, and hold
Landlord harmless from any liability for the payment of any real estate
brokerage commissions, leasing commissions or finder's fees claimed by any other
real estate broker(s), leasing agent(s), finder(s), or salesmen to be earned or
due and payable by reason of Tenant's agreement or promise (implied or
otherwise) to pay (or to have Landlord pay) such a commission or finder's fee by
reason of its leasing the Leased Premises pursuant to this Lease.

14.3 ENTIRE AGREEMENT. This Lease and the Exhibits (as described in Article 1),
which Exhibits are by this reference incorporated herein, constitute the entire
agreement between the parties, and there are no other agreements, understandings
or representations between the parties relating to the lease by Landlord of the
Leased Premises to Tenant, except as expressed herein. No subsequent changes,
modifications or additions to this Lease shall be binding upon the parties
unless in writing and signed by both Landlord and Tenant.

14.4 LANDLORD'S REPRESENTATIONS. Tenant acknowledges that neither Landlord nor
any of its agents made any representations or warranties respecting the
Property, the Building or the Leased Premises, upon which Tenant relied in
entering into the Lease, which are not expressly set forth in this Lease. Tenant
further acknowledges that neither Landlord nor any of its agents made any
representations as to (i) whether the Leased Premises may be used for Tenant's
intended use under existing Law, or (ii) the suitability of the Leased Premises
for the conduct of Tenant's business, or (iii) the exact square footage of the
Leased Premises, and that Tenant relies solely upon its own investigations with
respect to such matters. Tenant expressly waives any and all claims for damage
by reason of any statement, representation, warranty, promise or other agreement
of Landlord or Landlord's agent(s), if any, not contained in this Lease or in
any Exhibit attached hereto.

                                   ARTICLE 15

                                OPTIONS TO EXTEND

15.1 So long as Juniper Networks, Inc. (or a Permitted Assignee) is the Tenant
hereunder, and subject to the condition set forth in clause (b) below, Tenant
shall have two options to extend the term of this Lease with respect to the
entirety of the Leased Premises, the first for a period of five (5) years from
the expiration of the last year of the Lease Term (the "First Extension
Period"), and the second (the "Second Extension Period") for a period of five
(5) years from the expiration of the First Extension Period, subject to the
following conditions:

      (a) Each option to extend shall be exercised, if at all, by notice of
exercise given to Landlord by Tenant not more than twelve (12) months nor less
than nine (9) months prior to the expiration of the last year of the Lease Term
or the expiration of the First Extension Period, as applicable;

      (b) Anything herein to the contrary notwithstanding, if Tenant is in
default under any of the material terms, covenants or conditions of this Lease,
either at the time Tenant exercises either extension option or on the
commencement date of the First Extension Period or the Second Extension Period,
as applicable, Landlord shall have, in addition to all of Landlord's other
rights and remedies provided in this Lease, the right to terminate such
option(s) to extend upon notice to Tenant.

15.2 In the event the applicable option is exercised in a timely fashion, the
Lease shall be extended for the term of the applicable extension period upon all
of the terms and conditions of this Lease, provided that the Base Monthly

                                       25
<PAGE>

Rent for each extension period shall be the "Fair Market Rent" for the Leased
Premises, determined as set forth below, with annual increases as determined as
part of the process set forth below.

15.3 Within 30 days after receipt of Tenant's notice of exercise, Landlord shall
notify Tenant in writing of Landlord's estimate of the Base Monthly Rent for the
first year of the applicable extension period, and Landlord's estimate of annual
increases. For purposes hereof, "Fair Market Rent" shall mean collectively, (1)
Base Monthly Rent for the first year of the applicable extension period and (2)
the annual increases determined at the time Base Monthly Rent for the first year
is determined. Within 30 days after receipt of such notice from Landlord, Tenant
shall have the right either to (i) accept Landlord's estimate of Fair Market
Rent or (ii) elect to arbitrate Landlord's estimate of Fair Market Rent, such
arbitration to be conducted pursuant to the provisions hereof. Failure on the
part of Tenant to require arbitration of Fair Market Rent within such 30-day
period shall constitute acceptance of the Fair Market Rent for the applicable
extension period as calculated by Landlord. If Tenant elects arbitration, the
arbitration shall be concluded within 90 days after the date of Tenant's
election, subject to extension for an additional 30-day period if a third
arbitrator is required and does not act in a timely manner. To the extent that
arbitration has not been completed prior to the expiration of any preceding
period for which Base Monthly Rent has been determined, Tenant shall pay Base
Monthly Rent at the rate calculated by Landlord, with the potential for an
adjustment to be made once Fair Market Rent is ultimately determined by
arbitration.

15.4 In the event of arbitration, the judgment or the award rendered in any such
arbitration may be entered in any court having jurisdiction and shall be final
and binding between the parties. The arbitration shall be conducted and
determined in the City and County of San Francisco in accordance with the then
prevailing rules of the American Arbitration Association or its successor for
arbitration of commercial disputes except to the extent that the procedures
mandated by such rules shall be modified as follows:

      (a) Tenant shall make demand for arbitration in writing within 30 days
after service of Landlord's determination of Fair Market Rent given under
Paragraph 15.3 above, specifying therein the name and address of the person to
act as the arbitrator on its behalf. The arbitrator shall be qualified as a real
estate appraiser familiar with the Fair Market Rent of similar industrial,
research and development, or office space in the Silicon Valley area who would
qualify as an expert witness over objection to give opinion testimony addressed
to the issue in a court of competent jurisdiction. Failure on the part of Tenant
to make a proper demand in a timely manner for such arbitration shall constitute
a waiver of the right thereto. Within 15 days after the service of the demand
for arbitration, Landlord shall give notice to Tenant, specifying the name and
address of the person designated by Landlord to act as arbitrator on its behalf
who shall be similarly qualified. If Landlord fails to notify Tenant of the
appointment of its arbitrator, within or by the time above specified, then the
arbitrator appointed by Tenant shall be the arbitrator to determine the issue.

      (b) In the event that two arbitrators are chosen pursuant to Paragraph
15.4(a) above, the arbitrators so chosen shall, within 15 days after the second
arbitrator is appointed determine the Fair Market Rent. If the two arbitrators
shall be unable to agree upon a determination of Fair Market Rent within such
15-day period, they, themselves, shall appoint a third arbitrator, who shall be
a competent and impartial person with qualifications similar to those required
of the first two arbitrators pursuant to Paragraph 15.4(a). In the event they
are unable to agree upon such appointment within seven days after expiration of
such 15-day period, the third arbitrator shall be selected by the parties
themselves, if they can agree thereon, within a further period of 15 days. If
the parties do not so agree, then either party, on behalf of both, may request
appointment of such a qualified person by the then Chief Judge of the United
States District Court having jurisdiction over the County of Santa Clara, acting
in his private and not in his official capacity, and the other party shall not
raise any question as to such Judge's full power and jurisdiction to entertain
the application for and make the appointment. The three arbitrators shall decide
the dispute if it has not previously been resolved by following the procedure
set forth below.

      (c) Where an issue cannot be resolved by agreement between the two
arbitrators selected by Landlord and Tenant or settlement between the parties
during the course of arbitration, the issue shall be resolved by the three
arbitrators within 15 days of the appointment of the third arbitrator in
accordance with the following procedure. The arbitrator selected by each of the
parties shall state in writing his determination of the Fair Market Rent
supported by the reasons therefor with counterpart copies to each party. The
arbitrators shall arrange for a simultaneous exchange of such proposed
resolutions. The role of the third arbitrator shall be to select which of the
two proposed resolutions most closely approximates his determination of Fair
Market Rent. The third arbitrator shall have no right to propose a middle ground
or any modification of either of the two proposed resolutions. The resolution he
chooses as most closely approximating his determination shall constitute the
decision of the arbitrators and be final and binding upon the parties.

      (d) In the event of a failure, refusal or inability of any arbitrator to
act, his successor shall be appointed by him, but in the case of the third
arbitrator, his successor shall be appointed in the same manner as provided for
appointment of the third arbitrator. The arbitrators shall decide the issue
within 15 days after the appointment of the third arbitrator. Any decision in
which the arbitrator appointed by Landlord and the arbitrator appointed by
Tenant concur shall be binding and conclusive upon the parties. Each party shall
pay the fee and expenses of its respective arbitrator and both shall share the
fee and expenses of the third arbitrator, if any, and the attorneys' fees and
expenses of counsel for the respective parties and of witnesses shall be paid by
the respective party engaging such counsel or calling such witnesses.

      (e) The arbitrators shall have the right to consult experts and competent
authorities to obtain factual information or evidence pertaining to a
determination of Fair Market Rent, but any such consultation shall be made in
the presence of both parties with full right on their part to cross-examine. The
arbitrators shall render their decision and award in writing with counterpart
copies to each party. The arbitrators shall have no power to modify the
provisions of this Lease.

                                       26
<PAGE>

                                   ARTICLE 16

                                TELEPHONE SERVICE

      Notwithstanding any other provision of this Lease to the contrary:

      (a) So long as the entirety of the Building is leased to Tenant:

            (i) Landlord shall have no responsibility for providing to Tenant
any telephone equipment, including wiring, within the Leased Premises or for
providing telephone service or connections from the utility to the Leased
Premises; and

            (ii) Landlord makes no warranty as to the quality, continuity or
availability of the telecommunications services in the Building, and Tenant
hereby waives any claim against Landlord for any actual or consequential damages
(including damages for loss of business) in the event Tenant's
telecommunications services in any way are interrupted, damaged or rendered less
effective, except to the extent caused by the grossly negligent or willful act
or omission by Landlord, its agents or employees. Tenant accepts the telephone
equipment (including, without limitation, the INC, as defined below) in its
"AS-IS" condition, and Tenant shall be solely responsible for contracting with a
reliable third party vendor to assume responsibility for the maintenance and
repair thereof (which contract shall contain provisions requiring such vendor to
inspect the INC periodically (the frequency of such inspections to be determined
by such vendor based on its experience and professional judgment), and requiring
such vendor to meet local and federal requirements for telecommunications
material and workmanship). Landlord shall not be liable to Tenant and Tenant
waives all claims against Landlord whatsoever, whether for personal injury,
property damage, loss of use of the Leased Premises, or otherwise, due to the
interruption or failure of telephone services to the Leased Premises. Tenant
hereby holds Landlord harmless and agrees to indemnify, protect and defend
Landlord from and against any liability for any damage, loss or expense due to
any failure or interruption of telephone service to the Leased Premises for any
reason. Tenant agrees to obtain loss of rental insurance adequate to cover any
damage, loss or expense occasioned by the interruption of telephone service.

      (b) At such time as the entirety of the Building is no longer leased to
Tenant, Landlord shall in its sole discretion have the right, by written notice
to Tenant, to elect to assume limited responsibility for INC, as provided below,
and upon such assumption of responsibility by Landlord, this subparagraph (b)
shall apply prospectively.

            (i) Landlord shall provide Tenant access to such quantity of pairs
in the Building intra-building network cable ("INC") as is determined to be
available by Landlord in its reasonable discretion. Tenant's access to the INC
shall be solely by arrangements made by Tenant, as Tenant may elect, directly
with Pacific Bell or Landlord (or such vendor as Landlord may designate), and
Tenant shall pay all reasonable charges as may be imposed in connection
therewith. Pacific Bell's charges shall be deemed to be reasonable. Subject to
the foregoing, Landlord shall have no responsibility for providing to Tenant any
telephone equipment, including wiring, within the Leased Premises or for
providing telephone service or connections from the utility to the Leased
Premises, except as required by law.

            (ii) Tenant shall not alter, modify, add to or disturb any telephone
wiring in the Leased Premises or elsewhere in the Building without the
Landlord's prior written consent, which consent shall not be unreasonably
withheld. Tenant shall be liable to Landlord for any damage to the telephone
wiring in the Building due to the act, negligent or otherwise, of Tenant or any
employee, contractor or other agent of Tenant. Tenant shall have no access to
the telephone closets within the Building, except in the manner and under
procedures established by Landlord. Tenant shall promptly notify Landlord of any
actual or suspected failure of telephone service to the Leased Premises.

            (iii) All costs incurred by Landlord for the installation,
maintenance, repair and replacement of telephone wiring in the Building shall be
a Property Maintenance Cost.

            (iv) Landlord makes no warranty as to the quality, continuity or
availability of the telecommunications services in the Building, and Tenant
hereby waives any claim against Landlord for any actual or consequential damages
(including damages for loss of business) in the event Tenant's
telecommunications services in any way are interrupted, damaged or rendered less
effective, except to the extent caused by the grossly negligent or willful act
or omission by Landlord, its agents or employees. Tenant acknowledges that
Landlord meets its duty of care to Tenant with respect to the Building INC by
contracting with a reliable third party vendor to assume responsibility for the
maintenance and repair thereof (which contract shall contain provisions
requiring such vendor to inspect the INC periodically (the frequency of such
inspections to be determined by such vendor based on its experience and
professional judgment), and requiring such vendor to meet local and federal
requirements for telecommunications material and workmanship). Subject to the
foregoing, Landlord shall not be liable to Tenant and Tenant waives all claims
against Landlord whatsoever, whether for personal injury, property damage, loss
of use of the Leased Premises, or otherwise, due to the interruption or failure
of telephone services to the Leased Premises. Tenant hereby holds Landlord
harmless and agrees to indemnify, protect and defend Landlord from and against
any liability for any damage, loss or expense due to any failure or interruption
of telephone service to the Leased Premises for any reason. Tenant agrees to
obtain loss of rental insurance adequate to cover any damage, loss or expense
occasioned by the interruption of telephone service.

                                       27
<PAGE>

      IN WITNESS WHEREOF, Landlord and Tenant have executed this Lease as of the
respective dates below set forth with the intent to be legally bound thereby as
of the Effective Date of this Lease first above set forth.

                              LANDLORD:

                              MATHILDA ASSOCIATES II LLC, a California limited
                              liability company

                              By:  Menlo Equities LLC, a California
                                   limited liability company, Manager

Dated: September 7, 2000      By: Diamant Investments LLC, a Delaware
                                       limited liability company, Member

                                       By: /s/ Richard J. Holmstrom
                                           -----------------------------
                                           Richard J. Holmstrom, Manager

                              TENANT:

                              JUNIPER NETWORKS, INC., a Delaware corporation

Dated: August 17, 2000        By: /s/ Lisa C. Berry
                                  -------------------------------------------
                              Title: Vice President, General Counsel
                                     and Secretary


                                       28
<PAGE>

                                    EXHIBIT A

                                    SITE PLAN

                                (To be attached)

                                       1
<PAGE>

                                    EXHIBIT B

                                   WORK LETTER

      THIS WORK LETTER, dated August 15, 2000, is entered into by and between
MATHILDA ASSOCIATES II LLC ("Landlord"), and JUNIPER NETWORKS, INC., a Delaware
corporation ("Tenant"). On or about the date hereof, Landlord and Tenant entered
into that certain Lease (the "Lease") for certain premises (the "Leased
Premises") commonly known as 1220 Mathilda Avenue, Sunnyvale, California. This
Work Letter sets forth the agreement of Landlord and Tenant with respect to the
improvements to be constructed in the Leased Premises. All defined terms used
herein shall have the meaning set forth in the Lease, unless otherwise defined
in this Work Letter.

1. CONSTRUCTION OF TENANT IMPROVEMENTS. Landlord shall, through a general
contractor to be selected pursuant to Paragraph 4 of this Work Letter, furnish
and install within the Building, substantially in accordance with the Work
Letter, certain items of general construction as described herein (the "Tenant
Improvements"). The quantities, character and manner of installation of all of
the Tenant Improvements shall be subject to the limitations imposed by any
applicable governmental regulations relating to conservation of energy and by
applicable building codes and regulations. In addition, Tenant agrees that the
Tenant Improvements shall not require Landlord to perform work which would (i)
require changes to structural components of the Building or the exterior design
of the Building; (ii) be incompatible with the Base Building Plans (defined
below) or the use permit to be issued by the City of Sunnyvale (the "Use
Permit"); or (iii) delay the completion of the Tenant Improvements beyond the
Intended Delivery Date.

2. BASE BUILDING PLANS. Robinson Mills + Williams (the "Architect") will prepare
building plans and specifications on behalf of Landlord ("Base Building Plans").
Landlord hereby agrees to construct the Base Building in accordance with the
Base Building Plans and the cost thereof shall not be deducted from the Tenant
Improvement Allowance. Tenant acknowledges that the Base Building may be based
on a floor area ratio of 50% (and may be up to 55%) and that the number of
square feet within the Leased Premises shall be determined in accordance with
Paragraph 2.5 of the Lease.

3. PREPARATION AND APPROVAL OF SPACE PLAN. Tenant shall make its representatives
available to meet with the Architect in order to begin the programming
process. The Tenant shall work with the Architect to complete the
programming and preliminary design for Architect's preparation of space plans
(the "Space Plans"). Such Space Plans shall be approved by Tenant and submitted
for Landlord's review no later than September 30, 2001. Within five (5) business
days after Landlord receives the Space Plans, Landlord shall either approve or
disapprove the Space Plans. In such event, the Architect shall make the minimum
changes necessary in order to correct any design problems identified by the
Landlord and shall submit to Landlord and Tenant revised Space Plans, which
Landlord and Tenant shall approve or disapprove within two (2) business days
after receipt of the revised Space Plans. This procedure shall be repeated until
the Space Plans are finally approved by Landlord and Tenant.

4. SELECTION OF CONTRACTOR. Landlord's contractor shall be the contractor
selected pursuant to a procedure whereby the Space Plans are submitted to three
(3) contractors, selected by Landlord and approved by Tenant, who are requested
to each submit a proposal containing the contractor's fee and general conditions
for construction of the improvements designated on the Space Plans. Landlord and
Tenant shall jointly open and review the fees and general conditions and the
qualifications of each contractor, and shall select the contractor reasonably
acceptable to both Landlord and Tenant ("Contractor"). Landlord and Contractor
shall enter into a construction contract (the "Construction Contract")
consistent with the terms of the bid to construct the Tenant Improvements. The
Construction Contract shall require that all subtrades be competitively bid with
at least three (3) subcontractors. Tenant shall have the right to propose
subcontractors to be used by the Contractor. Subcontracts shall be awarded to
the lowest qualified bidder, unless otherwise agreed by Landlord and Tenant.

5. DESIGN DEVELOPMENT. As soon as possible after Landlord's approval of the
Space Plans, Tenant shall commence working with the Architect to determine
Tenant's design specifications and requirements, such that the Architect can
incorporate such specifications and requirements into plans (the "Design
Development Plans") no later than November 15, 2001. The Design Development
Plans shall include specifications for mechanical, electrical, plumbing, HVAC
and cabling, as developed by Architect and its subconsultants on a
"design-build" basis. Within five (5) business days Landlord receives the Design
Development Plans, Landlord shall either approve or disapprove the Design
Development Plans. In such event, the Architect shall make the minimum changes
necessary in order to correct any design problems identified by the Landlord and
shall submit to Landlord and Tenant revised Design Development Plans, which
Landlord and Tenant shall approve or disapprove within two (2) business days
after receipt of the revised Design Development Plans. This procedure shall be
repeated until the Design Development Plans are finally approved by Landlord and
Tenant.

6. APPROVAL OF WORKING DRAWINGS.

      (a) After approval of the Design Development Plans and selection of the
Contractor, the Architect shall prepare complete and coordinated architectural
plans and specifications required for the construction of the Tenant
Improvements in conformance with such Space Plans (the "Working Drawings"), and
to prepare drawings and specifications for Changes (as defined below), if any,
requested or required pursuant to Paragraph 8 below.

      (b) Landlord shall submit the completed and coordinated Working Drawings
to Tenant for Tenant's approval. Tenant will provide written approval of the
Working Drawings within five (5) business days after such submission. If Tenant
disapproves any part of the submission, the disapproval shall include written
instructions

                                       1
<PAGE>

adequate for the Architect to revise the Working Drawings. Such revisions shall
be subject to Landlord's approval, which shall not be unreasonably withheld.
Tenant will finally approve the revised Working Drawings within five (5)
business days after submission thereof to Tenant. If Tenant's instructions
necessitate (i) revisions to the Working Drawings (as originally submitted)
which do not conform with the Design Development Plans, or (ii) a change of
scope relative to the Space Plans, the costs incurred by Landlord as a result of
such instructions (including, without limitation, the cost of revising the
Working Drawings) shall be promptly borne and paid by Tenant upon demand by
Landlord.

      (c) If Tenant fails to approve the Working Drawings within the applicable
periods set forth in subparagraph 5(b) above, then (A) Landlord shall not be
obligated to commence construction of the Tenant Improvements, (B) Tenant shall
be responsible for any resulting delay, and the cost of such delay, in
Landlord's completion of the Tenant Improvements and delivery of the Leased
Premises, and (C) any such delay shall be deemed a Tenant Delay (as defined
below).

7. COST OF TENANT IMPROVEMENTS. Unless specified otherwise herein, Landlord
shall bear and pay the cost of the Tenant Improvements (which cost shall
include, without limitation, the costs of construction, the cost of permits and
permit expediting, and all architectural and engineering services obtained by
Landlord in connection with the Tenant Improvements, the Contractor's fees,
Landlord's fee for construction administration in an amount equal to the amount
charged by any construction manager retained by Landlord (the "Construction
Manager") up to a maximum of $50 per rentable square foot (the "Tenant
Improvement Allowance"). The Tenant Improvement Allowance shall be utilized only
for building improvements to the Building (and Tenant's architect fees), and not
for signage, furniture costs, any third party consulting or contracting fees,
any telecom/cabling costs, or any other purpose. Tenant shall bear and pay the
cost of the Tenant Improvements (including but not limited to all of the
foregoing fees and costs) in excess of the Tenant Improvement Allowance, if any.
The cost of the Tenant Improvements shall exclude the cost of furniture,
fixtures and inventory and other items of Tenant's Work (as defined below).
Notwithstanding the foregoing, the Tenant Improvement Allowance shall not be
used for (and Tenant shall have no responsibility for) the following costs
except to the extent any of the foregoing are caused by Tenant, are due to
Tenant Delays or result from the failure of Tenant to comply with the terms of
the Lease or this Work Letter: (1) Property Maintenance Costs prior to the
Delivery Date; (2) charges for overtime, except to the extent approved by
Tenant; (3) costs to correct construction defects; (4) costs incurred to enforce
contracts or cure contractor or subcontractor defaults (including legal fees);
or (5) principal or interest on construction loan obtained by Landlord for
construction of the Tenant Improvements.

8. CHANGES.

      (a) Any request by Tenant for a change in the Tenant Improvements after
approval of the Final Plans (a "Change") shall be accompanied by all information
necessary to clearly identify and explain the proposed Change. As soon as
practicable after receipt of such an Estimate Request form, Landlord shall
notify Tenant of the estimated cost of such Change as well as the estimated
increase in construction time caused by the Change, if any. Tenant shall approve
in writing such estimates within two (2) business days after receipt of
Landlord's notice. Upon receipt of such written request, Landlord shall be
authorized to cause the Contractor to proceed with the implementation of the
requested Change.

      (b) The increased cost and time, as determined by Landlord, of all
Changes, including the cost of architectural and engineering services required
to revise the Working Drawings to reflect such Changes, the Contractor's
overhead and fee, and Landlord's fee for construction administration services,
shall be treated as costs of the Tenant Improvements, and shall be as determined
by Landlord upon completion of the Tenant Improvements, subject only to
Landlord's furnishing to Tenant appropriate back-up information from the
Contractor concerning the increased costs and increased construction time.

9. TENANT'S WORK. Landlord and Tenant acknowledge and agree that certain work
required for Tenant's occupancy of the Leased Premises, including but not
limited to the procurement and installation of furniture, fixtures, equipment,
artwork and interior signage are beyond the scope of the Tenant Improvements and
shall be performed by Tenant or its contractors at Tenant's sole cost and
expense. All such work ("Tenant's Work") shall be subject to Landlord's prior
written approval. Tenant shall adopt a construction schedule for Tenant's Work
in conformance with the Contractor's schedule, and shall perform Tenant's Work
in such a way as not to hinder or delay the operations of Landlord or the
Contractor in the Building. Any costs incurred by Landlord as a result of any
interference with Landlord's operations by Tenant or its contractors shall be
promptly paid by Tenant to Landlord upon demand. Landlord shall make all
reasonable efforts to notify Tenant of any such interference of which Landlord
has actual knowledge, but failure to provide such notice shall in no way limit
Landlord's right to demand payment for such costs. Tenant's contractors shall be
subject to Landlord's prior written approval, and to the administrative
supervision of the Contractor. Tenant's Work shall comply with all of the
following requirements:

      (a) Tenant's Work shall not proceed until Landlord has approved in
writing: (i) Tenant's contractors, (ii) proof of the amount and coverage of
public liability and property damage insurance carried by Tenant's contractors
in the form of an endorsed insurance certificate naming Landlord, the
Contractor, and the agents of Landlord and the Contractor as additional
insureds, in an amount not less than two million dollars, and (iii) complete and
detailed plans and specifications for Tenant's Work.

      (b) Tenant's Work shall be performed in conformity with a valid permit
when required, a copy of which shall be furnished to Landlord before such work
is commenced. In any event, all Tenant's Work shall comply with all applicable
laws, codes and ordinances of any governmental entity having jurisdiction over
the Building.

                                       2
<PAGE>

Landlord shall have no responsibility for Tenant's failure to comply with such
applicable laws. Any and all delay in obtaining a certificate of occupancy due
to Tenant's vendors is the responsibility of Tenant and shall be a Tenant Delay.

      (c) In connection with Tenant's Work (e.g., delivering or installing
furniture or equipment to the second floor of the Leased Premises), Tenant or
its contractors shall arrange for any necessary hoisting or elevator service
with Landlord and shall pay such reasonable costs for such services as may be
charged by Landlord.

      (d) Tenant shall promptly pay Landlord upon demand for any extra expense
incurred by Landlord by reason of faulty work done by Tenant or its contractors,
by reason of damage to existing work caused by Tenant or its contractors, or by
reason of inadequate cleanup by Tenant or its contractors.

10. COMPLETION; TENANT DELAY.

      (a) As used herein, the term "Substantial Completion of the Tenant
Improvements" shall be deemed to mean the date when all of the following shall
have occurred: (i) Landlord shall have delivered to Tenant a certificate of
occupancy issued by the City of Sunnyvale for the Leased Premises, or Tenant may
legally occupy the Leased Premises for the operation of its business without
violating any law or regulation or voiding or adversely affecting its insurance
coverage, whether pursuant to a temporary certificate of occupancy or otherwise;
and (ii) Landlord shall have substantially completed construction of the Base
Building substantially in accordance with the Base Building Plans and all Tenant
Improvements substantially in accordance with the Final Plans, subject only to
the completion of reasonable punch list items, which, in the absence of manifest
error, shall be established by a certificate executed by Landlord's architect
certifying that such state of completion has been achieved. Without limiting the
generality of the foregoing, "Substantial Completion of the Tenant Improvements"
shall not be deemed to have been achieved unless and until (i) the building
systems, including roof, plumbing, HVAC, sprinkler, electrical (including panels
and outlets), doors (both personnel and shipping), lighting, ceiling tiles, and
window coverings are in good working order, (ii) the interior and exterior of
the Building are in compliance with all applicable Laws, (iii) all debris and
clutter has been removed from the Leased Premises and final cleanup completed,
(iv) exterior windows are washed inside and out, and (v) parking lot and
landscaping are in good condition and free of debris, clutter and all
construction equipment. After substantial completion of the Tenant Improvements
and delivery of the Leased Premises to Tenant, Landlord and Tenant shall execute
a Lease Commencement Date Certificate in the form attached as Exhibit "C" to the
Lease.

      (b) If Landlord shall be delayed in substantially completing the Tenant
Improvements as a result of:

            (i) Tenant's failure to furnish the information, instructions and
plans required in paragraph 3 or approve the Working Drawings, within the
applicable time periods specified in paragraph 5; or

            (ii) Any changes in the scope of the Tenant Improvements from that
set forth in the Space Plans, or any Changes to the Final Plans requested by
Tenant after approval thereof pursuant to paragraph 7; or

            (iii) Any interruption or interference in Landlord's construction of
the Tenant Improvements caused by Tenant, its contractors or its vendors; or

            (iv) Tenant's failure to timely pay any amounts which Tenant is
obligated to pay under this Work Letter; or

            (v) Any other act, neglect, failure or omission of Tenant, its
agents, employees or contractors (items (i) through (v) above being collectively
referred to as "Tenant Delays");

then the date upon which the payment of rental under the Lease, shall commence
shall be advanced by the cumulative duration of such Tenant Delays.

11. CONSTRUCTION WARRANTY. Landlord shall construct the Tenant Improvements
substantially in accordance with this Work Letter and the Final Plans, all Laws
and Private Restrictions, and in a good and workmanlike manner, and all
materials and equipment furnished will substantially conform to said plans and
shall be new and otherwise of good quality. Landlord's Contractor and
subcontractors shall be responsible for the correction of defects in design,
workmanship, materials and equipment supplied, and the cost of correction shall
not be charged against the Tenant Improvement Allowance or be a Property
Maintenance Expense.

12. OWNERSHIP OF TENANT IMPROVEMENTS. All of the Tenant Improvements which are
constructed with the Tenant Improvement Allowance shall become the property of
Landlord upon installation and shall not be removed or altered by Tenant, except
to the extent permitted by the Lease. Any part of the Tenant Improvements which
are constructed by Landlord with funds of Tenant shall become the property of
Tenant upon installation and Tenant shall have the right to depreciate and claim
and collect investment tax credits in such improvements; provided, however, that
(i) Tenant shall not remove or alter such improvements except in accordance with
the terms of the Lease; (ii) such improvements shall be surrendered to Landlord,
and title to such improvements shall vest in Landlord, at the expiration or
earlier termination of the Lease Term; and (iii) in no event shall Landlord have
any obligation to pay Tenant for the cost or value of such improvements. As soon
as reasonably practicable, Landlord and Tenant shall agree in writing which of
such improvements are to be constructed using the Tenant Improvement Allowance
(and therefore are Landlord's property) and which of them are to be installed
with Tenant's funds (and therefore are Tenant's property) during the Lease Term.

                                       3
<PAGE>

13. DESIGNATION OF AGENT. Tenant hereby designates and appoints Nova Partners
("Agent") as its agent to act on its behalf with respect to its duties and
obligations under this Work Letter. For the purposes of this appointment,
Agent's authority shall specifically include, but in no way be limited to, the
following: (i) the approval of the Design Development Plans, (ii) the submission
of any Changes, (iii) the delivery of any Estimate Requests, (iv) the approval
of any Landlord responses to Estimate Requests, (v) the approval of all costs
and time, including architectural and engineering services, required to revise
the Working Drawings to reflect any Changes, (v) the authorization of any
overtime, and (vi) the authority to execute and deliver to Landlord any written
authorizations requested by Landlord in connection with the construction of the
Tenant Improvements. Tenant expressly acknowledges that this Appointment is made
with the knowledge that Landlord and it affiliates will rely on the authority
granted to Agent herein. Accordingly, Landlord shall be deemed a third party
beneficiary of this Appointment. Tenant further acknowledges that the authority
hereby conferred will continue in full force and effect until Landlord shall
receive notice in writing, signed by the Tenant, of the revocation of the
authority herein granted. Such revocation shall be effective only as to actions
taken by the Agent subsequent to receipt by Landlord of such notice. Tenant
agrees to indemnify, defend and hold Landlord harmless from any and all claims,
liabilities, losses, damages, costs and expenses, including without limitation,
all reasonable attorneys' fees, asserted against or suffered by Landlord
resulting from Landlord's reliance on this appointment.

      IN WITNESS WHEREOF, Landlord and Tenant have executed this Work Letter as
of the respective dates set forth below.

                              LANDLORD:

                              MATHILDA ASSOCIATES II LLC, a California limited
                              liability company

                              By:  Menlo Equities LLC, a California
                                   limited liability company, Manager

Dated: September 7, 2000      By:  Diamant Investments LLC, a Delaware limited
                                   liability company, Member

                                   By:/s/ Richard J. Holmstrom
                                      -------------------------------------
                                      Richard J. Holmstrom, Manager

                              TENANT:

                              JUNIPER NETWORKS, INC., a Delaware corporation

Dated: August 17, 2000        By: /s/ Lisa C. Berry
                                  ------------------------------------------
                              Title: Vice President, General Counsel
                                     and Secretary

                                       4
<PAGE>

                                    EXHIBIT C

                       LEASE COMMENCEMENT DATE CERTIFICATE

This Lease Commencement Date Certificate is entered into by Landlord and Tenant
pursuant to the Work Letter attached as Exhibit B to the Lease.

<TABLE>
<S>   <C>   <C>               <C>
1.    (a)   Landlord:         Mathilda Associates II LLC, a California limited liability company
      (b)   Tenant:           Juniper Networks, Inc., a Delaware corporation
      (c)   Lease:            Lease dated August 15, 2000 between Landlord and Tenant.
      (d)   Leased Premises:  1220 Mathilda Avenue, Sunnyvale, California
</TABLE>

2.    CONFIRMATION OF LEASE COMMENCEMENT.

      Landlord and Tenant confirm that the Lease Commencement Date is
____________ and the Expiration Date is ______________ and that Article 1 of the
Lease is amended accordingly.

      Landlord and Tenant have executed this Lease Commencement Date Certificate
as of the dates set forth below.

                              LANDLORD:

                              MATHILDA ASSOCIATES II LLC, a California limited
                              liability company

                              By:   Menlo Equities LLC, a California
                                    limited liability company

Dated:_____________________         By:____________________________Member

                              TENANT:

                              JUNIPER NETWORKS, INC., a Delaware corporation

Dated:_____________________   By:___________________________________________
                              Title:________________________________________

Dated:_____________________   By:___________________________________________
                              Title:________________________________________

                                       1
<PAGE>

                                    EXHIBIT D

                          FORM OF ESTOPPEL CERTIFICATE

_________________,_____

______________________________
______________________________
______________________________
______________________________

Re  1220 Mathilda Avenue
    Sunnyvale, California

Ladies and Gentlemen:

Reference is made to that certain Lease, dated as of August 15, 2000, between
MATHILDA ASSOCIATES II LLC, a California limited liability company ("Landlord"),
and the undersigned (herein referred to as the "Lease"). A copy of the Lease
[and all amendment thereto] is[are] attached hereto as EXHIBIT A. At the request
of Landlord in connection with [ State reasons for request for estoppel
certificate ], the undersigned hereby certifies to Landlord and to [ State names
of other parties requiring certification ] and each of your respective
successors and assigns as follows:

      1. The undersigned is the tenant under the Lease.

      2. The Lease is in full force and effect and has not been amended,
modified, supplemented or superseded except as indicated in Exhibit A.

      3. There is no defense, offset, claim or counterclaim by or in favor of
the undersigned against Landlord under the Lease or against the obligations of
the undersigned under the Lease. The undersigned has no renewal, extension or
expansion option, no right of first offer or right of first refusal and no other
similar right to renew or extend the term of the Lease or expand the property
demised thereunder except as may be expressly set forth in the Lease.

      4. The undersigned is not aware of any default now existing of the
undersigned or of Landlord under the Lease, nor of any event which with notice
or the passage of time or both would constitute a default of the undersigned or
of Landlord under the Lease except____________________________________________.

      5. The undersigned has not received notice of a prior transfer,
assignment, hypothecation or pledge by Landlord of any of Landlord's interest in
the Lease.

      6. The monthly rent due under the Lease is $____________ and has been paid
through __________________, and all additional rent due and payable under the
Lease has been paid through _________________.

      7. The term of the Lease commenced on __________________, and expires on
___________________, unless sooner terminated pursuant to the provisions of the
Lease. Landlord has performed all work required by the Lease for the
undersigned's initial occupancy of the demised property.

      8. The undersigned has deposited the sum of $____________ with Landlord as
security for the performance of its obligations as tenant under the Lease, and
no portion of such deposit has been applied by Landlord to any obligation under
the Lease.

      9. Except as set forth in the Lease, there is no free rent period pending,
nor is Tenant entitled to any Landlord's contribution.

The above certifications are made to Landlord and Lender knowing that Landlord
and Lender will rely thereon in accepting an assignment of the Lease.

Very truly yours,

JUNIPER NETWORKS, INC., a Delaware corporation

By:___________________________________
Name:_________________________________
Title:________________________________

                                       1
<PAGE>

                                    EXHIBIT E

                             FORM OF LANDLORD WAIVER

      THIS LANDLORD WAIVER (this "Waiver") dated _______________, 2____, is
entered into by and between MATHILDA ASSOCIATES II LLC, a California limited
liability company ("Landlord") and ___________________ ("Secured Party").

                                    RECITALS

      WHEREAS, Landlord is the owner and landlord of the premises described as
1220 Mathilda Avenue, Sunnyvale, California (the "Property"); and

      WHEREAS, Landlord and Juniper Networks, Inc. ("Tenant") have entered into
that certain lease dated August 15, 2000 (as previously and/or hereafter
amended, the "Real Property Lease") pursuant to which Tenant has leased
approximately _____ square feet of space at the Property (the "Premises"); and

      WHEREAS, Tenant has entered into an equipment lease and/or financing
agreement pursuant to which Tenant has granted a security interest in the
personal property described on Schedule 1 attached hereto (the "Personal
Property") to Secured Party under that certain [Equipment Lease and/or Financing
Agreement] between Tenant and Secured Party dated __________ (the "Financing
Agreement"); and

      WHEREAS, Secured Party and Landlord desire to establish their respective
rights regarding the Personal Property and Secured Party's access to the
Premises;

                                    AGREEMENT

      NOW, THEREFORE, in consideration of the above Recitals and for other good
and valuable consideration, the receipt and adequacy of which are hereby
acknowledged, the parties hereto agree as follows:

      1. During the term of the Real Property Lease, and subject to Landlord's
interest in the Personal Property, if any, at the expiration or earlier
termination of the Real Property Lease, the Personal Property shall remain
personal property and severable from the Premises and shall not become part of
the Premises or construed as a fixture at the Premises to the extent that the
Tenant Improvement Allowance (as defined in the Real Property Lease) has not
been utilized to pay for the Personal Property or the financing thereof.

      2. So long as Tenant occupies the Premises and is not in default under the
Real Property Lease, Secured Party may enter the Premises at any time or from
time to time upon reasonable written notice to Landlord and in compliance with
the terms of the Financing Agreement for purposes of inspecting and/or removing
any and all of the Personal Property in the exercise of its rights and remedies
arising from the Financing Agreement. In the event of a default by Tenant under
the Real Property Lease, Secured Party shall obtain Landlord's prior written
consent prior to entering the Premises.

      3. Landlord shall notify Secured Party in the event the Personal Property
remains at the Premises after either (i) Tenant is evicted from the Premises or
(ii) Tenant abandons (as opposed to vacates) the Premises prior to the
expiration of the Real Property Lease. Secured Party shall have 15 days to
remove the Personal Property from the Premises after notification of such action
from Landlord. If Secured Party has not removed the Personal Property within
such 15 day period, Landlord shall have all rights regarding the Personal
Property accorded to it by law and/or pursuant to the Real Property Lease and
Secured Party shall have no further rights regarding such Personal Property.
After Tenant has abandoned or been evicted from the Premises, Secured Party
shall be liable for holdover rent for the total amount of time the Personal
Property remains at the Premises after such eviction or abandonment. For
purposes hereof, "holdover rent" shall mean 200% of the rent in effect under the
Real Property Lease for the period immediately prior to such vacation or
eviction.

      4. If Secured Party exercises its right to remove the Personal Property
from the Premises as provided herein, Secured Party shall repair any damage to
the Premises caused by such removal. Landlord shall have the right to require
Secured Party to post a bond acceptable to Landlord to cover the potential cost
of such repair prior to removing any such Personal Property.

      5. No auction or sale of the Personal Property shall be conducted by
Secured Party from the Premises without Landlord's prior written consent, which
consent Landlord may withhold in Landlord's sole and absolute discretion.

      6. This waiver shall be binding upon the heirs, administrators, executors,
successors and assigns of the Landlord, and shall inure to the benefit of the
successors and assigns of the Secured Party.

                                       1.
<PAGE>

      IN WITNESS WHEREOF, the parties hereto have executed, sealed and delivered
this Waiver this __________ day of ________________, 2____.

                              MATHILDA ASSOCIATES II LLC, a California limited
                              liability company

                              By:  Menlo Equities LLC, a California
                                   limited liability company

                                   By:_______________________________Member

                              SECURED PARTY:

                              By:___________________________________________
                              Title:________________________________________

                              By:___________________________________________
                              Title:________________________________________

                                       2.
<PAGE>

                                   SCHEDULE 1

                                PERSONAL PROPERTY

                                       3.
<PAGE>

                                TABLE OF CONTENTS

<TABLE>
<CAPTION>
                                                                                                                 PAGE
<S>                                                                                                              <C>
ARTICLE 1            REFERENCE................................................................................     1

      1.1       References....................................................................................     1

ARTICLE 2            LEASED PREMISES, TERM AND POSSESSION.....................................................     2

      2.1       Demise Of Leased Premises.....................................................................     2

      2.2       Right To Use Outside Areas....................................................................     3

      2.3       Lease Commencement Date And Lease Term........................................................     3

      2.4       Delivery Of Possession........................................................................     3

      2.5       Performance Of Tenant Improvements; Acceptance Of Possession..................................     3

      2.6       Surrender Of Possession.......................................................................     3

ARTICLE 3            RENT, LATE CHARGES AND SECURITY DEPOSITS.................................................     4

      3.1       Base Monthly Rent.............................................................................     4

      3.2       Additional Rent...............................................................................     4

      3.3       Year-End Adjustments..........................................................................     5

      3.4       Late Charge, And Interest On Rent In Default..................................................     5

      3.5       Payment Of Rent...............................................................................     5

      3.6       Prepaid Rent..................................................................................     5

      3.7       Security Deposit..............................................................................     5

ARTICLE 4            USE OF LEASED PREMISES AND OUTSIDE AREA..................................................     5

      4.1       Permitted Use.................................................................................     5

      4.2       General Limitations On Use....................................................................     6

      4.3       Noise And Emissions...........................................................................     6

      4.4       Trash Disposal................................................................................     6

      4.5       Parking.......................................................................................     6

      4.6       Signs.........................................................................................     6

      4.7       Compliance With Laws And Private Restrictions.................................................     7

      4.8       Compliance With Insurance Requirements........................................................     7

      4.9       Landlord's Right To Enter.....................................................................     7

      4.10      Use Of Outside Areas..........................................................................     7

      4.11      Environmental Protection......................................................................     7

      4.12      Rules And Regulations.........................................................................     8

      4.13      Reservations..................................................................................     9

ARTICLE 5            REPAIRS, MAINTENANCE, SERVICES AND UTILITIES.............................................     9

      5.1       Repair And Maintenance........................................................................     9

                (a)     Tenant's Obligations..................................................................     9

                (b)     Landlord's Obligation.................................................................     9

      5.2       Utilities.....................................................................................     9

      5.3       Security......................................................................................     9

      5.4       Energy And Resource Consumption...............................................................    10

      5.5       Limitation Of Landlord's Liability............................................................    10

ARTICLE 6            ALTERATIONS AND IMPROVEMENTS.............................................................    10

      6.1       By Tenant.....................................................................................    10

      6.2       Ownership Of Improvements.....................................................................    10

      6.3       Alterations Required By Law...................................................................    11

      6.4       Liens.........................................................................................    11

ARTICLE 7            ASSIGNMENT AND SUBLETTING BY TENANT........................................... ..........    11

      7.1       By Tenant.....................................................................................    11

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      7.2       Merger, Reorganization, or Sale of Assets..................................................       12

      7.3       Landlord's Election........................................................................       12

      7.4       Conditions To Landlord's Consent...........................................................       12

      7.5       Assignment Consideration And Excess Rentals Defined........................................       13

      7.6       Payments...................................................................................       13

      7.7       Good Faith.................................................................................       13

      7.8       Effect Of Landlord's Consent...............................................................       13

ARTICLE 8            LIMITATION ON LANDLORD'S LIABILITY AND INDEMNITY......................................       14

      8.1       Limitation On Landlord's Liability And Release.............................................       14

      8.2       Tenant's Indemnification Of Landlord.......................................................       14

ARTICLE 9            INSURANCE.............................................................................       14

      9.1       Tenant's Insurance.........................................................................       14

      9.2       Landlord's Insurance.......................................................................       15

      9.3       Mutual Waiver Of Subrogation...............................................................       15

ARTICLE 10           DAMAGE TO LEASED PREMISES.............................................................       16

      10.1      Landlord's Duty To Restore.................................................................       16

      10.2      Insurance Proceeds.........................................................................       16

      10.3      Landlord's Right To Terminate..............................................................       16

      10.4      Tenant's Right To Terminate................................................................       16

      10.5      Tenant's Waiver............................................................................       16

      10.6      Abatement Of Rent..........................................................................       17

ARTICLE 11           CONDEMNATION..........................................................................       17

      11.1      Tenant's Right To Terminate................................................................       17

      11.2      Landlord's Right To Terminate..............................................................       17

      11.3      Restoration................................................................................       17

      11.4      Temporary Taking...........................................................................       17

      11.5      Division Of Condemnation Award.............................................................       17

      11.6      Abatement Of Rent..........................................................................       17

      11.7      Taking Defined.............................................................................       17

ARTICLE 12           DEFAULT AND REMEDIES..................................................................       17

      12.1      Events Of Tenant's Default.................................................................       17

      12.2      Landlord's Remedies........................................................................       18

      12.3      Landlord's Default And Tenant's Remedies...................................................       19

      12.4      Limitation Of Tenant's Recourse............................................................       19

      12.5      Tenant's Waiver............................................................................       20

ARTICLE 13           GENERAL PROVISIONS....................................................................       20

      13.1      Taxes On Tenant's Property.................................................................       20

      13.2      Holding Over...............................................................................       20

      13.3      Subordination To Mortgages.................................................................       20

      13.4      Tenant's Attornment Upon Foreclosure.......................................................       20

      13.5      Mortgagee Protection.......................................................................       21

      13.6      Estoppel Certificate.......................................................................       21

      13.7      Tenant's Financial Information.............................................................       21

      13.8      Transfer By Landlord.......................................................................       21

      13.9      Force Majeure..............................................................................       21

      13.10     Notices....................................................................................       21
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      13.11     Attorneys' Fees......................................................................          22

      13.12     Definitions..........................................................................          22

                (a)  Real Property Taxes.............................................................          22

                (b)  Landlord's Insurance Costs......................................................          22

                (c)  Property Maintenance Costs......................................................          22

                (d)  Property Operating Expenses.....................................................          23

                (e)  Law.............................................................................          23

                (f)  Lender..........................................................................          23

                (g)  Private Restrictions............................................................          23

                (h)  Rent............................................................................          23

      13.13     General Waivers......................................................................          23

      13.14     Miscellaneous........................................................................          23

      13.15     Cooperation..........................................................................          24

ARTICLE 14           CORPORATE AUTHORITY BROKERS AND ENTIRE AGREEMENT................................          24

      14.1      Corporate Authority..................................................................          24

      14.2      Brokerage Commissions................................................................          24

      14.3      Entire Agreement.....................................................................          24

      14.4      Landlord's Representations...........................................................          24

ARTICLE 15           OPTIONS TO EXTEND...............................................................          24

ARTICLE 16           TELEPHONE SERVICE...............................................................          26
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                                       1.
<PAGE>

                            AMENDMENT NO. 1 TO LEASE

      This AMENDMENT NO. 1 TO LEASE (this "Amendment") is dated as of this 24th
day of January, 2002, by and between MATHILDA ASSOCIATES II LLC, a California
limited liability company ("Landlord"), and JUNIPER NETWORKS, INC., a Delaware
corporation ("Tenant").

                                    RECITALS

      A. Landlord and Tenant entered into that certain Lease Agreement dated
August 15, 2000 (the "Lease") for premises located in the City of Sunnyvale,
County of Santa Clara, State of California, commonly known as 1220 Mathilda
Avenue, comprised of 158,075 rentable square feet of floor area (the "Leased
Premises"). Capitalized terms used in this Amendment and not otherwise defined
shall have the meanings assigned to them in the Lease.

      B. Landlord and Tenant acknowledge and agree that Landlord will be able to
achieve Substantial Completion of the Tenant Improvements (as defined in the
Work Letter), and will be able to deliver possession of the Leased Premises to
Tenant, in the condition required by the Lease, by no later than May 1, 2002, in
which event the Lease Commencement Date would be June 1, 2002.

      C. Notwithstanding the foregoing, Tenant has requested that Landlord delay
Substantial Completion of the Tenant Improvements and delay delivery of
possession of the Leased Premises until September 3, 2002; and Landlord is
willing to do so provided that the Lease Commencement Date not be delayed and
otherwise on the terms and conditions set forth herein.

      D. Landlord and Tenant now desire to amend the Lease according to the
terms and conditions set forth herein.

                                    AGREEMENT

      NOW THEREFORE, for good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, Landlord and Tenant hereby agree
as follows:

      1. RECITALS. The foregoing Recitals are hereby incorporated into this
Amendment.

      2. INTENDED DELIVERY DATE. The term "Intended Delivery Date" which is
defined as "May 1, 2002" in Article 1 of the Lease, is hereby redefined to be
"September 3, 2002."

      3. RENTABLE SQUARE FOOTAGE OF LEASED PREMISES. Landlord and Tenant hereby
agree that the rentable square footage of Leased Premises is 158,075.

      4. LEASE COMMENCEMENT DATE. Section 2.3 of the Lease is hereby amended in
its entirety to read as follows:

          "2.3 LEASE COMMENCEMENT DATE AND LEASE TERM. The term of this Lease
      shall begin, and the Lease Commencement Date shall be deemed to have
      occurred, on June 1,

<PAGE>

      2002. The term of this Lease shall in all events end on the Lease
      Expiration Date (as set forth in Article 1). The Lease Term shall be that
      period of time commencing on the Lease Commencement Date and ending on the
      Lease Expiration Date (the "Lease Term")."

      5. PERFORMANCE OF TENANT IMPROVEMENTS; ACCEPTANCE OF POSSESSION. Section
2.5 of the Lease is hereby amended in its entirety to read as follows:

          "Landlord shall, pursuant to the work letter attached to and made a
          part of this Lease (the "Work Letter"), perform the work and make the
          installations in the Leased Premises substantially as set forth in the
          Work Letter (such work and installations hereinafter referred to as
          the "Tenant Improvements"). It is agreed that by occupying the Leased
          Premises, Tenant formally accepts same and acknowledges that the
          Leased Premises are in the condition called for hereunder, subject to
          reasonable punchlist items and latent defects specified by Tenant to
          Landlord in writing within ten (10) days of such occupancy."

      6. COST OF BUILDING CORE. Landlord, at Tenant's request, has performed
construction work on the Building core and has charged the cost thereof against
the Tenant Improvement Allowance. The work and cost detail has previously been
provided to and approved by Tenant.

      7. SURRENDER OF POSSESSION. The first sentence of Section 2.6 of the Lease
is hereby amended in its entirety to read as follows:

          "Immediately prior to the expiration or upon the sooner termination of
          this Lease, Tenant shall remove all of Tenant's signs from the
          exterior of the Building and shall remove all of Tenant's equipment,
          trade fixtures, furniture, supplies, wall decorations and other
          personal property from within the Leased Premises, the Building and
          the Outside Areas, and shall vacate and surrender the Leased Premises,
          the Building, the Outside Areas and the Property to Landlord in the
          same condition, broom clean, as existed at the Delivery Date, damage
          by casualty or condemnation (which events shall be governed by
          Articles 10 and 11) and reasonable wear and tear excepted."

      8. LANDLORD'S DUTY TO RESTORE. The second sentence of Section 10.1 of the
Lease is hereby amended in its entirety to read as follows:

          "If this Lease is not so terminated, then upon the issuance of all
          necessary governmental permits, Landlord shall commence and diligently
          prosecute to completion the restoration of the Leased Premises, the
          Building or the Outside Area, as the case may be, to the extent then
          allowed by law, to substantially the same condition in which it
          existed as of the Delivery Date."

      9. CONDITION PRECEDENT TO LEASE AMENDMENT. Landlord's obligations
hereunder are subject to the receipt by Landlord, no later than fifteen (15)
business days after the date hereof, of the Lender's Consent, as hereinafter
defined. Landlord hereby agrees to use diligent efforts to obtain the Lender's
Consent by such date; however, if Landlord does not receive the

<PAGE>

Lender's Consent by such date, this Amendment shall, at Landlord's option,
thereupon be deemed terminated and of no further force or effect, and neither
party shall have any further rights, obligations, or liabilities hereunder. As
used herein, the term "Lender's Consent" means a written consent to this
Amendment in form reasonably satisfactory to Landlord, executed by the holder of
the promissory note secured by that certain Deed of Trust (encumbering the fee
interest in the real property of which the Leased Premises are a part) recorded
on December 29, 2000 in the Official Records of Santa Clara County, California,
at Series No. 15512549.

      10. RATIFICATION. The Lease, as amended by this Amendment, is hereby
ratified by Landlord and Tenant and Landlord and Tenant hereby agree that the
Lease, as so amended, shall continue in full force and effect.

      11. MISCELLANEOUS.

          (a) VOLUNTARY AGREEMENT. The parties have read this Amendment and on
the advice of counsel they have freely and voluntarily entered into this
Amendment.

          (b) ATTORNEY'S FEES. If either party commences an action against the
other party arising out of or in connection with this Amendment, the prevailing
party shall be entitled to recover from the losing party reasonable attorney's
fees and costs of suit.

          (c) SUCCESSORS. This Amendment shall be binding on and inure to the
benefit of the parties and their successors.

          (d) COUNTERPARTS. This Amendment may be signed in two or more
counterparts. When at least one such counterpart has been signed by each party,
this Amendment shall be deemed to have been fully executed, each counterpart
shall be deemed to be an original, and all counterparts shall be deemed to be
one and the same agreement.

      IN WITNESS WHEREOF, Landlord and Tenant have executed this Amendment as of
the date first written above.

                                 TENANT:

                                 JUNIPER NETWORKS, INC., a Delaware corporation

                                 By: /s/ Lisa C. Berry
                                     -----------------------------------------
                                 Title:Vice President, General Counsel
                                       and Secretary

                       [SIGNATURES CONTINUED ON NEXT PAGE]

<PAGE>

                     [SIGNATURES CONTINUED FROM PRIOR PAGE]

                                 LANDLORD:

                                 MATHILDA ASSOCIATES II LLC, a California
                                 limited liability company

                                 By:  Menlo Equities LLC, a California
                                      limited liability company, Manager

                                      By: Diamant Investments LLC, a Delaware
                                          limited liability company, Member

                                          By: /s/ Richard J. Holmstrom
                                             -------------------------------
                                             Richard J. Holmstrom, Manager