<PAGE>

--------------------------------------------------------------------------------

                                                                   EXHIBIT 10.10

                                 LEASE AGREEMENT
                                 ---------------

                                     BETWEEN



                     WMP II REAL ESTATE LIMITED PARTNERSHIP,
                         A Delaware limited partnership



                                   AS LANDLORD


                                       AND


                    CABLETRON SYSTEMS SALES & SERVICE, INC.,
                             A Delaware corporation


                                    AS TENANT


                              Dated January 6, 1999



                                    Property:

                               Great America Plaza
                           5200 Great America Parkway
                          Santa Clara, California 95054

--------------------------------------------------------------------------------
<PAGE>

                            BASIC LEASE INFORMATION
                            -----------------------


Lease               Date: January 6, 1999

Tenant:             Cabletron Systems Sales & Service, Inc., a Delaware
                    corporation

Landlord:           WMP II Real Estate Partnership, a Delaware limited
                    partnership

Premises:           Approximately 129,200 square feet located in the office
                    building commonly known as Great America Plaza (the
                    "Building"), and whose street address is 5200 Great America
                     --------
                    Parkway, Santa Clara, California, 95054. The Premises are
                    outlined on the plan attached to the Lease as Exhibit A. The
                    land on which the Building is located (the "Land") is
                                                                ----
                    described on Exhibit B. The Land and the Building, together
                    with all driveways, facilities, and similar improvements,
                    including the office buildings known as 2903 Bunker Hill
                    Lane and 2933 Bunker Hill Lane, Santa Clara, California,
                    95054, are collectively referred to herein as the "Project".
                                                                       -------

Term:               Approximately eighty-four (84) months, commencing on March
                    1, 1999 (the "Commencement Date") and ending at 5:00 p.m. on
                                  -----------------
                    February 28, 2006 (the "Term", which definition shall
                                            ----
                    include all renewals of the initial Term), subject to
                    adjustment and earlier termination as provided in the Lease.

Option:             Two (2) options for sixty (60) months each

Basic               Rent: Basic Rent shall be the following amounts for the
                    following periods of time:


                    Lease Month               Monthly Basic Rent
                    -----------------------   ------------------

                    3/01/99-2/29/00             $197,676.00
                    3/01/00-2/28/01             $213,180.00
                    3/01/01-2/28/02             $226,100.00
                    3/01/02-2/28/03             $235,144.00
                    3/01/03-2/29/04             $244,549.76
                    3/01/04-2/28/05             $254,331.75
                    3/01/05-2/28/06             $264,505.02

                                      -i-
<PAGE>

                    Subject to Section 27, Monthly Basic Rent shall be abated
                    for the first three months of the Term. As used herein, the
                    term "Lease Month" shall mean each calendar month during the
                          -----------
                    Term (and if the Commencement Date does not occur on the
                    first day of a calendar month, the period from the
                    Commencement Date to the first day of the next calendar
                    month shall be included in the first Lease Month for
                    purposes of determining the duration of the Term and the
                    monthly Basic Rent rate applicable for such partial month).

Security Deposit:  None

Rent:               Basic Rent, Tenant's Proportionate Share of Taxes,
                    Additional Rent, and all other sums that Tenant may owe to
                    Landlord or otherwise be required to pay under the Lease.

Permitted           Use: General office, sales and research and development use.



Tenant's
Proportionate
Share:              For the Project: 56.74%, which is the percentage obtained by
                    dividing the 129,200 rentable square feet in the Premises by
                    the 227,699 rentable square feet in the Project; For the
                    Building: 100%, which is the percentage obtained by dividing
                    the 129,200 rentable square feet in the Premises by the
                    129,200 rentable square feet in the Building. Landlord and
                    Tenant stipulate that the number of rentable square feet in
                    the Premises, the Building and the Project set forth above
                    shall be binding upon them. In the event the Premises, the
                    Building, or the Project is remeasured or altered by
                    Landlord and the rentable square footages set forth above
                    are changed as a result, Tenant's Proportionate Share for
                    the Project and for the Building and all other items under
                    this Lease calculated on a per square foot basis, including
                    without limitation Basic Rent, shall be recalculated
                    accordingly.

Initial Liability
Insurance Amount:   $3,000,000.00

Maximum Tenant
Improvement
Allowance:          $10.00 per rentable square foot

Guarantor:          Cabletron Systems, Inc.

                                      -ii-
<PAGE>

Tenant's Address:




Following Commencement Date:                 With A Copy To:
----------------------------                 -----------------------------------
Cabletron Systems Sales & Service, Inc.      Cabletron Systems Sales & Service,
35 Industrial Way, Building 28               5200 Great America Parkway
Rochester, New Hampshire 03867               Santa Clara, California 95054
Attn:  Legal Department                      Attn:_____________________________
Facsimile: (603) 337-3295                    Facsimile:________________________

Landlord's Address:

For All Notices:                             With A Copy To:
----------------                             ---------------
WMP II Real Estate Limited Partnership       WMP II Real Estate Limited
c/o Archon Group                             Partnership, Inc. c/o Insignia
Two California Plaza                         Commercial Group, Inc. 160 West
350 South Grand Avenue, 46th Floor           Santa Clara Street, Suite 1350
Los Angeles, California 90071                San Jose, California 95113
Attn:  Nancy M. Haag                         Attn:  Mark Schmidt
Facsimile:  (213) 633-5870                   Facsimile:  (408) 288-2909


     For Rent Payments:
     -----------------
     WMP II Real Estate Limited Partnership
     C/o Insignia Commercial Group, Inc.
     160 West Santa Clara Street, Suite 1350
     San Jose, California 95113
     Attn:  Mark Schmidt


THE FOREGOING BASIC LEASE INFORMATION IS INCORPORATED INTO AND MADE A PART OF
THE LEASE IDENTIFIED ABOVE.  IF ANY CONFLICT EXISTS BETWEEN ANY BASIC LEASE
INFORMATION AND THE LEASE, THEN THE LEASE SHALL CONTROL.


LANDLORD:                     WMP II REAL ESTATE LIMITED
                              PARTNERSHIP, a Delaware limited
                              partnership

                              By:  WMP II GEN-PAR, INC., a Delaware Corporation,
                                   its general partner

                              By: /s/ Nancy M. Haag
                                  -----------------------------
                              Name:  Nancy M. Haag
                              Title:  Assistant Vice President



                                     -iii-
<PAGE>

TENANT:                       CABLETRON SYSTEMS SALES & SERVICE,
                              INC., a Delaware corporation


                              By: /s/ Craig R. Benson
                                  -------------------------------
                              Name:  Craig R. Benson
                              Title:  President, Chief Executive Officer

                                      -iv-
<PAGE>

                               TABLE OF CONTENTS
                               -----------------
<TABLE>
<CAPTION>

                                                                                        Page
                                                                                        ----
<S>                                                                                     <C>

   1.    Definitions And Basic Provisions...........................................     1
   2.    Lease Grant................................................................     1
   3.    Term and Construction......................................................     1
   3.1   Lease Term.................................................................     1
   3.2   Landlord's Construction Obligation.........................................     1
   4.    Rent.......................................................................     1
   4.1   Payment....................................................................     1
   4.2   Operating Costs............................................................     2
   4.3   Tenant's Inspection Right..................................................     4
   5.    Delinquent Payment; Handling Charges.......................................     5
   6.    [INTENTIONALLY DELETED]....................................................     5
   7.    Landlord's Maintenance Obligations.........................................     5
   7.1   Landlord's Obligations.....................................................     5
   7.2   Landlord's Right to Perform Tenant's Obligations...........................     6
   8.    Improvements; Alterations; Repairs; Tenant's Maintenance; and Utilities....     6
   8.1   Improvements: Alterations..................................................     6
   8.2   Repairs; Maintenance.......................................................     7
   8.3   Performance of Work........................................................     7
   8.4   Mechanic's Liens...........................................................     7
   8.5   Utilities..................................................................     8
   9.    Use........................................................................     8
  10.    Assignment and Subletting..................................................     8
  10.1   Transfers..................................................................     8
  10.2   Consent Standards..........................................................     8
  10.3   Requests for Consent.......................................................     9
  10.4   Conditions to Consent......................................................     9
  10.5   Cancellation...............................................................     9
  10.6   Additional Compensation....................................................     9
  10.7   Permitted Transfers........................................................    10
  11.    Insurance; Waivers; Subrogation; Indemnity.................................    11
  11.1   Insurance..................................................................    11
  11.2   Waiver of Negligence.......................................................    11
  11.3   Indemnity..................................................................    11
  11.4   Landlord's Insurance.......................................................    12
  11.5   Blanket Policy.............................................................    12
  11.6   Self Insurance.............................................................    12
  12.    Subordination Attornment; Notice to Landlord's Mortagee....................    13
  12.1   Subordination..............................................................    13
  12.2   Attornment.................................................................    13
  12.3   Notice to Landlord's Mortgagee.............................................    13
  12.4   Landlord's Mortgagee's Protection Provisions...............................    13
  13.    Rules and Regulations......................................................    14
</TABLE>


                                      -v-
<PAGE>

<TABLE>
<CAPTION>

                                                                                       Page
                                                                                       ----
<S>                                                                                     <C>

  14.    Condemnation...............................................................    14
  14.1   Total Taking...............................................................    14
  14.2   Partial Taking-Tenant's Rights.............................................    14
  14.3   Partial Taking-Landlord's Rights...........................................    14
  14.4   Award......................................................................    14
  15.    Fire or Other Casualty.....................................................    15
  15.1   Repair Estimate............................................................    15
  15.2   Landlord's and Tenant's Rights.............................................    15
  15.3   Landlord's Rights..........................................................    15
  15.4   Repair Obligation..........................................................    15
  16.    Personal Property Taxes....................................................    16
  17.    Events of Default..........................................................    16
  18.    Remedies...................................................................    17
  18.1   Termination................................................................    17
  18.2   Enforcement of Lease.......................................................    18
  18.3   Sublessees of Tenant.......................................................    18
  18.4   Efforts to Relet...........................................................    18
  18.5   Mitigation.................................................................    18
  19.    Payment by Tenant; Non-Waiver..............................................    18
  19.1   Payment by Tenant..........................................................    18
  19.2   No Waiver..................................................................    19
  20.    [INTENTIONALLY DELETED]....................................................    19
  21.    Surrender of Premises......................................................    19
  22.    Holding Over...............................................................    20
  23.    Certain Rights Reserved by Landlord........................................    20
  24.    [INTENTIONALLY DELETED]....................................................    20
  25.    Miscellaneous..............................................................    20
  25.1   Landlord Transfer..........................................................    21
  25.2   Landlord's Liability.......................................................    21
  25.3   Force Majeure..............................................................    21
  25.4   Brokerage..................................................................    21
  25.5   Estoppel Certificates......................................................    21
  25.6   Notices....................................................................    22
  25.7   Separability...............................................................    22
  25.8   Amendments; and Binding Effect.............................................    22
  25.9   Quiet Enjoyment............................................................    22
  25.10  No Merger..................................................................    22
  25.11  No Offer...................................................................    22
  25.12  Entire Agreement...........................................................    22
  25.13  Waiver of Jury Trial.......................................................    23
  25.14  Governing Law..............................................................    23
  25.15  Joint and Several Liability................................................    23
  25.16  Financial Reports..........................................................    23
  25.17  Landlord's Fees............................................................    23
  25.18  Attorney Fees..............................................................    23
  25.19  Telecommunications.........................................................    24
</TABLE>

                                     -vi-
<PAGE>

<TABLE>
<CAPTION>

                                                                                       Page
                                                                                       ----
<S>                                                                                     <C>

 25.20   Confidentiality............................................................    24
 25.21   Hazardous Materials........................................................    24
 25.22   Signage....................................................................   245
 25.23   Parking....................................................................    25
 25.24   List of Exhibits...........................................................    25
 26.     Extension Option...........................................................    25
 26.1    Grant of Option............................................................    25
 26.2    Basic Rent.................................................................    25
 26.3    Arbitration................................................................    26
 26.4    Termination of Option......................................................    27
 27.     Rent Abatement.............................................................    27
</TABLE>

TABLE OF EXHIBITS:
------------------

Exhibit A   Outline of Premises
Exhibit B   Legal Description of Project
Exhibit C   Building Rules and Regulations
Exhibit D   Work Letter Agreement
Exhibit F   First Amendment to Lease
Exhibit F   Form of Tenant Estoppel Certificate
Exhibit G   Guaranty

                                     -vii-
<PAGE>

                                     LEASE
                                     -----


     THIS LEASE AGREEMENT (this "Lease") is entered into as of January 6, 1999,
                                 -----
between WMP II Real Estate Limited Partnership, a Delaware limited partnership
("Landlord"), and Cabletron Systems Sales & Service, Inc., a Delaware
  --------
corporation ("Tenant").
              ------

     1. Definitions And Basic Provisions. The definitions and basic provisions
        --------------------------------
set forth in (the "Basic Lease Information") executed by Landlord and Tenant
                   -----------------------
contemporaneously herewith are incorporated herein by reference for all
purposes. Additionally, the following terms shall have the following meanings
when used in the Lease: "Laws" means all federal, state, and local laws, rules
                         ----
and regulations, all court orders, governmental directives, and governmental
orders, and all restrictive covenants affecting the Property, and "Law" shall
                                                                   ---
mean any of the foregoing; "Affiliate" means any person or entity which,
                            ---------
directly or indirectly, through one or more intermediates, controls, is
controlled by, or is under common control with the party in question; "Tenant
                                                                       ------
Party" means any of the following persons: Tenant; any assignees claiming by,
-----
through, or under Tenant; any subtenants claiming by, through, or under Tenant;
any assignees claiming by, through, or under Tenant; and any of their respective
agents, constructors, employees, and invitees; and "including" means including,
                                                    ---------
without limitation.


     2. Lease Grant. Subject to the terms of this Lease, Landlord leases to
        -----------
Tenant, and Tenant leases from Landlord, the Premises.

     3. Term and Construction.
        ---------------------

        3.1 Lease Term. The term of this Lease shall commence on the
            ----------
Commencement Date; provided, however, in the event the Tenant Improvements to be
constructed in the Premises pursuant to Exhibit D attached hereto are completed
                                        ---------
before such date, Tenant shall have the right to occupy the Premises prior to
such Commencement Date, subject to all the provisions of this Lease, except the
obligation to pay Rent; and further provided that Tenant shall have the right to
enter the Premises prior to the completion of such Tenant Improvements for the
purpose of installing equipment and furniture, provided Tenant's access does not
unreasonably interfere with the completion of the construction work in the
Premises.

        3.2 Landlord's Construction Obligation. Landlord's obligation to
            ----------------------------------
construct improvements in the Premises for Tenant's occupancy shall be limited
to those obligations, if any, specifically set forth in Exhibit D hereto.

     4.  Rent.
         ----

        4.1 Payment. Subject to the conditional abatement of Rent contained in
            -------
Section 27 herein, Tenant shall timely pay to Landlord Basic Rent and all
additional sums to

                                      -1-
<PAGE>

be paid by Tenant to Landlord under this Lease (collectively, the "Rent"),
                                                                   ----
without deduction or set-off, at Landlord's address provided for in this Lease
or as otherwise specified by Landlord. Basic Rent, adjusted as herein provided,
shall be payable monthly in advance. One (1) monthly installment of Basic Rent
shall be payable contemporaneously with the execution of this Lease and shall be
applied to the Basic Rent due for the fourth month of the Lease Term;
thereafter, subject to Section 27, Basic Rent shall be payable on the first day
of each month beginning on the first day of the fifth full calendar month of the
Term. The monthly Basic Rent for any partial month at the beginning of the Term
shall equal the product of 1/365 of the annual Basic Rent in effect during the
partial month and the number of days in the partial month from and after the
Commencement Date, and shall be due on the Commencement Date.

        4.2 Operating Costs.
            ---------------

            4.2.1 Tenant shall pay, as "Additional Rent", its Proportionate
                                        ---------------
Share of Operating Costs (defined below). Landlord may make a good faith
estimate of the Additional Rent to be due by Tenant for any calendar year or
part thereof during the Term, and Tenant shall pay to Landlord, on the
Commencement Date and on the first day of each calendar month thereafter, an
amount equal to the estimated Additional Rent for such calendar year or part
thereof divided by the number of months therein. From time to time, but not more
than two (2) times per year, Landlord may estimate and re-estimate the
Additional Rent to be due by Tenant and deliver a copy of the estimate or
re-estimate to Tenant. Thereafter, the monthly installments of Additional Rent
as estimated by Landlord. Any amounts paid based on such an estimate shall be
subject to adjustment as herein provided when actual Operating Costs are
available for each calendar year.

            4.2.2 The term "Operating Costs" shall mean all expenses and
                            ---------------
disbursements (subject to the limitations set forth below) that Landlord incurs
in connection with the ownership, operation, and maintenance of the Project,
determined in accordance with sound accounting principles consistently applied,
including, but not limited to, the following costs: (A) wages and salaries
(including management fees) of all employees engaged (but only to the extent so
engaged) in the operation, maintenance, and security of the Project, including
taxes, insurance and benefits relating thereto; (B) all supplies and materials
used in the operation, maintenance, repair, replacement, and security of the
Project; (C) costs for improvements made to the Project which although capital
in nature, are expected to reduce the normal operating costs of the Project, as
well as capital improvements made in order to comply with any law hereafter
promulgated by any governmental authority, as amortized over the useful economic
life of such improvements in accordance with generally accepted accounting
principles, to the extent applicable; (D) cost of all utilities, except the cost
of utilities reimbursable to Landlord by the Project's tenants other than
pursuant to a provision similar to this Section 4.2; (E) insurance expenses; (F)
repairs, replacements, and general maintenance of the Project; and (G) service
or maintenance contracts with independent contractors for the operation,
maintenance, repair, replacement, or security of the Project (including, without
limitation, alarm service, window cleaning, and elevator maintenance).

                                      -2-
<PAGE>

     Operating Costs shall not include costs for (i) capital improvements made
to the Project other than capital improvements described in Section 4.2.2 (C)
and except for items which are generally considered maintenance and repair
items, such as painting of common areas, replacement of carpet in elevator
lobbies, and the like, which maintenance and repair items shall be amortized
over the useful life of each improvement in accordance with generally accepted
accounting principles to the extent applicable, and to the extent such
maintenance and repair items are considered to be capital in nature by Landlord;
(ii) repair, replacements and general maintenance paid by proceeds of insurance
or by Tenant or other third parties; (iii) interest, amortization or other
payments on loans to Landlord and rental under any ground or underlying lease or
leases; (iv) depreciation; (v) leasing commission; (vi) legal expenses for
services, other than those that benefit the Project tenants generally (e.g., tax
disputes); (vii) renovating or otherwise improving space for occupants of the
Project or vacant space in the Project; (viii) Taxes (defined below); (ix)
income taxes imposes on or measured by the income of Landlord from the operation
of the Project; (x) costs incurred due to violation by Landlord or any tenant of
the terms and conditions of any lease; (xi) advertising and promotional
expenditures; (xii) any fines or penalties incurred due to violations by
Landlord of any governmental rule or authority; (xiii) any costs incurred by
Landlord in the event that the Project does not comply with governmental rules
in effect as of the date of execution of this Lease, unless such non-compliance
is due to the Tenant Improvements to be constructed by Tenant pursuant to
Exhibit D attached hereto, in which event such costs shall be included within
---------
the Tenant Improvement Costs (as defined in Exhibit D); (xiv) the cost of any
items for which the Landlord is actually reimbursed by condemnations proceeds,
insurance carried (or required by this Lease to be carried and not so carried)
or by warranty or for which Landlord is otherwise actually compensated; (xv)
costs for sculpture, paintings, or other objects of art; (xvi) charitable
contributions; (xvii) any costs relating to hazardous materials, asbestos and
the like not resulting from actions of Tenant; (xviii) costs incurred by
Landlord due to the negligence or misconduct of Landlord or its agents,
contractors, licensees and employees, or the violation by Landlord or any
tenants or other occupants of the terms and conditions of any lease of space or
other agreements including this Lease; (xix) wages, salaries or other
compensation paid to any executive employees above the grade of building
superintendent, except that if any such employee performs a service which would
have been performed by an outside consultant, the compensation paid to such
employee for performing such service shall be included in Operating Costs, to
the extent only that the cost of such service does not exceed the competitive
cost of such service had such service been rendered by an outside consultant;
and (xx) any and all costs of Landlord in complying with environmental
regulations including, but not limited to, the costs and expenses of clean-up,
remediation, environmental surveys/assessments, compliance with environmental
laws, consulting fees, treatment and monitoring charges, transportation expenses
and disposal fees, except if such costs are a result of Tenant's use of or
activities in or on the Building.

         The Landlord shall not recover under this Section 4.2 or elsewhere in
this Lease any item of cost more than once.

            4.2.3 Tenant shall also pay its Proportionate Share of the Taxes for
each year and partial year falling within the Term, in the same manner as
provided above for

                                      -3-
<PAGE>

Additional Rent with regard to Operating Costs. "Taxes" shall
                                                 -----
mean taxes, assessments, and governmental charges whether federal, state,
county or municipal, and whether they be by taxing districts or authorities
presently taxing or by others, subsequently created or otherwise, and any other
taxes and assessments attributable to the Project (or its operation), excluding,
however, penalties and interest thereon and federal and state taxes on income
(if the present method of taxation changes so that in lieu of the whole or any
part of any Taxes, there is levied on Landlord a capital tax directly on the
rents received therefrom or a franchise tax, assessment, or charge based, in
whole or in part, upon such rents for the Project, then all such taxes,
assessments, or charges, or the part thereof so based, shall be deemed to be
included within the term "Taxes" for purposes hereof). Taxes shall include the
costs of consultants retained in an effort to lower taxes and all costs incurred
in disputing any taxes or in seeking to lower the tax valuation of the Project.
Notwithstanding the foregoing to the contrary, "Taxes" shall not include any
inheritance, transfer, gift, estate, succession, franchise, corporate, rental,
income or profit taxes, capital levy or excise. Tenant shall not be required to
share in any penalties, interest, late payments, or the like resulting from
Landlord's late payment of taxes.

         4.2.4 By April 1 of each calendar year, or as soon thereafter as
practicable, Landlord shall furnish to Tenant a statement of Operating Costs for
the previous year, adjusted as provided in Section 4.2.5 and of the Taxes for
the previous year (the "Operating Costs and Tax Statement"). If the Operating
                        ---------------------------------
Costs and Tax Statement reveals that Tenant paid more for Operating Costs than
the actual amount for the year for which such statement was prepared, or more
than its actual share of Taxes for such year, then Landlord shall promptly
credit or reimburse Tenant, at Tenant's election, for such excess; likewise, if
Tenant paid less than Tenant's actual Proportionate Share of Additional Rent or
share of Taxes due, then Tenant shall promptly pay Landlord such deficiency.

         4.2.5 With respect to any calendar year or partial calendar year in
which the Project is not occupied to the extent of ninety-five percent (95%) of
the rentable area thereof, the Operating Costs for such period shall, for the
purposes hereof, be increased to the amount which would have been incurred had
the Project been occupied to the extent of ninety-five percent (95%) of the
rentable area thereof.

         4.2.6 Tenant's Proportionate Share of Operating Costs and Taxes shall
be determined by Landlord as a function of the rentable square footage of the
Building alone, or the rentable square footage of the Project, depending on the
nature of the item to be charged. Any items applicable to other buildings within
the Project, or to other portions of the Project which are the same or
substantially similar to items for which Tenant is responsible under this Lease,
and which are determined as a function of the rentable square footage of the
Building, shall not be included in Operating Costs charged to the Project.

         4.3 Tenant's Inspection Right. After giving Landlord thirty (30) days
             -------------------------
prior written notice thereof, Tenant may inspect or audit Landlord's records
relating to Operating Costs and Taxes for the immediately preceding period for
which an annual statement is provided; however, no audit or inspection shall
extend to periods of time before the Commencement Date. If Tenant fails to
object to the calculation of Operating Costs and

                                      -4-
<PAGE>

Taxes on an annual Operating Costs and Tax Statement within sixty (60) days
after the statement has been delivered to Tenant, then Tenant shall have waived
its right to object to the calculation of Operating Costs and Taxes for the year
in question and the calculation of Operating Costs and Taxes set forth on such
statement shall be final. Tenant's audit or inspection shall be conducted only
during business hours reasonably designated by Landlord. Tenant shall pay the
cost of such audit or inspection, including $150.00 per hour of Landlord's or
the Building manager's employee time devoted to such inspection or audit to
reimburse Landlord for its overhead costs allocable to the inspection or audit,
unless the total Operating Costs and Taxes for the time period in question is
determined to be in error by more than five percent (5%) in the aggregate, in
which case Landlord shall pay the audit cost. Tenant may not conduct an
inspection or have an audit performed more than once during any calendar year.
If such inspection or audit reveals that an error was made in the Operating
Costs and Taxes previously charged to Tenant, the Landlord shall refund to
Tenant any overpayment of any such costs, or Tenant shall pay to Landlord any
underpayment of any such costs, as the case may be, within thirty (30) days
after notification thereof. Provided Landlord's accounting for Operating Costs
and Taxes is consistent with the terms of this Agreement, Landlord's good faith
judgment regarding the proper interpretation of this Agreement and the proper
accounting for Operating Costs and Taxes shall be binding on Tenant in
connection with any such audit or inspection. Tenant shall maintain the results
of each such audit or inspection confidential and shall not be permitted to use
any third party to perform such audit or inspection, other than an independent
firm of certified public accountants (A) reasonably acceptable to Landlord, (B)
which is not compensated on a contingency fee basis or in any other manner which
is dependent upon the results of such audit or inspection (and Tenant shall
deliver the fee agreement or other similar evidence of such fee arrangement to
Landlord upon request), and (C) which agrees with Landlord in writing to
maintain the results of such audit or inspection confidential.

         5. Delinquent Payment; Handling Charges. All past due payments required
            ------------------------------------
of Tenant hereunder shall bear interest from the date due until paid at the
lesser of ten percent (10%) per annum or the maximum lawful rate of interest;
additionally, Landlord may charge Tenant a fee equal to five percent (5%) of the
delinquent payment to reimburse Landlord for its cost and inconvenience incurred
as a consequence of Tenant's delinquency; provided, however, Landlord shall not
charge interest or any late fees on Rent payable by Tenant until the sixth (6th)
day after such Rent payment was due hereunder. In no event, however, shall the
charges permitted under this Section 5 or elsewhere in this Lease, to the extent
they are considered to be interest under applicable Law, exceed the maximum
lawful rate of interest.

         6. [INTENTIONALLY DELETED]
             ---------------------

         7. Landlord's Maintenance Obligations.
            ----------------------------------

            7.1 Landlord's Obligations. This Lease is intended to be a net
                ----------------------
lease; accordingly, Landlord's maintenance obligations are limited to the
replacement of the roof and maintenance of the foundation and structural members
of exterior and all load bearing walls of the Buildings within the Project (the
"Building Structure"); Landlord shall not be responsible (1)for any such work
 ------------------
until Tenant notifies Landlord of the need therefor in

                                      -5-
<PAGE>

writing or (2) for alterations to the Building's Structure required by
applicable Law because of Tenant's use of the Premises (which alterations shall
be Tenant's responsibility). Notwithstanding the foregoing to the contrary,
Landlord shall replace the roof of the Building during calendar year 1999 at
Landlord's sole cost and expense. The Building's Structure does not include
skylights, windows, glass or plate glass, doors, special fronts, or office
entries, all of which shall be maintained by Tenant. Landlord's liability for
any defects, repairs, replacement or maintenance for which Landlord is
specifically responsible under this Lease shall be limited to the cost of
performing the work except in the event of active negligence or willful
misconduct by Landlord in the performance of such work. Notwithstanding the
foregoing to the contrary, Landlord shall be obligated to construct all
modifications to the exterior of the Building required as a condition to the
issuance of a Certificate of Occupancy for the Tenant Improvements in the
Premises. Landlord shall deliver the Premises to Tenant in clean condition with
(i) all existing Building systems in good working order, (ii) the roof free of
all leaks, and (iii) all damaged or stained ceiling tiles replaced. Furthermore,
Landlord hereby warrants that the HVAC system servicing the Premises, including
all portable units servicing the computer rooms, shall be in good working order
through and including August 31, 1999. Except as expressly set forth in this
Lease, and subject to reimbursement pursuant to Section 4.2 hereof, Landlord
shall maintain and light the areas, driveways, alleys and grounds surrounding
the Premises in a clean and sanitary condition, consistent with the operation of
a first-class building, including maintenance, repair, and replacement of the
exterior of the Building (including painting), sprinkler systems and sewage
lines, and any items normally associated with the foregoing.

         7.2 Landlord's Right to Perform Tenant's Obligations. In the event
             ------------------------------------------------
Tenant has failed to perform same, and only after ten (10) days' written notice
to Tenant (except in the event of an emergency), Landlord may perform Tenant's
maintenance, repair, and replacement obligations and any other items that are
Tenant's obligation pursuant to Section 8. Tenant shall reimburse Landlord for
the cost incurred in so doing within ten (10) days after being invoiced
therefor.

     8. Improvements; Alterations; Repairs; Tenant's Maintenance; and Utilities.
        -----------------------------------------------------------------------

         8.1 Improvements; Alterations. Except as otherwise provided in
             -------------------------
Exhibit D attached hereto, improvements to the Premises shall be installed at
Tenant's expense only in accordance with plans and specifications which have
been previously submitted to and approved in writing by Landlord. No alterations
or physical additions in or to the Premises may be made without Landlord's prior
written consent, which shall not be unreasonably withheld or delayed; however,
Landlord may withhold its consent to any alteration or addition that would
affect the Building's structure or its HVAC, plumbing, electrical, or mechanical
systems. Tenant shall not paint or install lighting or decorations, signs,
window or door lettering, or advertising media of any type on or about the
Premises without the prior written consent of Landlord, which shall not be
unreasonably withheld or delayed; however, Landlord may withhold its consent to
any such painting or installation which would affect the appearance of the
exterior of the Building or of any common areas of the Building. All
alterations, additions, or improvements made in or upon the Premises shall, at
Landlord's option (exercised by notice to Tenant given (i) at the time Tenant
requests consent to such

                                      -6-
<PAGE>

alterations, additions or improvements, or (ii) at any time if consent to such
alterations, additions or improvements was required but not obtained), either be
removed by Tenant prior to the end of the Term (and Tenant shall repair all
damage caused thereby), or shall remain on the Premises at the end of the Term
without compensation to Tenant. All alterations, additions, and improvements
shall be constructed, maintained, and used by Tenant, at its risk and expense,
in accordance with all laws; Landlord's approval of the plans and specifications
therefor shall not be a representation by Landlord that such alterations,
additions, or improvements comply with any Law. Notwithstanding anything to the
contrary set forth in this Section 8.1, although fifteen (15) days advance
written notice to Landlord is required, Landlord's consent shall not be required
for any alterations, improvements or physical additions proposed by Tenant that
(a) will cost less than Twenty Thousand Dollars ($20,000.00) in each instance to
construct, (b) are non- structural and do not affect the Building's structure or
its HVAC, plumbing, telecommunications, elevator, life-safety, electrical,
mechanical or other basic systems or require a building permit, (c) will not
result in changes to the Premises or Building that are visible from the outside
of the building, and (d) Tenant removes same from the Premises at the end of the
Term if then requested by Landlord.

         8.2 Repairs; Maintenance. Tenant shall maintain all parts of the
             --------------------
Premises in a good condition and promptly make all necessary repairs and
replacements to the Premises, excepting only that work which Landlord is
expressly responsible for pursuant to Section 7.1. Tenant shall maintain the
HVAC, plumbing, electrical, and mechanical systems in the Premises in good
repair and condition in accordance with applicable law and the equipment
manufacturer's suggested service programs. If Landlord so directs, Tenant shall
enter into a preventive maintenance/service contract with a maintenance
contractor approved by Landlord for servicing all air conditioning, heating,
ventilating and other equipment located within or serving the Premises.

         8.3 Performance of Work. All work described in this Section 8 shall be
             -------------------
performed only by Landlord or by licensed contractors and subcontractors who
shall be reasonably approved in writing by Landlord for all improvements that
cost $20,000.00 or more in each instance. Tenant shall cause all contractors and
subcontractors to procure and maintain insurance coverage naming Landlord as an
additional insured against such risks, in such amounts, and with such companies
as Landlord may reasonably require. All such work shall be performed in
accordance with all Laws and in a good and workmanlike manner so as not to
damage the Building (including the Premises, the structural elements, and the
plumbing, electrical lines, or other utility transmission facility). All such
work which may affect the Building's HVAC, electrical, plumbing, other
mechanical systems, or structural elements must be approved by the Building's
engineer of record, at Tenant's expense and, at Landlord's election, must be
performed by Landlord's usual contractor for such work.

         8.4 Mechanic's Liens. Tenant shall not permit any mechanic's liens to
             ----------------
be filed against the Premises or the Building for any work performed, materials
furnished, or obligation incurred by or at the request of Tenant. If such a lien
is filed, then Tenant shall, within ten (10) days after Landlord has delivered
notice of the filing thereof to Tenant, either pay the amount of the lien or
diligently contest such lien and deliver to Landlord a bond or

                                      -7-
<PAGE>

other security reasonably satisfactory to Landlord. If Tenant fails to timely
take either such action, then Landlord may pay the lien claim, and any amounts
so paid, including expenses and interest, shall be paid by Tenant to Landlord
within ten (10) days after Landlord has invoiced Tenant therefor.

         8.5 Utilities. Tenant shall obtain and pay for all water, gas,
             ---------
electricity, heat, telephone, sewer, sprinkler charges and other utilities and
services used at the Premises, together with all taxes, penalties, surcharges,
and maintenance charges pertaining thereto. Landlord may, at Tenant's expense,
separately meter and bill Tenant directly for its use of utility services;
provided Landlord shall not charge more for such utilities than would be charged
Tenant by the public utility company for the same services and in the same
quantity. Landlord shall not be liable for any interruption or failure of
utility service to the Premises unless caused by Landlord's affirmative acts or
active negligence. Any amounts payable by Tenant under this Section shall be due
within twenty (20) days after Tenant's receipt of Landlord's invoice therefor.

         9. Use. Tenant shall continuously occupy and use the Premises only for
            ---
the Permitted Use and shall comply with all Laws relating to the use, condition,
access to, and occupancy of the Premises. The Premises shall not be used for any
use which is illegal, creates extraordinary fire hazards, or results in an
increased rate of insurance on the Building or its contents, or for the storage
of any Hazardous Materials. If, as a direct result of a Tenant Party's acts, the
rate of insurance on the Building or its contents increases, then such acts
shall be an Event of Default, Tenant shall pay to Landlord the amount of such
increase on demand, and acceptance of such payment shall not waive any of
Landlord's other rights. Tenant shall conduct its business and control each
other Tenant Party so as not to create any nuisance or unreasonably interfere
with other tenants or Landlord in its management of the Building.

         10. Assignment and Subletting.
             -------------------------

          10.1 Transfers. Except as provided in Section 10.7, Tenant shall not,
               ---------
without the prior written consent of Landlord, (1) assign, transfer, or encumber
this Lease or any estate or interest herein, whether directly or by operation of
law, (2) permit any other entity to become Tenant hereunder by merger,
consolidation, or other reorganization, (3) if Tenant is an entity other than a
corporation whose stock is publicly traded, permit the transfer of an ownership
interest in Tenant so as to result in a change in the current control of Tenant,
(4) sublet any portion of the Premises, (5) grant any license, concession, or
other right of occupancy of any portion of the Premises, or (6) permit the use
of the Premises by any parties other than Tenant (any of the events listed in
this Section 10.1 being a "Transfer").
                           --------

          10.2 Consent Standards. Landlord shall not unreasonably withhold its
               -----------------
consent to any assignment or subletting of the Premises, provided that the
proposed transferee is creditworthy, will use the Premises for the Permitted Use
(thus, excluding, without limitation, uses where the population density within
the Premises as a whole exceeds one person for each 300 rentable square feet in
the Premises, or where the proposed transferee conducts second or third shift
operations within the Premises, which uses are not

                                      -8-
<PAGE>

within the scope of the Permitted Use) and will not use the Premises in any
manner that would conflict with any exclusive use agreement or other similar
agreement entered into by Landlord with any other tenant of the Building, is not
a governmental entity, or subdivision or agency thereof, and is not another
occupant of the Building or person or entity with whom Landlord is negotiating
to lease space in the Building; otherwise, Landlord may withhold its consent in
its sole discretion.

          10.3 Requests for Consent. If Tenant requests Landlord's consent to a
               --------------------
Transfer, then Tenant shall provide Landlord with a written description of all
terms and conditions of the proposed Transfer, copies of the proposed
documentation, and the following information about the proposed transferee: name
and address; reasonably satisfactory information about its business and business
history; its proposed use of the Premises; banking, financial, and other credit
information; and general references sufficient to enable Landlord to determine
the proposed transferee's creditworthiness and character.

          10.4 Conditions to Consent. Concurrently with Tenant's notice of any
               ---------------------
request for consent to a Transfer, Tenant shall reimburse Landlord immediately
upon request for its reasonable attorneys' fees incurred in connection with
considering any request for consent to a Transfer. If Landlord consents to a
proposed Transfer, then the proposed transferee shall deliver to Landlord a
written agreement whereby it expressly assumes Tenant's obligations hereunder;
however, any transferee of less than all of the space in the Premises shall be
liable only for obligations under this Lease that are properly allocable to the
space subject to the Transfer for the period of the Transfer. Landlord's consent
to a Transfer shall not release Tenant from its obligations under this Lease,
but rather Tenant and its transferee shall be jointly and severally liable
therefor. Landlord's consent to any Transfer shall not waive Landlord's rights
as to any subsequent Transfers. Landlord's consent to any Transfer shall not
waive Landlord's rights as to subsequent Transfers. If an Event of Default
occurs while the Premises or any part thereof are subject to a Transfer, then
Landlord, in addition to its other remedies, may collect directly from such
transferee all rents becoming due to Tenant and apply such rents against Rent.
Tenant authorizes its transferees to make payments of rent directly to Landlord
upon receipt of notice from Landlord to do so. This Section 10.4 does not, and
shall not be construed to, create any rights in favor of any third parties.

          10.5 Cancellation. Landlord may, within ten (10) business days after
               ------------
submission written request for Landlord's consent to an assignment or
subletting, notify Tenant of its intent to cancel this Lease as to the portion
of the Premises proposed to be sublet or assigned as of the date the proposed
Transfer is to be effective. If Landlord cancels this Lease as to any portion of
the Premises, then this Lease shall cease for such portion of the Premises and
Tenant shall pay to Landlord all Rent accrued through the cancellation date
relating to the portion of the Premises covered by the proposed Transfer.
Thereafter, Landlord may lease such portion of the Premises to the prospective
transferee (or to any other person) without liability to Tenant.

          10.6 Additional Compensation. Tenant shall pay to Landlord,
               -----------------------
immediately upon receipt thereof, fifty percent (50%) of the excess of (1) all
compensation

                                      -9-
<PAGE>

received by Tenant for a Transfer less the costs reasonably incurred by Tenant
with unaffiliated third parties in connection with such Transfer (i.e.,
brokerage commissions, tenant finish work, and the like, but in no event to
exceed $5.00 per rentable square foot of the portion of the Premises which is
the subject of the Transfer) over (2) the Rent allocable to the portion of the
Premises covered thereby. This Section 10.6 shall not apply to Permitted
Transfers pursuant to Section 10.7.

          10.7 Permitted Transfers. Notwithstanding Section 10. 1, Tenant may
               -------------------
Transfer all or part of its interest in this Lease or all or part of the
Premises (a "Permitted Transfer") to the following types of entities (a
             ------------------
"Permitted Transferee") without the written consent of Landlord:
 --------------------

               10.7.1 An Affiliate of Tenant;

               10.7.2 Any corporation, limited partnership, limited liability
partnership, limited liability company or other business entity in which or with
which Tenant, or its corporate successors or assigns, is merged or consolidated,
in accordance with applicable statutory provisions governing merger and
consolidation of business entities, so long as (A) Tenant's obligations
hereunder are assumed by the entity surviving such merger or created by such
consolidation; and (B) the Tangible Net Worth of the surviving or created entity
is not less than the Tangible Net Worth of Tenant as of the date hereof; or

               10.7.3 Any corporation, limited partnership, limited liability
partnership, limited liability company or other business entity acquiring all or
substantially all of Tenant's assets if such entity's Tangible Net Worth after
such acquisition is not less than the Tangible Net Worth of Tenant as of the
date hereof.

Tenant shall promptly notify Landlord of any such Permitted Transfer. Tenant
shall remain liable for the performance of all of the obligations of Tenant
hereunder, or if Tenant no longer exists because of a merger, consolidation, or
acquisition, the surviving or acquiring entity shall expressly assume in writing
the obligations of Tenant hereunder. Additionally, the Permitted Transferee
shall comply with all of the terms and conditions of this Lease, including the
Permitted Use, and the use of the Premises by the Permitted Transferee may not
violate any other agreements affecting the Premises, the Building, Landlord or
other tenants of the Building.  At least thirty (30) days after the effective
date of any Permitted Transfer, Tenant agrees to furnish Landlord with copies of
the instrument effecting any of the foregoing Transfers and documentation
establishing Tenant's satisfaction of the requirements set forth above
applicable to any such Transfer.  The occurrence of a Permitted Transfer shall
not waive Landlord's rights as to any subsequent Transfers.  "Tangible Net
                                                              ------------
Worth" means the excess of total assets over total liabilities, in each case as
-----
determined in accordance with generally accepted accounting principles
consistently applied ("GAAP"), excluding, however, from the determination of
                       ----
total assets all assets which would be classified as intangible assets under
GAAP including, without limitation, goodwill, licenses, patents, trademarks,
trade names, copyrights, and franchises.  Any subsequent Transfer by a Permitted
Transferee shall be subject to Landlord's prior written consent (which Landlord
may grant or deny in its sole discretion).

                                      -10-
<PAGE>

        11. Insurance; Waivers; Subrogation; Indemnity.
            ------------------------------------------

             11.1 Insurance. Tenant shall maintain throughout the Term the
                  ---------
following insurance policies: (1) commercial general liability insurance in
amounts of $3,000,000.00 per occurrence, or such other amounts as Landlord may
from time to time reasonably require, insuring Tenant against all liability for
injury to or death of a person or persons or damage to property arising from the
use and occupancy of the Premises, (2) insurance covering the full value of
Tenant's property and improvements, and other property (including property of
others) in the Premises, (3) contractual liability insurance sufficient to cover
Tenant's indemnity obligations hereunder (but only if such contractual liability
is not already included in Tenant's commercial general liability insurance
policy), (4) worker's compensation insurance, and (5) business interruption
insurance. Landlord, Landlord's agents and their respective Affiliates shall be
added as additional insureds on Tenant's commercial general liability policy.
Tenant's insurance shall provide primary coverage to Landlord when any policy
issued to Landlord provides duplicate or similar coverage, and in such
circumstance Landlord's policy will be excess over Tenant's policy. Tenant shall
furnish to Landlord certificates of such insurance and such other reasonable
evidence satisfactory to Landlord of the maintenance of all insurance coverages
required hereunder, and Tenant shall obtain a written obligation on the part of
each insurance company to notify Landlord at least thirty (30) days before
cancellation or a material change of any such insurance policies, provided
comparable insurance is not obtained from another carrier, of which event
Landlord shall be notified immediately. All such insurance policies shall be in
form, and issued by companies, reasonably satisfactory to Landlord.
Notwithstanding the foregoing, Tenant may elect to self insure for the worker's
compensation insurance listed above, but only so long as a valid and current
Certificate of Consent to Self-Insure has been issued by the State of California
Department of Industrial Relations covering all the workers in the Premises and
a copy of same has been delivered to Landlord.

             11.2 Waiver of Negligence; No Subrogation. Landlord and Tenant each
                  ------------------------------------
waives any claim it might have against the other for any injury to or death of
any person or persons or damage to or theft, destruction, loss, or loss of use
of any property (a "Loss"), to the extent the same is insured against under any
                    ----
property insurance policy that covers the Building, the Premises, Landlord's or
Tenant's fixtures, personal property, leasehold improvements, or business
interruption, or, in the case of Tenant's waiver, is required to be insured
against under the terms hereof, regardless of whether the negligence of the
other party caused such Loss; however, Landlord's waiver shall not include any
deductible amounts on insurance policies carried by Landlord. Each party shall
cause its insurance carrier to endorse the property policy waiving the carrier's
rights of recovery under subrogation or otherwise against the other party.

             11.3 Indemnity. Subject to Section 11.2, Tenant shall protect,
                  ---------
defend, indemnify, and hold harmless Landlord and its representatives and agents
from and against all claims, demands, liabilities, causes of action, suits,
judgments, damages, and expenses (including reasonable attorneys' fees) arising
from (1) any Loss arising from any occurrence on the Premises (other than any
Loss arising out of a breach of Tenant's obligations under

                                      -11-
<PAGE>

Section 25.21, which shall be subject to the indemnity in such Section), or (2)
Tenant's failure to perform its obligations under this Lease, even though caused
or alleged to be caused by the negligence or fault of Landlord or its agents
(other than a Loss arising from the gross negligence of Landlord or its agents).
This indemnity is intended to indemnify Landlord and its agents against the
consequences of their own negligence when Landlord or its agents are jointly,
comparatively, contributively, or concurrently negligent with Tenant. Subject to
Section 11.2, Landlord shall protect, defend, indemnify and hold harmless Tenant
and its agents from and against all claims, demands, liabilities, causes of
action, suits, judgments and expenses (including reasonable attorney fees) for
any Loss arising from any occurrence in the Project's common areas, even though
caused or alleged to be caused by the negligence or fault of Tenant or its
agents (other than a Loss arising from the gross negligence of Tenant or its
agents). This indemnity is intended to indemnify Tenant and its agents against
the consequences of their own negligence when Tenant or its agents are jointly,
comparatively, contributively, or concurrently negligent with Landlord. The
indemnities set forth in this Section 11.3 shall survive termination or
expiration of this Lease. If any proceeding is filed for which indemnity is
required hereunder, the indemnifying party agrees, upon request therefor, to
defend the indemnified party in such proceeding at its sole cost utilizing
counsel of its own selection reasonably satisfactory to the indemnified party.

             11.4 Landlord's Insurance. Throughout the Term of this Lease,
                  --------------------
Landlord shall maintain, as a minimum, the following insurance policies: (1)
fire and extended risk insurance covering at least ninety percent (90%) of the
Building's replacement value, and (2) commercial general liability insurance in
an amount of not less than Three Million Dollars ($3,000,000.00). Upon Tenant's
written request (but not more than once in any twelve month period), Landlord
shall provide to Tenant a copy of the insurance certificate evidencing such
coverage. The cost of all insurance carried by Landlord with respect to the
Building shall be included in Operating Costs.


             11.5 Blanket Policy. The insurance outlined in Section 11.1 may be
                  --------------
maintained by Tenant under a so-called "blanket policy" covering the Premises
as well as other premises of Tenant, provided that Tenant shall furnish Landlord
with evidence satisfactory to Landlord of the existence of such blanket policy
and that such blanket policy specifically includes the Premises and that the
aforesaid minimum limits apply to each occurrence covered by such blanket policy
and afford the same protection on a per location basis as would be provided
under an individual policy meeting the requirements thereof.

             11.6 Self Insurance. Notwithstanding the foregoing, Tenant shall be
                  --------------
permitted to self-insure its plate glass and its property and improvements in
the Premises against any such Loss. During all periods in which Tenant so
self-insures any of the same, the rights and obligations of Landlord and Tenant
shall remain the same as if Tenant shall have purchased and kept in force
thereon insurance from an independent, institutional insurer of recognized
responsibility, and, without limitation, the provisions of Section 11.2 of this
Lease shall remain in full force and applicable. Tenant represents by so
self-insuring the above that Tenant then is financially able to absorb any loss
thereto without significant

                                     -12-
<PAGE>

reduction of available capital or any other material, adverse effect on Tenant
or its business operations.

         12. Subordination Attornment; Notice to Landlord's Mortagee.
             -------------------------------------------------------

             12.1 Subordination. This Lease shall be subordinate to any deed of
                  -------------
trust, mortgage, or other security instrument, or any ground lease, master
lease, or primary lease, that now or hereafter covers all or any part of the
Premises (the mortgagee under any such mortgage or the lessor under any such
lease is referred to herein as a "Landlord's Mortgagee"). Notwithstanding the
                                  ---------- ---------
foregoing to the contrary, no such subordination shall be effective unless and
until Tenant has received a non- disturbance agreement from Landlord's Mortgagee
providing that in the event of a foreclosure or transfer in lieu thereof,
Tenant's use, possession, or enjoyment of the Premises shall not be disturbed,
and this Lease shall continue in full force and effect so long as Tenant is not
in default hereunder. Landlord shall obtain a Subordination, Non-Disturbance,
Attornment Agreement ("SNDA") from the current Landlord's Mortgagee within
                       ----
sixty (60) days after the Commencement Date. Any Landlord's Mortgagee may elect,
at any time, unilaterally, to make this Lease superior to its mortgage, ground
lease, or other interest in the Premises by so notifying Tenant in writing.

             12.2 Attornment. Tenant shall attorn to any party succeeding to
                  ----------
Landlord's interest in the Premises, whether by purchase, foreclosure, deed in
lieu of foreclosure, power of sale, termination of lease, or otherwise, upon
such party's request, and shall execute such agreements confirming such
attornment as such party may reasonably request.

             12.3 Notice to Landlord's Mortgagee. Tenant shall not seek to
                  ------------------------------
enforce any remedy it may have for any default on the part of Landlord without
first giving written notice by certified mail, return receipt requested,
specifying the default in reasonable detail, to any Landlord's Mortgagee whose
address has been given to Tenant, and affording such Landlord's Mortgagee a
reasonable opportunity to perform Landlord's obligations hereunder.

             12.4 Landlord's Mortgagee's Protection Provisions. If Landlord's
                  --------------------------------------------
Mortgagee shall succeed to the interest of Landlord under this Lease, Landlord's
Mortgagee shall not be: (1) liable for any act or omission of any prior lessor
(including Landlord); (2) bound by any rent or additional rent or advance rent
which Tenant might have paid for more than the current month to any prior lessor
(including Landlord), and all such rent shall remain due and owing,
notwithstanding such advance payment; (3) bound by any security or advance
rental deposit made by Tenant which is not delivered or paid over to Landlord's
Mortgagee and with respect to which Tenant shall look solely to Landlord for
refund or reimbursement; (4) subject to the defenses which Tenant might have
against any prior lessor (including Landlord); and (5) subject to the offsets
which Tenant might have against any prior lessor (including Landlord) except for
those offset rights which (A) are expressly provided in this Lease, (B) relate
to periods of time following the acquisition of the Building by Landlord's
Mortgagee, and (C) Tenant has provided written notice to Landlord's Mortgagee
and provided Landlord's Mortgagee a reasonable opportunity to cure the event
giving rise to such offset event. Landlord's Mortgagee shall have no liability
or responsibility

                                      -13-
<PAGE>

under or pursuant to the terms of this Lease or otherwise after it ceases to own
an interest in the Building. Nothing in this Lease shall be construed to require
Landlord's Mortgagee to see to the application of the proceeds of any loan, and
Tenant's agreements set forth herein shall not be impaired on account of any
modification of the documents evidencing and securing any loan.

       13. Rules and Regulations. Tenant shall comply with the rules and
           ---------------------
regulations of the Building which are attached hereto as Exhibit C, provided
                                                         ---------
same are enforced by Landlord in a non-discriminatory fashion.
Landlord may, from time to time, change such rules and regulations for the
safety, care, or cleanliness of the Building and related facilities, provided
that such changes are generally applicable to all similar tenants of the
Building and will not unreasonably interfere with Tenant's use of the Premises.
Provided Tenant has notice of same, Tenant shall be responsible for the
compliance with such rules and regulations by each Tenant Party.

       14. Condemnation.
           ------------

             14.1 Total Taking. If the entire Building or Premises are taken by
                  ------------
right of eminent domain or conveyed in lieu thereof (a "Taking"), this Lease
                                                        ------
shall terminate as of the date of the Taking.

             14.2 Partial Taking-Tenant's Rights. If any part of the Building
                  ------------------------------
becomes subject to a Taking and such Taking will prevent Tenant from conducting
its business in the Premises in a manner reasonably comparable to that conducted
immediately before such Taking for a period of more than one hundred eighty
(180) days, then Tenant may terminate this Lease as of the date of such Taking
by giving written notice to Landlord within thirty (30) days after the Taking,
and Rent shall be apportioned as of the date of such Taking. If Tenant does not
terminate this Lease, then Rent shall be abated on a reasonable basis as to that
portion of the Premises rendered untenantable by the Taking.

             14.3 Partial Taking-Landlord's Rights. If any material portion, but
                  --------------------------------
less than all, of the Building becomes subject to a Taking, or if Landlord is
required to pay any of the proceeds received for a Taking to a Landlord's
Mortgagee, then Landlord may terminate this Lease by delivering written notice
thereof to Tenant within thirty (30) days after such Taking, and Rent shall be
apportioned as of the date of such Taking. If Landlord does not so terminate
this Lease, then this Lease will continue, but if any portion of the Premises
has been taken, Rent shall abate as provided in the last sentence of Section
14.2.

             14.4 Award. If any Taking occurs, then Landlord shall receive the
                  -----
entire award or other compensation for the land on which the Building is
situated, the Building, and other improvements taken, and Tenant may separately
pursue a claim (to the extent it will not reduce Landlord's award) against the
condemnor for the value of Tenant's improvements or alterations made to the
Premises by Tenant which Tenant has the right to remove from the Premises
pursuant to this Lease but elects not to remove, or if Tenant elects to remove
any such improvements or alterations, the value of the reasonable removal and
relocation of such

                                      -14-
<PAGE>

improvements or alterations, the value of Tenant's personal property which
Tenant is entitled to remove under this Lease, moving costs, and loss of
business.

        15.  Fire or Other Casualty.
             ----------------------

             15.1 Repair Estimate. If the Premises or the Building are damaged
                  ---------------
by fire or other casualty (a "Casualty"), Landlord shall, within sixty (60) days
                              --------
after such Casualty, deliver to Tenant a good faith estimate (the "Damage
                                                                   ------
Notice") of the time needed to repair the damage caused by such Casualty.
------

             15.2 Landlord's and Tenant's Rights. If a material portion of the
                  ------------------------------
Premises or the Building is damaged by Casualty such that Tenant is prevented
from conducting its business in the Premises in a manner reasonably comparable
to that conducted immediately before such Casualty and Landlord estimates that
the damage caused thereby cannot be repaired within one hundred eighty (180)
days after the Casualty, then Tenant may terminate this Lease by delivering
written notice to Landlord of its election to terminate within thirty (30) days
after the Damage Notice has been delivered to Tenant. If Tenant does not so
timely terminate this Lease, then (subject to Section 15.3) Landlord shall
repair the Building or the Premises, as the case may be, as provided below, and
Rent for the portion of the Premises rendered untenantable by the damage shall
be abated on a reasonable basis from the date of damage until the completion of
the repair, unless a Tenant Party caused such damage, in which case, Tenant
shall continue to pay Rent without abatement.

             15.3 Landlord's Rights. If a Casualty damages a material portion of
                  -----------------
the Building, and Landlord makes a commercially reasonable, good faith
determination that restoring the Premises would be uneconomical, or if Landlord
is required to pay any insurance proceeds arising out of the Casualty to a
Landlord's Mortgagee, then Landlord may terminate this Lease by giving written
notice of its election to terminate within thirty (30) days after the Damage
Notice has been delivered to Tenant, and Basic Rent and Additional Rent shall be
abated as of the date of the Casualty.

             15.4 Repair Obligation. If neither party elects to terminate this
                  -----------------
Lease following a Casualty, then Landlord shall, within a reasonable time after
such Casualty, begin to repair the Building and the Premises and shall proceed
with all due diligence to restore the Building and Premises to substantially the
same condition as they existed immediately before such Casualty; however,
Landlord shall not be required to repair or replace any of the furniture,
equipment, fixtures, and other improvements which may have been placed by, or at
the request of, Tenant or other occupants in the building or the Premises, and
Landlord's obligation to repair or restore the Building or Premises shall be
limited to the extent of the insurance proceeds actually received by Landlord
for the Casualty in question. In the event Landlord is unable to restore the
Building and Premises as set forth in this Section 15.4 within sixty (60) days
after the date Landlord estimated in the Damage Notice as the date the repairs
would be completed (which time period shall be subject to extension pursuant to
the provisions of Section 25.3 entitled "Force Majeure," and which date, as
extended, shall be referred to as the "Required Restoration Date"), then Tenant
may terminate this Lease by delivery of written notice of termination to
Landlord within (and only

                                      -15-
<PAGE>

within) twenty (20) days following the Required Restoration Date, which
termination shall be effective as of the date of the Casualty.

        16. Personal Property Taxes. Tenant shall be liable for all taxes
            -----------------------
levied or assessed against personal property, furniture, or fixtures placed by
Tenant in the Premises. If any taxes for which Tenant is liable are levied or
assessed against Landlord or Landlord's property and Landlord elects to pay the
same, or if the assessed value of Landlord's property is increased by inclusion
of such personal property, furniture or fixtures and Landlord elects to pay the
taxes based on such increase, then Tenant shall pay to Landlord, upon demand,
the part of such taxes for which Tenant is primarily liable hereunder; however,
Landlord shall not pay such amount if Tenant notifies Landlord that it will
contest the validity or amount of such taxes before Landlord makes such payment,
and thereafter diligently proceeds with such contest in accordance with law and
if the non- payment thereof does not pose a threat of lien or other cloud on
Landlord's title to the Building or of loss or seizure of the Building or
interest of Landlord therein.

        17. Events of Default. Each of the following occurrences shall be
            -----------------
an "Event of Default:"
    ----------------

             17.1 Tenant's failure to pay Rent within five (5) days after
Landlord has delivered notice to Tenant that the same is due; however, an Event
of Default shall occur hereunder without any obligation of Landlord to give any
notice if Landlord has given Tenant written notice under this Section 17.1 on
more than two occasions during the twelve (12) month interval preceding such
failure by Tenant;

             17.2 Tenant fails to comply with the Permitted Use set forth herein
and such failure continues for a period of ten (10) days after Landlord has
delivered to Tenant written notice thereof;

             17.3 Tenant fails to provide any estoppel certificate within the
time period required under Section 25.5 and such failure shall continue for five
(5) days after written notice thereof from Landlord to Tenant;

             17.4 Tenant's failure to perform, comply with, or observe any other
agreement or obligation of Tenant under this Lease and the continuance of such
failure for a period of more than thirty (30) days after Landlord has delivered
to Tenant written notice thereof (any such notice shall be in lieu of, and not
in addition to, any notice required under California Code of Civil Procedure
Section 1161 or any similar or successor law); however, if the cure of such
failure is not capable of completion within such thirty (30) day period, then
the Tenant shall be entitled to such time period as is reasonably required to
complete such cure provided (i) the Tenant commences such cure within said
thirty (30) days and thereafter prosecutes such cure to completion with all due
diligence, and (ii) the Tenant sends to the Landlord, once a month, a written
report detailing the status of its efforts to cure such default; and

                                     -16-
<PAGE>

             17.5 The filing of a petition by or against Tenant (the term

"Tenant" shall include, for the purpose of this Section 17.6, any guarantor of
 ------
Tenant's obligations hereunder) (1) in any bankruptcy or other insolvency
proceeding; (2) seeking any relief under any state or federal debtor relief law;
(3) for the appointment of a liquidator or receiver for all or substantially all
of Tenant's property or for Tenant's interest in this Lease; or (4) for the
reorganization or modification of Tenant's capital structure; however, if such a
petition is filed against Tenant, then such filing shall not be an Event of
Default unless Tenant fails to have the proceedings initiated by such petition
dismissed within ninety (90) days after the filing thereof.

        18. Remedies. Upon any Event of Default, Landlord may, in addition
            --------
to all other rights and remedies afforded Landlord hereunder or by law or
equity, take any of the following actions each and all of which shall be
cumulative and non-exclusive, without notice or demand whatsoever;

            18.1  Termination. Terminate this Lease in which event Tenant shall
                  -----------
immediately surrender the 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 Premises
and expel or remove Tenant and any other person who may be occupying the
Premises or any part thereof, without being liable for prosecution or any claim
or damages therefor; and Landlord may recover from Tenant the following:

                18.1.1 The worth at the time of award of any unpaid rent which
has been earned at the time of such termination; plus

                18.1.2 The worth at the time of award of the amount by which the
unpaid rent which would have been earned after termination until the time of
award exceeds the amount of such rental loss that Tenant proves could have been
reasonably avoided; plus

                18.1.3 The worth at the time or award of the amount by which the
unpaid rent for the balance of the Lease Term after the time of award exceeds
the amount of such rental loss that Tenant proves could have been reasonably
avoided; plus

                18.1.4 Any other amount necessary to compensate Landlord for all
the actual out-of-pocket expenses directly incurred due to Tenant's failure to
perform its obligations under this Lease specifically including, but not limited
to, brokerage commissions and advertising expenses incurred, expenses of
remodeling the Premises or any portion thereof for a new tenant, whether for the
same or a different use, and any special concessions made to obtain a new
tenant; and

                18.1.5 At Landlord's election, such other amounts in addition to
or in lieu of the foregoing as may be permitted from time to time by applicable
law.

     The term "rent" as used in this Section 18.1 shall be deemed to be and to
mean all sums of every nature required to be paid by Tenant, pursuant to the
terms of this Lease,

                                      -17-
<PAGE>

whether to Landlord or to others. As used in Sections 18.1.1 and 18.1.2 above,
the "worth at the time of award" shall be computed by allowing interest at the
Interest Rate set forth in Section 5 of this Lease, but in no case greater than
the maximum amount of such interest permitted by law. As used in Section 18.1.3
above, the "worth at the time of award" shall be 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 (1%).

                18.2 Enforcement of Lease. Landlord shall have the remedy
                     --------------------
described in 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 the right to sublet or assign, subject only to reasonable
limitations). Accordingly, if Landlord does not elect to terminate this Lease on
account of any Event of Default by Tenant, Landlord may, from time to time,
without terminating this Lease, enforce all of its rights and remedies under
this Lease, including the right to recover all rent as it becomes due.

                18.3 Sublessees of Tenant. Whether or not Landlord elects to
                     --------------------
terminate this Lease on account of any default by Tenant, as set forth in this
Section 18, Landlord shall have the right to terminate any and all subleases,
licenses, concessions or other consensual arrangements for possession entered
into by Tenant and affecting the Premises or may, in Landlord's sole discretion,
succeed to Tenant's interest in such subleases, licenses, concessions or
arrangements. In the event of Landlord's election to succeed to Tenant's
interest in any such subleases, licenses, concessions or arrangements, Tenant
shall, as of the date of notice by Landlord of such election, have no further
right to or interest in the rent or other consideration receivable thereunder.

                18.4 Efforts to Relet. For the purposes of this Section 18,
                     ----------------
Tenant's right to possession shall not be deemed to have been terminated by
efforts of Landlord to relet the Premises, by its acts of maintenance or
preservation with respect to the Premises, or by appointment of a receiver to
protect Landlord's interests hereunder. The foregoing enumeration is not
exhaustive, but merely illustrative of acts which may be performed by Landlord
without terminating Tenant's right to possession.

                18.5 Mitigation. In the event Landlord terminates this Lease or
                     ----------
otherwise re-enters the Premises following a default or Event of Default by
Tenant, Landlord shall use its commercially reasonable efforts to re-let the
Premises for the account of Tenant at the then current market rate and upon such
other terms and provisions as are commercially reasonable under the
circumstances, and consistent with Landlord's practices regarding other vacant
space in the Project.

           19.  Payment by Tenant; Non-Waiver.
                -----------------------------

                19.1 Payment by Tenant. Upon any Event of Default, Tenant shall
                     -----------------
pay to Landlord all actual, out-of- pocket costs incurred by Landlord (including
court costs and reasonable attorneys' fees and expenses) in (1) obtaining
possession of the Premises, (2) removing and storing Tenant's or any other
occupant's property, (3) repairing, restoring, altering, remodeling, or
otherwise putting the Premises into the condition required by market

                                      -18-
<PAGE>

conditions then prevailing so as to be reasonably acceptable to a new tenant as
reasonably determined by Landlord, (4) if Tenant is dispossessed of the Premises
and this Lease is not terminated, reletting all or any part of the Premises
(including brokerage commissions, cost of tenant finish work, and other costs
incidental to such reletting), (5) performing Tenant's obligations which Tenant
failed to perform, and (6) enforcing, or advising Landlord of, its rights,
remedies, and recourses arising out of the Event of Default. To the full extent
permitted by law, Landlord and Tenant agree the federal and state courts of the
state where the Premises are located shall have exclusive jurisdiction over any
matter relating to or arising from this Lease and the parties' rights and
obligations under this Lease.

                19.2 No Waiver. Landlord's acceptance of Rent following an Event
                     ---------
of Default shall not waive Landlord's rights regarding such Event of Default. No
waiver by Landlord of any violation or breach of any of the terms contained
herein shall waive Landlord's rights regarding any future violation of such
term. Landlord's acceptance of any partial payment of Rent shall not waive
Landlord's rights with regard to the remaining portion of the Rent that is due,
regardless of any endorsement or other statement on any instrument delivered in
payment of Rent or any writing delivered in connection therewith; accordingly,
Landlord's acceptance of a partial payment of Rent shall not constitute an
accord and satisfaction of the full amount of the Rent that is due.

                20. [INTENTIONALLY DELETED].
                     ---------------------

                21. Surrender of Premises. No act by Landlord shall be deemed an
                    ---------------------
acceptance of a surrender of the Premises, and no agreement to accept a
surrender of the Premises shall be valid unless it is in writing and signed by
Landlord. At the expiration or termination of this Lease, Tenant shall deliver
to Landlord the Premises with all improvements located therein in good repair
and condition, free of Hazardous Materials placed on the Premises during the
Term, broom-clean, reasonable wear and tear (and condemnation and Casualty
damage not caused by Tenant, as to which Sections 14 and 15 shall control)
excepted, and shall deliver to Landlord all keys to the Premises. Provided that
Tenant has performed all of its obligations hereunder, Tenant may remove all
unattached trade fixtures, furniture, and personal property placed in the
Premises or elsewhere in the Building by Tenant (but Tenant may not remove any
such item which was paid for, in whole or in part, by Landlord or any wiring or
cabling unless Landlord requires such removal). Additionally, at Landlord's
option, Tenant shall remove such alterations, additions, improvements, trade
fixtures, personal property, equipment, wiring, cabling, and furniture as
Landlord may request, provided such request was made (i) at the time Landlord
gave its consent to such alterations, additions or improvements, or (ii) at any
time if consent to such alterations, additions or improvements was required but
not obtained; however, Tenant shall not be required to remove any addition or
improvement to the Premises if Landlord has specifically agreed in writing that
the improvement or addition in question need not be removed. Tenant shall repair
all damage caused by such removal. All items not so removed shall, at Landlord's
option, be deemed to have been abandoned by Tenant and may be appropriated,
sold, stored, destroyed, or otherwise disposed of by Landlord without notice to
Tenant and without any obligation to account for such items. The provisions of
this Section 21 shall survive the end of the Term.

                                    -19-
<PAGE>

        22. Holding Over. If Tenant fails to vacate the Premises at the end of
            ------------
the Term, then Tenant shall be a tenant at will and, in addition to all other
damages and remedies to which Landlord may be entitled for such holding over,
Tenant shall pay, in addition to the other Rent, a daily Basic Rent equal to one
hundred fifty percent (150%) of the daily Basic Rent payable during the last
month of the Term. The provisions of this Section 22 shall not be deemed to
limit or constitute a waiver of any other rights or remedies of Landlord
provided herein or at law. If Tenant fails to surrender the Premises upon the
termination or expiration of this Lease, in addition to any other liabilities to
Landlord accruing therefrom, Tenant shall protect, defend, indemnify and hold
Landlord harmless from all loss, costs (including reasonable attorney fees) and
liability resulting from such failure, including, without limiting the
generality of the foregoing, any claims made by any succeeding tenant founded
upon such failure to surrender, and any lost profits to Landlord resulting
therefrom.

        23. Certain Rights Reserved by Landlord. Provided that the exercise of
            -----------------------------------
such rights does not unreasonably interfere with Tenant's use and occupancy of
the Premises, Landlord shall have the following rights:

            23.1 To decorate and to make inspections, repairs, alterations,
additions, changes, or improvements, whether structural or otherwise, in and
about the Building, or any part thereof; to enter upon the Premises (after
giving the Tenant reasonable notice thereof, which may be oral notice, except in
cases of real or apparent emergency, in which case no notice shall be required)
and, during the continuance of any such work, to temporarily close doors,
entryways, public space, and corridors in the Building; to interrupt or
temporarily suspend Building services and facilities; and to change the name of
the Building; and in the event the Building is occupied by more than one tenant
(not including subtenants), to change the arrangements and location of entrances
or passageways, doors, and doorways, corridors, elevators, stairs, restrooms or
other public parts of the Building;

            23.2 To take such reasonable measures as Landlord deems advisable
for the security of the Building and its occupants; evacuating the Building for
cause, suspected cause, or for drill purposes; temporarily denying access to the
Building; and closing the Building after normal business hours and on Sundays
and holidays, subject, however, to Tenant's right to enter when the Building is
closed after normal business hours under such reasonable regulations as Landlord
may prescribe from time to time; provided, however, so long as it is safe to
enter the Building, Tenant shall have access to the Building twenty-four (24)
hours per day, seven (7) days per week, subject to Landlord's reasonable
regulations; and

            23.3 To enter the Premises at reasonable hours to show the Premises
to prospective purchasers, lenders, or, during the last twelve (12) months of
the Term, tenants.

        24. [INTENTIONALLY DELETED]
             ---------------------

        25. Miscellaneous
            -------------

                                      -20-
<PAGE>

            25.1 Landlord Transfer. Landlord may transfer any portion of the
                 -----------------
Building and any of its rights under this Lease. If Landlord assigns its rights
under this Lease, then Landlord shall thereby be released from any further
obligations hereunder arising after the date of transfer, provided that the
assignee assumes Landlord's obligations hereunder in writing. Landlord or its
assignee shall notify Tenant of such transfer.

            25.2 Landlord's Liability. The liability of Landlord (and its
                 --------------------
partners, shareholders, or members) to Tenant for any default by Landlord under
the terms of this Lease shall be limited to Tenant's actual direct, but not
consequential, damages therefor and shall be recoverable only from the interest
of Landlord in the Building, and Landlord (and its partners, shareholders, or
members) shall not be personally liable for any deficiency. This Section shall
not limit any remedies which Tenant may have for Landlord's defaults which do
not involve the personal liability of Landlord.

            25.3 Force Majeure. Other than for Tenant's obligations under this
                 -------------
Lease that can be performed by the payment of money (e.g., payment of Rent and
maintenance of insurance), whenever a period of time is herein prescribed for
action to be taken by either party hereto, such party shall not be liable or
responsible for, and there shall be excluded from the computation of any such
period of time, any delays due to strikes, riots, acts of God, shortages of
labor or materials, war, governmental laws, regulations, or restrictions, or any
other causes of any kind whatsoever which are beyond the control of such party.

            25.4 Brokerage. Neither Landlord nor Tenant has dealt with any
                 ---------
broker or agent in connection with the negotiation or execution of this Lease,
other than Landlord's Broker (Colliers Parrish International, Inc.-C. Fordyce/M.
Rosendin), and Tenant's Broker (BT Commercial Real Estate-M. Conner and RM
Bradley-C. Batchelder). Landlord shall pay Landlord's Broker's commission.
Landlord's Broker may share the commission with Tenant's Broker, if any, but the
payment of the commission to Landlord's Broker by Landlord shall satisfy any and
all obligations of Landlord for payment of any real estate commissions
hereunder. Tenant and Landlord shall each indemnify the other against all costs,
expenses, attorneys' fees, and other liability for commissions or other
compensation claimed by any broker or agent claiming the same by, through, or
under the indemnifying party.

            25.5 Estoppel Certificates. From time to time, Tenant shall furnish
                 ---------------------
to any party designated by Landlord, within fourteen (14) days after Landlord
has made a request therefor, a certificate signed by Tenant confirming and
containing such factual certifications and representations as to this Lease as
Landlord may reasonably request. Unless otherwise required by Landlord's
Mortgagee or a prospective purchaser or mortgagee of the Building, the initial
form of estoppel certificate to be signed by Tenant is attached hereto as
Exhibit F. Whenever the Tenant so requests in connection with any merger,
acquisition, or like transaction involving Tenant, Tenant's parent company, or
Tenant's affiliated company, Landlord shall promptly, and without cost to
Tenant, execute, acknowledge and deliver to Tenant, and/or any other person
designated by Tenant, a written estoppel certificate prepared by Tenant with
respect to the Premises in form and substance reasonably satisfactory to
Landlord.

                                      -21-
<PAGE>

            25.6 Notices. All notices and other communications given pursuant to
                 -------
this Lease shall be in writing and shall be (1) mailed by first class, United
States Mail, postage prepaid, certified, with return receipt requested, and
addressed to the parties hereto at the address specified in the Basic Lease
Information, (2) hand delivered to the intended address, (3) sent by a
nationally recognized overnight courier service, or (4) sent by facsimile
transmission during normal business hours followed by a confirmatory letter sent
in another manner permitted hereunder. All notices shall be effective upon
delivery to the address of the addressee. The parties hereto may change their
addresses by giving notice thereof to the other in conformity with this
provision.

            25.7 Separability. If any clause or provision of this Lease is
                 ------------
illegal, invalid, or unenforceable under present or future laws, then the
remainder of this Lease shall not be affected thereby and in lieu of such clause
or provision, there shall be added as a part of this Lease a clause or provision
as similar in terms to such illegal, invalid, or unenforceable clause or
provision as may be possible and be legal, valid, and enforceable.

            25.8 Amendments; and Binding Effect. This Lease may not be amended
                 ------------------------------
except by instrument in writing signed by Landlord and Tenant. No provision of
this Lease shall be deemed to have been waived by Landlord unless such waiver is
in writing signed by Landlord, and no custom or practice which may evolve
between the parties in the administration of the terms hereof shall waive or
diminish the right of Landlord to insist upon the performance by Tenant in
strict accordance with the terms hereof. The terms and conditions contained in
this Lease shall inure to the benefit of and be binding upon the parties hereto,
and upon their respective successors in interest and legal representatives,
except as otherwise herein expressly provided. This Lease is for the sole
benefit of Landlord and Tenant, and other than the Landlord's Mortgagee, no
third party shall be deemed a third party beneficiary hereof.

            25.9 Quiet Enjoyment. Provided Tenant has performed all of its
                 ---------------
obligations hereunder, Tenant shall peaceably and quietly hold and enjoy the
Premises for the Term, without hindrance from Landlord or any party claiming by,
through, or under Landlord, but not otherwise, subject to the terms and
conditions of this Lease.

            25.10 No Merger. There shall be no merger of the leasehold estate
                  ---------
hereby created with the fee estate in the Premises or any part hereof if the
same person acquires or holds, directly or indirectly, this Lease or any
interest in this Lease and the fee estate in the leasehold Premises or any
interest in such fee estate.

            25.11 No Offer. The submission of this Lease to Tenant shall not be
                  --------
construed as an offer, and Tenant shall not have any rights under this Lease
unless Landlord executes a copy of this Lease and delivers it to Tenant.

                                      -22-
<PAGE>

            25.12 Entire Agreement. This Lease constitutes the entire agreement
                  ----------------
between Landlord and Tenant regarding the subject matter hereof and supersedes
all oral statements and prior writings relating thereto. Except for those set
forth in this Lease, no representations, warranties, or agreements have been
made by Landlord or Tenant to the other with respect to this Lease or the
obligations of Landlord or Tenant in connection therewith. The normal rule of
construction that any ambiguities be resolved against the drafting party shall
not apply to the interpretation of this Lease or any exhibits or amendments
hereto.

            25.13 Waiver of Jury Trial. To the maximum extent permitted by law,
                  --------------------
Landlord and Tenant each waive right to trial by jury in any litigation arising
out or with respect to this Lease.

            25.14 Governing Law. This Lease shall be governed by and construed
                  -------------
in accordance with the laws of the State in which the Premises are located.

            25.15 Joint and Several Liability. If Tenant is comprised of more
                  ---------------------------
than one party, each such party shall be jointly and severally liable for
Tenant's obligations under this Lease.

            25.16 Financial Reports. Within fifteen (15) days after Landlord's
                  -----------------
request, Tenant will furnish Tenant's most recent audited financial statements
(including any notes to them) to Landlord, or, if no such audited statements
have been prepared, such other financial statements (and notes to them) as may
have been prepared by an independent certified public accountant or, failing
those, Tenant's internally prepared financial statements. If Tenant is a
publicly traded corporation, Tenant may satisfy its obligations hereunder by
providing to Landlord Tenant's most recent annual and quarterly reports.
Landlord will not disclose any aspect of Tenant's financial statements that
Tenant designates to Landlord as confidential except (1) to Landlord's Mortgagee
or prospective purchasers of the Building, (2) in litigation between Landlord
and Tenant, or (3) if required by court order. Tenant shall not be required to
deliver the financial statements required under this Section 25.16 more than
once in any twelve (12) month period unless (i) requested by Landlord's
Mortgagee or a prospective buyer or lender of the Building, or (ii) an Event of
Default occurs.

            25.17 Landlord's Fees. Whenever Tenant requests Landlord to take any
                  ---------------
action not required of it hereunder, or give any consent required or permitted
under this Lease, Tenant will reimburse Landlord for Landlord's reasonable,
out-of-pocket costs payable to third parties and incurred in reviewing the
proposed action or consent, including without limitation reasonable attorneys',
engineers' or architects' fees, within thirty (30) days after Landlord's
delivery to Tenant of a statement of such costs. Tenant will be obligated to
make such reimbursement without regard to whether Landlord consents to any such
proposed action.

            25.18 Attorney Fees. In the event that either Landlord or Tenant
                  -------------
should bring suit for the possession of the Premises, for the recovery of any
sum due under this Lease, or because of the breach of any provision of this
Lease or for any other relief against

                                      -23-
<PAGE>

the other, then all costs and expenses, including reasonable attorney fees,
incurred by the prevailing party therein shall be paid by the other party, which
obligation on the part of the other party shall be deemed to have accrued on the
date of the commencement of such action and shall be enforceable whether or not
the action is prosecuted to judgment.

            25.19 Telecommunications. With the exception of (i) the initial
                  ------------------
Tenant Improvements to be constructed in accordance with Exhibit D attached
                                                         ---------
hereto which shall be approved by Landlord in accordance with Exhibit D, and
                                                              ---------
(ii) the events described in the last sentence of this Section 25.19, Tenant and
its telecommunications companies, including but not limited to local exchange
telecommunications companies and alternative access vendor services companies
shall have no right of access to and within the Building, for the installation
and operation of telecommunications systems including but not limited to voice,
video, data, and any other telecommunications services provided over wire, fiber
optic, microwave, wireless, and any other transmission systems, for part or all
of Tenant's telecommunications within the Building and from the Building to any
other location without Landlord's prior written consent, which consent shall not
be unreasonably withheld or delayed. Notwithstanding the foregoing to the
contrary, Landlord's prior written consent shall not be required if the
installation in question does not involve a piercing, penetration, or boring of
the Building walls, flooring or structure.

            25.20 Confidentiality. Tenant acknowledges that the terms and
                  ---------------
conditions of this Lease are to remain confidential for Landlord's benefit, and
may not be disclosed by Tenant to anyone, by any manner or means, directly or
indirectly, without Landlord's prior written consent. The consent by Landlord to
any disclosures shall not be deemed to be a waiver on the part of Landlord of
any prohibition against any future disclosure.

            25.21 Hazardous Materials. The term "Hazardous Materials" means any
                  -------------------            -------------------
substance, material, or waste which is now or hereafter classified or considered
to be hazardous, toxic, or dangerous under any Law relating to pollution or the
protection or regulation of human health, natural resources or the environment,
or poses or threatens to pose a hazard to the health or safety of persons on the
Premises or in the Building. Tenant shall not use, generate, store, or dispose
of, or permit the use, generation, storage or disposal of Hazardous Materials on
or about the Premises or the Building except in a manner and quantity necessary
for the ordinary performance of Tenant's business, and then in compliance with
all Laws. If Tenant breaches its obligations under this Section 25.21, Landlord
may immediately take any and all action reasonably appropriate to remedy the
same, including taking all appropriate action to clean up or remediate any
contamination resulting from Tenant's use, generation, storage or disposal of
Hazardous Materials. Tenant shall defend, indemnify, and hold harmless Landlord
and its representatives and agents from and against any and all claims, demands,
liabilities, causes of action, suits, judgments, damages and expenses (including
reasonable attorneys' fees and cost of clean up and remediation) arising from
Tenant's failure to comply with the provisions of this Section 25.21. This
indemnity provision shall survive termination or expiration of the Lease.

                                      -24-
<PAGE>

            25.22 Signage. Tenant shall have the right, at Tenant's sole cost
                  -------
and expense, to install signage identifying Tenant on the Building and on the
monument sign for the Project, subject to the requirements of this Section
25.22. Tenant shall not erect or maintain any other temporary or permanent sign
on or about the Premises, or the Building, or visible from the exterior, without
obtaining prior written approval from Landlord, which shall not be unreasonably
withheld or delayed. Any request for approval of a sign shall be made in such
detail as Landlord shall request. All signs, whether erected by Landlord or
Tenant, shall conform to Landlord's building standard signage and to all Laws,
ordinances, rules, regulations, permits, covenants, conditions, restrictions,
and easements pertaining to signs. In the event of a violation of the foregoing
by Tenant, Landlord may remove same without any liability, and may charge the
expense incurred in such removal to Tenant. Tenant shall remove all approved
signs which it has erected upon the termination of the Lease and repair all
damage caused by such removal.

            25.23 Parking. Tenant shall have the right to the non-exclusive use
                  -------
of the approximately 355 parking spaces in the parking garage/area associated
with the Building (the "Parking Area") during the initial Term free of charge
                        ------------
during the initial Term and subject to such terms, conditions and regulations as
are from time to time applicable to patrons of the Parking Area.

            25.24 List of Exhibits. All exhibits and attachments attached hereto
                  ----------------
are incorporated herein by this reference.

          Exhibit A  Outline of Premises
          Exhibit B  Legal Description of Project
          Exhibit C  Building Rules and Regulations
          Exhibit D  Work Letter Agreement
          Exhibit E  First Amendment to Lease
          Exhibit F  Form of Tenant Estoppel Certificate
          Exhibit G  Guaranty

        26. Extension Option.
            ----------------

            26.1 Grant of Option. Provided no Event of Default exists and Tenant
                 ---------------
is occupying the entire Premises at the time of such election, Tenant may renew
this Lease for two (2) additional periods of sixty (60) months each (each, an
"Extension Term"), by delivering written notice of the exercise thereof to
Landlord not earlier than fifteen (15) months nor later than twelve (12) months
before the expiration of the then Term.

            26.2 Basic Rent. The Basic Rent payable for each month during each
                 ----------
Extension Term shall be the prevailing rental rate (the "Prevailing Rental
                                                         -----------------
Rate"), at the commencement of such Extension Term, for renewals of space of
----
equivalent quality, size, utility and location. The length of the Extension Term
and the credit standing of Tenant shall be taken into account and yearly
increases in the rental rate may be included. Within thirty (30) days after
receipt of Tenant's notice to renew for a particular Extension Term, Landlord
shall deliver to Tenant written notice of the Prevailing Rental Rate for the
applicable

                                      -25-
<PAGE>

Extension Term and shall advise Tenant of the required adjustment to
Basic Rent, if any, and the other terms and conditions offered. Tenant shall,
within thirty (30) days after receipt of Landlord's notice, notify Landlord in
writing whether Tenant accepts or rejects Landlord's determination of the
Prevailing Rental Rate. If Tenant timely notifies Landlord that Tenant accepts
Landlord's determination of the Prevailing Rental Rate, then, on or before the
commencement date of the Extension Term, Landlord and Tenant shall execute an
amendment to this Lease extending the Term on the same terms provided in this
Lease, except as follows:

          (a) Basic Rent shall be adjusted to the Prevailing Rental Rate for
such Extension Term;

          (b) After exercising both options granted herein, Tenant shall have no
further renewal option unless expressly granted by Landlord in writing; and

          (c) Landlord shall lease to Tenant the Premises in their then-current
condition, and Landlord shall not provide to Tenant any allowances (e.g., moving
allowance, construction allowance, and the like) or other tenant inducements.

     For a given Extension Term, if Tenant rejects Landlord's determination of
the Prevailing Rental Rate, Landlord and Tenant shall endeavor to agree upon the
Prevailing Rental Rate on or before the date that is ten (10) days after
Landlord's receipt of Tenant's rejection notice.  If Landlord and Tenant are
unable to agree upon the Prevailing Rental Rate within such ten (10) day period,
then the Prevailing Rental Rate shall be determined by arbitration pursuant to
Section 26.3 below.  If Tenant fails to timely notify Landlord in writing that
Tenant accepts or rejects Landlord's determination of the Prevailing Rental
Rate, Tenant shall conclusively be deemed to have accepted Landlord's
determination of the Prevailing Rental Rate as set forth in Landlord's Notice.

            26.3 Arbitration. If Landlord and Tenant shall fail to agree upon
                 -----------
the Prevailing Rental Rate within ten (10) days after the date of Landlord's
receipt of Tenant's rejection notice, then, within ten (10) days thereafter,
Landlord and Tenant each shall give notice to the other setting forth the name
and address of a broker designated by the party giving such notice, which broker
shall be an independent real estate broker or consultant having at least five
(5) years continuous experience in determining the value of office space in the
community where the Building located. If either party shall fail to give notice
of such designation within such ten (10) day period, then the other broker
chosen shall make the determination alone. If two (2) brokers have been
designated, such two (2) brokers may consult with each other and shall, not
later than the thirtieth (30th) day after Landlord's receipt of Tenant's
rejection notice make their determinations of the Prevailing Rental Rate in
writing and give notice thereof to each other and to each of Landlord and
Tenant. Such two (2) brokers shall have ten (10) days after the receipt of
notice of each other's determination to confer with each other and to attempt to
reach agreement as to the determination of the Prevailing Rental Rate. If such
two (2) brokers shall concur as to the determination of the Prevailing Rental
Rate, such determination shall be final and binding upon Landlord and Tenant. If
such two (2) brokers shall fail to concur within such ten (10) day period, then
such

                                      -26-
<PAGE>

two (2) brokers shall, within the next ten (10) days, designate a third
broker meeting the above requirements for brokers. If the two (2) brokers shall
fail to agree upon the designation of such third broker within such ten (10) day
period, then either party may apply to the DRE for the designation of such
broker. The third broker shall conduct such hearings and investigations on an
expedited basis as such broker may deem appropriate and shall, within fifteen
(15) days after its designation, choose one of the determinations (and no other)
of the two (2) brokers originally selected by the parties by simultaneously
delivering to Landlord and Tenant signed and acknowledged original counterparts
of his or her determination. The costs and expenses of the arbitration and of
the third broker shall be shared equally by Landlord and Tenant and each party
shall be responsible for the costs and expenses of its designated broker and its
own witnesses and counsel. The brokers' final decision and award shall be in
writing, shall be binding on Landlord and Tenant and shall be non-appealable,
and counterpart copies thereof shall be delivered to Landlord and Tenant. A
judgment or order based upon such award may be entered in any court of competent
jurisdiction. In rendering their decision and award, the brokers shall have no
power to vary, modify or amend any provision of this Lease.

            26.4 Termination of Option. Tenant's rights under this Section 26
                 ---------------------
shall terminate if (1) this Lease or Tenant's right to possession of the
Premises is terminated, (2) Tenant assigns any of its interest in this Lease or
sublets any portion of the Premises, or (3) Tenant fails to timely exercise its
Option under this Section 26, time being of the essence with respect to Tenant's
exercise thereof.

       27.  Rent Abatement.
            --------------

            27.1 Basic Rent shall be conditionally abated during the first three
(3) months of the Term. Commencing with the fourth (4th) month of the Term,
Tenant shall make Basic Rent payments as otherwise provided in the Lease.
Notwithstanding such abatement of Basic Rent (a) all other sums due under the
Lease, including Additional Rent and Tenant's share of Taxes shall be payable as
provided in the Lease, and (b) any increases in Basic Rent set forth in the
Lease shall occur on the dates scheduled therefor.

            27.2 The abatement of Basic Rent provided for in this Section is
conditioned upon Tenant's full and timely performance of all of its obligations
under the Lease. If at any time during the Term an Event of Default by Tenant
occurs and remains uncured after the expiration of applicable notice and grace
periods, then the abatement of Basic Rent provided for in this Section shall
immediately become void, and Tenant shall promptly pay to Landlord, in addition
to all other amounts due to Landlord under this Lease, the full amount of all
Basic Rent herein abated.

LANDLORD AND TENANT EXPRESSLY DISCLAIM ANY IMPLIED WARRANTY THAT THE PREMISES
ARE SUITABLE FOR TENANT'S INTENDED COMMERCIAL PURPOSE, AND TENANT'S OBLIGATION
TO PAY RENT HEREUNDER IS NOT DEPENDENT UPON THE CONDITION OF THE PREMISES OR THE
PERFORMANCE BY LANDLORD OF ITS OBLIGATIONS HEREUNDER, AND, EXCEPT AS OTHERWISE
EXPRESSLY PROVIDED HEREIN, TENANT SHALL CONTINUE TO

                                     -27-
<PAGE>

PAY THE RENT, WITHOUT ABATEMENT, SETOFF OR DEDUCTION, NOTWITHSTANDING ANY BREACH
BY LANDLORD OF ITS DUTIES OR OBLIGTIONS HEREUNDER, WHETHER EXPRESS OR IMPLIED.

           Dated as of the date first above written.

TENANT:                              CABLETRON SYSTEMS SALES &
                                     SERVICE, INC.,  a Delaware corporation

                                     By:  /s/ Craig R. Benson
                                          -------------------------------
                                     Name:  Craig R. Benson
                                     Title:  President, Chief Executive Officer

LANDLORD:                            WMP II REAL ESTATE LIMITED
                                     PARTNERSHIP, a Delaware limited partnership

                                     By:  /s/ Nancy M. Haag
                                          -------------------------------
                                     Name:  Nancy M. Haag
                                     Title:  Assistant Vice President


                                      -28-
<PAGE>

                                   EXHIBIT A
                                   ---------

                              OUTLINE OF PREMISES
                              -------------------

     This exhibit depicts the floor plan of the building located at 5200 Great
American Parkway, Santa Clara, California 95054, subject to the lease. The floor
plan demonstrates the lay-out of the building, showing the location and
dimensions of offices, corridors, reception areas, bathrooms, kitchens, storage
and other such areas. The aggregate square footage depicted in the floor plan is
129,200.




                                      -1-
<PAGE>

                                    EXHIBIT B
                                    ---------

                          LEGAL DESCRIPTION OF PROJECT
                          ----------------------------


All that certain Real Property in the City of Santa Clara, County of Santa
Clara, State of California, described as follows:

All of Parcel 1, as shown upon that certain map entitled, "Parcel Map" being all
of Parcels 127 and 128, as shown on that certain "Parcel Map" recorded in Book
430 of Maps, at Page 22, Santa Clara County Records, which map was filed for
record in the Office of the Recorder of the County of Santa Clara, State of
California on November 14, 1980 in Book 475 of Maps, at Page 19.

                                      -1-
<PAGE>

                                   EXHIBIT C
                                   ---------

                         BUILDING RULES AND REGULATIONS
                         ------------------------------


     The following rules and regulations shall apply to the Premises, the
Building and the appurtenances thereto:

     1. Sidewalks, doorways, vestibules, halls, stairways, and other similar
areas shall not be obstructed by Tenants or used by Tenant for purposes other
than ingress and egress to and from the Building and for going from one to
another part of the Building.

     2. Plumbing, fixtures and appliances shall be used only for the purposes
for which designed, and no sweepings, rubbish, rags or other unsuitable material
shall be thrown or deposited therein. Damage resulting to any such fixtures or
appliances from misuse by a tenant or its agents, employees or invitees, shall
be paid by such tenant.

     3. Except as expressly provided in the Lease, no signs, advertisements or
notices shall be painted or affixed on or to any windows or doors or other part
of the Building without the prior written consent of Landlord. Except as
consented to in writing by Landlord or in accordance with Tenant's building
standard improvements, no draperies, curtains, blinds, shades, screens or other
devices shall be hung at or used in connection with any window or exterior door
or doors of the Premises. No awning shall be permitted on any part of the
Premises. Tenant shall not place anything against or near glass partitions or
doors, or windows which might appear unsightly from outside the Premises.

     4. Landlord will furnish Tenant, free of charge, with two keys to the
Building entrance. Landlord may make a reasonable charge for any additional keys
and for having any locks changed. Tenant shall not make or have made additional
keys without Landlord's prior written consent, and Tenant shall not alter any
lock or install a new additional lock or bolt on any door of its Premises
without Landlord's prior written consent. Tenant shall deliver to Landlord upon
termination of its tenancy, the keys to all locks for doors on the Premises, and
in the event of loss of any keys furnished by Landlord, shall pay Landlord
therefor.

     5. If Tenant requires telegraphic, telephonic, burglar alarm or similar
services, it shall first obtain, and comply with, Landlord's reasonable
instructions for their installation.

     6. Tenant shall not use or keep in the Premises any toxic or hazardous
materials, or any kerosene, gasoline or inflammable or combustible fluid or
material other than those limited quantities necessary for the operation or
maintenance of office equipment. Tenant shall not use or permit to be used in
the Premises any foul or noxious gas or substance, or permit or allow the
Premises to be occupied or used in a manner offensive or objectionable to
Landlord or other occupants of the Building by reason of improper, objectionable
or unpleasant noise, odors, or vibrations. No animal except seeing-eye dogs when
in the company of their masters may be brought into or kept in the Building.

                                      -1-
<PAGE>

     7. Landlord will not be responsible for lost or stolen personal property,
money or jewelry from tenant's leased premises or public or common areas
regardless of whether such loss occurs when the area is locked against entry or
not. Tenant assumes any and all responsibility for protecting its Premises from
theft and robbery, which responsibility includes keeping doors locked and other
means of entry to the Premises closed.

     8. Tenant shall not conduct any activity on or about the Premises or
Building which will knowingly draw pickets, demonstrators, or the like.

     9. All vehicles are to be currently licensed, in good operating condition,
parked for business purposes having to do with Tenant's business operated in the
Premises, parked within designated parking spaces, one vehicle to each space.
Tenant shall not leave vehicles in the Building parking areas overnight, or park
any vehicles in the Building parking areas other than automobiles, motorcycles,
motor driven, non-motor driven bicycles, or four wheel drive trucks. No vehicle
shall be parked as a "billboard" vehicle in the parking lot. Any vehicle parked
improperly may be towed away. Tenant, Tenant's agents, employees, vendors and
customers who do not operate or park their vehicles as required shall subject
the vehicle to being towed at the expense of the owner or driver. Landlord may
place a "boot" on the vehicle to immobilize it and may levy a charge of $50.00
to remove the "boot". Tenant shall indemnify, hold and save harmless Landlord of
any liability arising from the towing or booting of any vehicles belonging to a
Tenant Party.

     10. Landlord may waive any one or more of these rules and regulations for
the benefit of Tenant or any other tenant, but no waiver by Landlord shall be
construed as a waiver of the rules and regulations in favor of tenant or any
other Tenant, nor prevent Landlord from thereafter enforcing the rules and
regulations against any or all of the tenants of the Building.

                                      -2-
<PAGE>

                                   EXHIBIT D
                                   ---------

                             WORK LETTER AGREEMENT
                             ---------------------
                         (Tenant Improvement Allowance)


       This Work Letter is attached to and made a part of that certain Lease
Agreement ("Lease") by and between Landlord and Tenant for Premises located at
5200 Great America Parkway, Santa Clara, California, 95054.

1.  Application of Exhibit.  Capitalized terms used and not otherwise defined
    ----------------------
herein shall have the same definitions as set forth in the Lease.  The
provisions of this Work Letter shall apply to the planning and completion of
leasehold improvements to be constructed by Tenant (the "Tenant Improvements")
for the build-out, refurbishment and remodeling of the Premises, as more fully
set forth herein.

2.  Landlord and Tenant Pre-Construction Obligations.
    ------------------------------------------------

       (a) Preliminary Plans. Within ten (10) days following full execution of
           -----------------
the Lease by both Landlord and Tenant, Tenant shall cause V.C. Wong & Associates
("Tenant's Architect") to prepare preliminary space plans for the Tenant
Improvements (the "Preliminary Plans"), which shall include, without limitation,
sketches and/or drawings showing locations of doors, partitioning, electrical
fixtures, outlets and switches, plumbing fixtures, floor loads and other
requirements, and a list of all specialized installations and improvements and
upgrade specifications determined by Tenant as required for its use of the
Premises. The Preliminary Plans shall be reviewed by Landlord's Architect and
the cost thereof shall be included within the Tenant Improvement Allowance.
Landlord and Landlord's Architect shall be entitled, in all respects, to rely
upon all information supplied by Tenant regarding the Tenant Improvements. The
Costs associated with Tenant's Architect's preparation of the Preliminary Plans
shall be borne by Tenant and paid as set forth in Sections 5 and 6 of this Work
Letter.

       (b) Approval of Preliminary Plans. Tenant or Tenant's Architect shall
           -----------------------------
submit the Preliminary Plans to Landlord for Landlord's review and approval,
which approval shall not be unreasonably withheld. Landlord shall notify Tenant
within five (5) business days after delivery thereof if the Preliminary Plans
are approved. If Landlord withholds approval, Landlord shall so notify Tenant
and specify the reasons for withholding such approval. If the Preliminary Plans
are not approved, then within five (5) days after receipt of such notice,
Tenant's Architect shall make all necessary revisions to the Preliminary Plans
and submit two (2) copies thereof to Landlord for its final review and approval,
which approval shall not be unreasonably withheld and shall be given within five
(5) business days thereafter. If no response is given by Landlord within the
five (5) business day period, approval shall be deemed.

                                      -1-
<PAGE>

       (c) Working Drawings. Within fifteen (15) days following the Preliminary
           ----------------
Plans Approval Date, Tenant's Architect shall prepare or cause to be prepared
working drawings (the "Working Drawings") for the Tenant Improvements based upon
the approved Preliminary Plans. The Working Drawings shall include
architectural, necessary mechanical and electrical construction drawings for the
Tenant Improvements based on the Preliminary Plans. Notwithstanding the
Preliminary Plans, in all cases the Working Drawings (i) shall be subject to
Landlord's final approval, which approval shall not be unreasonably withheld or
delayed, (ii) shall not be in conflict with building codes for the City of Santa
Clara ("City") or County of Santa Clara ("County") or with insurance
requirements for a fire resistive building, and (iii) shall be in a form
satisfactory to appropriate governmental authorities responsible for issuing
permits and licenses required for construction. The costs associated with
preparation of the Working Drawings shall be borne by Tenant and paid as set
forth in Sections 5 and 6 of this Work Letter.

       (d) Approval of Working Drawings. Tenant or Tenant's Architect shall
           ----------------------------
submit the Working Drawings to Landlord for its review and approval, which shall
not be unreasonably withheld. Landlord shall notify Tenant within five (5)
business days after delivery thereof if the Working Drawings are approved. If
Landlord withholds approval, Landlord shall so notify Tenant and specify the
reasons for withholding such approval. If the Working Drawings are not approved
within five (5) days after receipt of Landlord's notice, Tenant's Architect
shall make all necessary revisions to the Working Drawings and submit two (2)
copies thereof to Landlord for its final review and approval, which approval
shall not be unreasonably withheld and shall be given within five (5) days
thereafter. If no response is given by Landlord within the five (5) day period,
approval shall be deemed. Concurrently with the above review and approval
process, Tenant may submit all plans and specifications to City and other
applicable governmental agencies in an attempt to expedite City approval and
issuance of all necessary permits and licenses to construct the Tenant
Improvements as shown on the Working Drawings. Any changes which are required by
City or other governmental agencies shall be immediately submitted to Landlord
for Landlord's review and reasonable approval, and to Tenant for Tenant's review
and approval.

       (e) Schedule of Critical Dates. Set forth below is a schedule of certain
           --------------------------
critical dates relating to Landlord's and Tenant's respective obligations for
the design and construction of the Tenant Improvements. Such dates and the
respective obligations of Landlord and Tenant are more fully described elsewhere
in this Work Letter. The purpose of the following schedule is to provide a
reference for Landlord and Tenant and to make certain the Final Approval Date
occurs as set forth herein. Following the Final Approval Date, Tenant shall
commence construction of the Tenant Improvements as set forth in Section 4
below.


    Reference                  Date Due                        Responsible Party
    ---------                  --------                        -----------------

A. "Preliminary Plan         Ten (10) days after full               Tenant
    Completion"              execution of the Lease
B. "Preliminary Plans        Five (5) business days after          Landlord
    Review and Approval"     Tenant submits the
                             Preliminary Plans to Landlord

                                      -2-
<PAGE>

<TABLE>
<CAPTION>
<S>                           <C>                                   <C>

C. "Preliminary Plans           Five (5) days after Landlord           Tenant
    Revision," if necessary     returns the Preliminary Plans
                                to Tenant without approval
D. "Preliminary Plans           Five (5) business days after          Landlord
    Final Approval Date," if    Tenant submits the revised
    necessary                   Preliminary Plans to Landlord
E. "Working Drawings            Fifteen (15) days after the            Tenant
    Completion"                 Preliminary Plans Approval Date
F. "Working Drawings            Five (5) business days after          Landlord
    Review and Approval"        Tenant submits the  Working
                                Drawings to Landlord
G. "Working Drawings            Five (5) days after Landlord           Tenant
    Revision," if necessary     returns the Working Drawings to
                                Tenant without approval
H. "Final Approval Date"        Five (5) business days after          Landlord
                                Tenant submits the revised
                                Working Drawings to Landlord
</TABLE>

3. Building Permit. After the Final Approval Date has occurred, Tenant shall, if
   ---------------
Tenant has not already done so, submit the Working Drawings to the appropriate
governmental body or bodies for final plan checking and a building permit.
Tenant, with Landlord's cooperation, shall cause to be made any changes in the
Working Drawings necessary to obtain the building permit; provided, however,
after the Final Approval Date, no changes shall be made to the Working Drawings
without the prior written approval of both Landlord and Tenant, and then only
after agreement by Tenant to pay any excess costs resulting from such changes.

4.  Construction of Tenant Improvements by Tenant's Agents.
    ------------------------------------------------------

       (a) Construction. After the Final Approval Date has occurred and a
           ------------
building permit for the work has been issued, Tenant shall select a licensed
general contractor ("Contractor"), who shall be reasonably approved by Landlord,
and Tenant shall notify Landlord of same upon its selection. Tenant shall enter
into a construction contract on an AIA form ("Construction Contract") with the
Contractor, who shall cause the construction of Tenant Improvements to be
carried out in substantial conformance with the Working Drawings in a good and
workmanlike manner using first-class materials. The Contractor and Tenant's
Agents (defined in Section 5(c) below) shall abide by all rules and regulations
implemented by Landlord with respect to the construction of the Tenant
Improvements, including carrying appropriate insurance, disruption of other
tenants in the Project, etc. The costs associated with the construction of the
Tenant Improvements shall be borne by Tenant and paid as set forth in Section 5
and 6 of this Work Letter. Tenant shall see that the construction complies with
all applicable building, fire, health, and sanitary codes and regulations, the
satisfaction of which shall be evidenced by a certificate of occupancy for the
Premises.

       (b) Cost Budget. Prior to the commencement of the construction of the
           -----------
Tenant Improvements, and after Tenant has accepted all bids for the Tenant
Improvements, Tenant shall provide Landlord with a detailed breakdown, by trade,
of the final costs to be incurred or which have been incurred in connection with
the design and construction of the Tenant

                                      -3-
<PAGE>

Improvements to be performed by or at the direction of Tenant or the Contractor,
which costs form a basis for the amount of the Contract (the "Final Tenant
Improvement Costs"). Prior to the commencement of construction of the Tenant
Improvements, Tenant shall supply Landlord with an irrevocable letter of credit
as hereinafter described (the "Letter of Credit") in an amount (the "Over
Allowance Amount") equal to the difference between the amount of the Final
Tenant Improvement Costs and the amount of the Tenant Improvement Allowance
(less any portion thereof already disbursed by Landlord, or in the process of
being disbursed by Landlord, on or before the commencement of construction of
the Tenant Improvements), which Letter of Credit shall be held by Landlord until
the Notice of Completion is recorded with respect to the Tenant Improvements,
and returned to Tenant thereafter if not drawn down by Landlord pursuant to this
Exhibit D. --------- Tenant shall be responsible for the payment of the Over
Allowance Amount and shall pay such Amount in coordination with the monthly
disbursement schedule outlined in Section 5(b), by paying to Landlord twenty
(20) days prior to each disbursement by Landlord the amount(s) Landlord needs to
pay each such monthly and final disbursement pursuant to Section 5(b). The Over
Allowance Amount shall be disbursed by Landlord after the disbursement of any of
the then remaining portion of the Tenant Improvement Allowance, and such
disbursement shall be pursuant to the same procedure as the Tenant Improvement
Allowance. In the event that, after the Final Tenant Improvement Costs have been
delivered by Tenant to Landlord, the costs relating to the design and
construction of the Tenant Improvements shall change, any additional costs
necessary to such design and construction in excess of the Final Tenant
Improvement Costs shall be paid by Tenant to Landlord immediately as an addition
to the Over Allowance Amount or, at Landlord's option, Tenant shall make
payments for such additional costs out of its own funds, but Tenant shall
continue to provide Landlord with the documents described in Sections
5(b)(i)(A), (B) (C) and (D) of this Work Letter, above, for Landlord's approval,
prior to Tenant paying such costs. The Letter of Credit described above shall
(i) be an irrevocable standby letter of credit, (ii) be issued by a reputable
bank reasonably approved by Landlord, (iii) name Landlord as beneficiary, (iv)
be payable on sight draft accompanied only by Landlord's statement that Landlord
is entitled to payment thereon because Tenant has failed to make a payment
required of Tenant pursuant to this Exhibit D, (v) be for a term of at least the
                                    ---------
period of time required to complete the Tenant Improvements, and (vi)
assure payment in the total amount of the Over Allowance Amount.

       (c) Notice of Completion. Within ten (10) business days after the
           --------------------
issuance of the permanent or temporary certificate of occupancy for the Tenant
Improvements, Tenant shall cause a Notice of Completion to be recorded in the
office of the Recorder of the County of Santa Clara in accordance with Section
3093 of the Civil Code of the State of California or any successor statute, and
shall furnish a copy thereof to Landlord upon such recordation. If Tenant fails
to do so, Landlord may execute and file the same on behalf of Tenant as Tenant's
agent for such purpose, at Tenant's sole cost and expense. At the conclusion of
construction, (i) Tenant shall cause the Tenant's Architect and Contractor (A)
to update the final Working Drawings as necessary to reflect all changes made to
the Working Drawings during the course of construction, (B) to certify to the
best of their knowledge that the "record set" of mylar as-built drawings are
true and correct, which certification shall survive the expiration or
termination of this Lease, and (C) to deliver to Landlord two (2) sets of copies
of such record set of drawings within ninety (90) days following issuance of a

                                      -4-
<PAGE>

certificate of occupancy for the Premises, and (ii) Tenant shall deliver to
Landlord a copy of all warranties, guaranties, and operating manuals and
information relating to the improvements, equipment and systems in the Premises.

5. Tenant Improvement Allowance.
   ----------------------------

       (a) Tenant Improvement Allowance. Landlord shall provide Tenant with an
           ----------------------------
allowance in an amount not to exceed $10.00 per rentable square foot of the
Premises, or $1,292,000.00 ("Tenant Improvement Allowance") towards the cost of
the design, purchase and construction of the Tenant Improvements, including
without limitation design, engineering and consulting fees (collectively, the
"Tenant Improvement Costs"). The Tenant Improvement Allowance shall be used for
payment of the following Tenant Improvement Costs:

          (i) Preparation by Tenant's space planner and Architect of all
     necessary documents in connection with the Tenant Improvements, including
     without limitation the Preliminary Plans and the Working Drawings as
     provided in Section 2 of this Work Letter, and all fees charged by City
     (including without limitation fees for building permits and plan checks) in
     connection with construction of the Tenant Improvements in the Premises;

          (ii) Construction work for completion of the Tenant Improvements as
     reflected in the Construction Contract including, without limitation,
     testing and inspection costs, freight elevator charges, utility usage, and
     trash removal costs;

          (iii)  All contractors' charges, general conditions, performance bond
     premiums and construction fees;

          (iv) The cost of any changes in the Base Building when such changes
     are required by the Construction Drawings (including all direct
     architectural and/or engineering fees and expenses incurred in connection
     therewith);

          (v) The cost of any changes to the Construction Drawings or Tenant
     Improvements required by applicable Law; and

          (vi) An additional one and one-half percent (1 1/2%) of the amount
     obtained by subtracting the Tenant Improvement Allowance from the total
     Final Tenant Improvement Costs, to be paid to Landlord to defray Landlord's
     supervision costs with respect thereto.

       (b) Disbursement of Tenant Improvement Allowance. During the construction
           --------------------------------------------
of the Tenant Improvements, Landlord shall make monthly disbursements of the
Tenant Improvement Allowance for Tenant Improvement Costs for the benefit of
Tenant and shall authorize the release of monies for the benefit of Tenant as
follows:

                                      -5-
<PAGE>

          (i) Monthly Disbursements.  On or before the tenth (10th) day of each
              ---------------------
     calendar month, as determined by Landlord, during the construction of the
     Tenant Improvements, Tenant shall deliver to Landlord as appropriate:  (A)
     a request for payment of the "Contractor," as that term is defined in
     Section 4 of this Work Letter, approved by Tenant, in a form reasonably
     approved by Landlord, showing the schedule, by trade, of percentage of
     completion of the Tenant Improvements in the Premises, detailing the
     portion of the work completed and the portion not completed; (B) invoices
     from all of "Tenant's Agents" (as defined in Section 5(c) below), for labor
     rendered and materials delivered to the Premises for the applicable payment
     period; (C) executed conditional mechanic's lien releases from all of
     Tenant's Agents which shall comply with the appropriate provisions, as
     reasonably determined by Landlord, of California Civil Code Section
     3262(d); and (D) all other information reasonably requested by Landlord.
     Tenant's request for payment shall be deemed Tenant's acceptance and
     approval of the work furnished and/or the materials supplied as set forth
     in Tenant's payment request.  Thereafter, Landlord shall deliver a check to
     Tenant made jointly payable to Contractor and Tenant in payment of the
     lesser of: (E) the amounts so requested by Tenant, as set forth in this
     Section 5(b) above, less a ten percent (10%) retention (the aggregate
     amount of such retentions to be known as the "Final Retention"), and (F)
     the balance of any remaining available portion of the Tenant Improvement
     Allowance (not including the Final Retention), provided that Landlord does
     not reasonably dispute any request for payment based on non-compliance of
     any work with the approved Working Drawings, or due to any substandard
     work, or for any other reason.  Landlord's payment of such amounts shall
     not be deemed Landlord's approval or acceptance of the work furnished or
     materials supplied as set forth in Tenant's payment request.

               (ii) Final Retention. Subject to the provisions of this Work
                    ---------------
     Letter, a check for the Final Retention payable jointly to Tenant and
     Contractor shall be delivered by Landlord to Tenant following the
     completion of construction of the Premises, provided that (A) Tenant
     delivers to Landlord properly executed mechanics lien releases in
     compliance with both California Civil Code Section 3262(d)(2) and either
     Section 3262(d)(3) or Section 3262(d)(4), (B) Landlord has reasonably
     determined that no substandard work exists which adversely affects the
     mechanical, electrical, plumbing, heating, ventilating and air
     conditioning, life-safety or other systems of the Building, the curtain
     wall of the Building, or the structure or exterior appearance of the
     Building, and (C) Tenant's Architect delivers to Landlord a certificate, in
     a form reasonably acceptable to Landlord, certifying that the construction
     of the Tenant Improvements in the Premises has been substantially
     completed.

          (c) Tenant's Agents. All subcontractors, laborers, materialmen and
              ---------------
     suppliers used by Tenant (such subcontractors, laborers, materialmen and
     suppliers and the Contractor to be known collectively as "Tenant's Agents")
     must be approved in writing by Landlord, which approval shall not be
     unreasonably withheld or delayed.

                                      -6-
<PAGE>

6. Costs in Excess of Tenant Improvement Allowance at Tenant's Expense. Tenant
   -------------------------------------------------------------------
shall pay the excess of the Final Tenant Improvement Costs over the amount of
the Tenant Improvement Allowance available to defray such costs. In the event
the Final Tenant Improvement Costs are less than the Tenant Improvement
Allowance, the difference shall be retained by Landlord.

7.  Change Orders.  Tenant may from time to time request and obtain change
    -------------
orders during the course of construction provided that: (i) each such request
shall be reasonable, shall be in writing and signed by or on behalf of Tenant,
and shall not result in any structural change in the Building, as reasonably
determined by Landlord, (ii) all additional charges and costs, including without
limitation architectural and engineering costs, construction and material costs,
and processing costs of any governmental entity shall be the sole and exclusive
obligation of Tenant, and (iii) any resulting delay in the completion of the
Tenant Improvements shall be deemed a Tenant Delay (as defined below) and in no
event shall extend the Commencement Date of the Lease with respect to the
Premises.  Any additional costs associated with such change orders shall be paid
by Tenant to Landlord immediately.

8.  Tenant Delays.  In no event shall the Commencement Date of the Lease with
    -------------
respect to the Premises be extended or delayed due to or attributable to delays
due to the fault of Tenant ("Tenant Delay(s)") or otherwise.  Tenant Delays
shall include, but are not limited to, delays caused by or resulting from any
one or more of the following:

     (a) Tenant's failure to timely revise, if necessary, the Preliminary Plans
or the Working Drawings;

     (b) Tenant's request for or use of special materials, finishes or
installations which are not readily available;

     (c) Change orders requested by Tenant;

     (d) Interference by Tenant or by Tenant's employees, contractors and/or
agents with the construction activities;

     (e) Tenant's failure to approve any other item or perform any other
obligation in accordance with and by the dates specified herein or in the
Construction Contract;

     (f) Tenant's requested changes in the Preliminary Plans, Working Drawings
or any other plans and specifications after the approval thereof by Tenant or
submission thereof by Tenant to Landlord;

     (g) Tenant's failure to approve written estimates of costs in accordance
with this Work Letter; and

     (h) Tenant's obtaining or failure to obtain any necessary governmental
approvals or permits for Tenant's intended use of the Premises.

                                      -7-
<PAGE>

9.  Trade Fixtures And Equipment.  Tenant acknowledges and agrees that Tenant is
    ----------------------------
solely responsible for obtaining, delivering and installing in the Premises all
necessary and desired furniture, trade fixtures, equipment and other similar
items, and that Landlord shall have no responsibility whatsoever with regard
thereto.  Tenant further acknowledges and agrees that neither the Commencement
Date of the Lease nor the payment of Rent shall be delayed for any period of
time whatsoever due to any delay in the furnishing of the Premises with such
items.

10. Failure of Tenant to Comply.  Any failure of Tenant to comply with any of
    ---------------------------
the provisions contained in this Work Letter within the times for compliance
herein set forth shall be deemed a default under the Lease.  In addition to the
remedies provided to Landlord in this Work Letter upon the occurrence of such a
default by Tenant, Landlord shall have all remedies available at law or equity
against a defaulting tenant pursuant to a written contract, including but not
limited to those set forth in the Lease.

11. Inspection by Landlord.  Landlord shall have the right to inspect the
    ----------------------
Tenant Improvements at all times; provided, however, that Landlord's failure to
inspect the Tenant Improvements shall in no event constitute a waiver of any of
Landlord's rights hereunder, nor shall Landlord's inspection of the Tenant
Improvements constitute Landlord's approval of the same. Should Landlord
reasonably disapprove any portion of the Tenant Improvements, Landlord shall
notify Tenant in writing of such disapproval and shall specify the items
disapproved. Any defects or deviations in, and/or disapproval by Landlord of,
the Tenant Improvements shall be rectified, if necessary, by Tenant at no
expense to Landlord; provided, however, that in the event Landlord determines
that a defect or deviation exists or disapproves of any matter in connection
with any portion of the Tenant Improvements and such defect, deviation or matter
might adversely affect the mechanical, electrical, plumbing, heating,
ventilating and air-conditioning or life-safety systems of the Building, the
structure or exterior appearance of the Building or any other tenant's use of
such other tenant's leased premises, Landlord may take such action as Landlord
reasonably deems necessary, at Tenant's expense and without incurring any
liability on Landlord's part, to correct any such defect, deviation and/or
matter, including, without limitation, causing the cessation of performance of
the construction of the Tenant Improvements until such time as the defect,
deviation and/or matter is corrected to Landlord's reasonable satisfaction.

12. Conferences.  Commencing upon the execution of this Lease, Tenant shall
    -----------
confer frequently with the Architect and the Contractor, either in person or by
telephone as appropriate, regarding the progress of the preparation of Working
Drawings and the construction of the Tenant Improvements.  Minutes shall be
taken at all such conferences, a copy of which minutes shall be promptly
delivered to Landlord.  One such conference each month shall include the review
of Contractor's current request for payment.

13. Miscellaneous.
    -------------

     (a) Tenant's Representative.  Tenant has designated Don MacNeil as its sole
         -----------------------
representative with respect to the matters set forth in this Work Letter, who,
until further

                                      -8-
<PAGE>

notice to Landlord, shall have full authority and responsibility to act on
behalf of the Tenant as required in this Work Letter.

     (b) Landlord's Representative.  Landlord has designated Insignia Commercial
         -------------------------
Group, Inc., as its sole representative with respect to the matters set forth in
this Work Letter, who, until further notice to Tenant, shall have full authority
and responsibility to act on behalf of the Landlord as required in this Work
Letter.

     (c) Time of the Essence.  Unless otherwise indicated, all references herein
         -------------------
to a "number of days" shall mean and refer to calendar days.  In all instances
where Tenant is required to approve or deliver an item, if no written notice of
approval is given or the item is not delivered within the stated time period,
then Tenant shall be deemed to have approved the same.

14.  Landlord Work.  Within ninety (90) days after the Commencement Date,
     -------------
Landlord shall, at its sole cost and expense, commence to thin the landscaping
along Great America Parkway and construct the improvements set forth on the
proposed bid attached hereto as Exhibit D-1. Landlord shall diligently prosecute
such construction to completion.

                                      -9-
<PAGE>

                                   EXHIBIT E

                            FIRST AMENDMENT TO LEASE
                      ACKNOWLEDGMENT OF COMMENCEMENT DATE

     This FIRST AMENDMENT TO LEASE (this "Amendment") is executed as of
__________, 2000 between WMP II Real Estate Limited Partnership, a Delaware
limited partnership ("Landlord"), and Cabletron Systems Sales & Service, Inc., a
                      --------
Delaware corporation ("Tenant"), for the purpose of amending the Lease Agreement
                       ------
between Landlord and Tenant dated January 6, 1999 (the "Lease").  Capitalized
terms used herein but not defined shall be given the meanings assigned to them
in the Lease.

                                   AGREEMENTS

     For valuable consideration, whose receipt and sufficiency are acknowledged,
Landlord and Tenant agree as follows:

     1. Condition of Premises. Tenant has accepted possession of the Premises
        ---------------------
pursuant to the Lease. Any improvements required by the
terms of the Lease to be made by Landlord have been completed to the full and
complete satisfaction of Tenant in all respects except for the punch list items
described on Exhibit A hereto (the "Punch List Items"), and except for such
Punch List Items, Landlord has fulfilled all of its duties under the Lease with
respect to such initial tenant improvements. Furthermore, Tenant acknowledges
that the Premises are suitable for the Permitted Use.

     2. Commencement Date. The Commencement Date of the Lease is March 1, 1999.
        -----------------
If the Commencement Date set forth in the Lease is different than the date set
forth in the preceding sentence, then the Commencement Date as contained in the
Lease is amended to be the Commencement Date set forth in the preceding
sentence.

     3. Expiration Date. The Term is scheduled to expire on February 28, 2006.
        ---------------
If the scheduled expiration date of the initial term as set forth in the Lease
is different than the date set forth in the preceding sentence, then the
scheduled expiration date as set forth in the Lease is hereby amended to the
expiration date set forth in the preceding sentence.

     4. Contact Numbers. Tenant's telephone number in the Premises is
        ---------------
Tenant's __________ telecopy number in the Premises is ____________.

     5. Ratification. Tenant hereby ratifies and confirms its obligations under
        ------------
the Lease, and represents and warrants to Landlord that it has no defenses
thereto. Additionally, Tenant further confirms and ratifies that, as of the date
hereof, the Lease is and remains in good standing and in full force and effect,
and Tenant has no claims, counterclaims, set-offs or defenses against Landlord
arising out of the Lease or in any way relating thereto or arising out of any
other transaction between Landlord and Tenant.

                                      -1-
<PAGE>

     6. Binding Effect; Governing Law. Except as modified hereby, the Lease
        -----------------------------
shall remain in full effect and this Amendment shall be binding upon Landlord
and Tenant and their respective successors and assigns. If any inconsistency
exists or arises between the terms of this Amendment and the terms of the Lease,
the terms of this Amendment shall prevail. This Amendment shall be governed by
the laws of the State in which the Premises is located.

     7. Counterparts. This Amendment may be executed in multiple counterparts,
        ------------
each of which shall constitute an original, but all of which shall constitute
one document.

     Executed as of the date first written above.

     TENANT:             CABLETRON SYSTEMS SALES & SERVICE
                         INC., a Delaware corporation

                         By:  _________________________________

                         Name:  _________________________________

                         Title:  _________________________________


     LANDLORD:           WMP II REAL ESTATE LIMITED
                         PARTNERSHIP,  a Delaware limited partnership

                         By:   WMP II GEN-PAR, INC., a Delaware corporation,
                               General Partner

                         By:  _________________________________
                         Name:  Nancy M. Haag
                         Title: Assistant Vice President

                                      -2-
<PAGE>

                          EXHIBIT A TO AMENDMENT NO. I

                                PUNCH LIST ITEMS (1)
                                ----------------









































(1) No "Punch List Items" have been omitted from this exhibit.

                                      -1-

<PAGE>

                                EXHIBIT F

                      FORM OF TENANT ESTOPPEL CERTIFICATE
                      -----------------------------------

     The undersigned is the Tenant under the Lease (defined below) between WMP
II Real Estate Limited Partnership, a Delaware limited partnership, as Landlord,
and the undersigned as Tenant, for the Premises located in the office building
at 5200 Great America Parkway, Santa Clara, California, 95054, and commonly
known as a portion of Great America Plaza, and hereby certifies as follows:

     1. The Lease consists of the original Lease Agreement dated as of January
6, 1999 between Tenant and Landlord and the following amendments or
modifications thereto (if none, please state
"none"):_____________________________________________________

___________________________________________________________________________
___________________________________________________________________________
___________________________________________________________________________

The documents listed above are herein collectively referred to as the "Lease"
                                                                       -----
and represent the entire agreement between the parties with respect to the
Premises.  All capitalized terms used herein but not defined shall be given the
meaning assigned to them in the Lease.

     2. The Lease is in full force and effect and has not been modified,
supplemented or amended in any way except as provided in Section I above.

     3. The Term commenced on ____________, 199__ and the Term expires,
excluding any renewal options, on ____________, 200__ and Tenant has no option
to purchase all or any part of the Premises or the Building or, except as
expressly set forth in the Lease, any option to terminate or cancel the Lease.

     4. Tenant currently occupies the Premises described in the Lease and Tenant
has not transferred, assigned, or Sublet any portion of the Premises nor entered
into any license or concession agreements with respect thereto except as follows
(if none, please state "none"):

___________________________________________________________________________
___________________________________________________________________________
___________________________________________________________________________
___________________________________________________________________________

     5. All monthly installments of Basic Rent and Additional Rent have been
paid when due through ____________. The current monthly installment of Basic
Rent is $__________.

     6. All conditions of the Lease to be performed by Landlord necessary to the
enforceability of the Lease have been satisfied and Landlord is not in default
thereunder. In addition, Tenant has not delivered any notice to Landlord
regarding a default by Landlord thereunder.

                                      -1-
<PAGE>

     7. As of the date hereof, there are no existing defenses or offsets, or, to
the undersigned's knowledge, claims or any basis for a claim, that the
undersigned has against Landlord and no event has occurred and no condition
exists, which, with the giving of notice or the passage of time, or both, will
constitute a default under the Lease.

     8. No rental has been paid more than thirty (30) days in advance and no
security deposit has been delivered to Landlord except as provided in the Lease.

     9. If Tenant is a corporation, partnership or other business entity, each
individual executing this Estoppel Certificate on behalf of Tenant hereby
represents and warrants that Tenant is a duly formed and existing entity
qualified to do business in the state in which the Premises is located and that
Tenant has full right and authority to execute and deliver this Estoppel
Certificate and that each person signing on behalf of Tenant is authorized to do
so.

     10. There are no actions pending against Tenant under any bankruptcy or
similar laws of the United States or any state.

     11. Other than in compliance with all applicable laws and incidental to the
ordinary course of the use of the Premises, the undersigned has not used or
stored any hazardous substances in the Premises.

     12. All tenant improvement work to be performed by Landlord under the Lease
has been completed in accordance with the Lease and has been accepted by the
undersigned and all reimbursements and allowances due to the undersigned under
the Lease in connection with any tenant improvement work have been paid in full.

     13. Tenant acknowledges that this Estoppel Certificate may be delivered to
Landlord, Landlord's Mortgagee or to a prospective mortgagee or prospective
purchaser, and their respective successors and assigns, and acknowledges that
Landlord, Landlord's Mortgagee and/or such prospective mortgagee or prospective
purchaser will be relying upon the statements contained herein in disbursing
loan advances or making a new loan or acquiring the property of which the
Premises are a part and that receipt by it of this certificate is a condition of
disbursing loan advances or making such loan or acquiring such property.

     Executed as of _________,  2000.

     TENANT:             CABLETRON SYSTEMS SALES & SERVICE,
                         INC., a Delaware corporation

                         By:  _________________________________
                         Name:  _________________________________
                         Title:  _________________________________

                                      -2-
<PAGE>

                                    GUARANTY
                                    --------

     As a material inducement to Landlord to enter into the Lease, dated January
6, 1999 (the "Lease"), between Cabletron Systems Sales & Service, Inc., a
              -----
Delaware corporation, as Tenant, and WMP II Real Estate Limited Partnership, a
Delaware limited partnership, as Landlord, Cabletron Systems, Inc., a Delaware
corporation ("Guarantor") hereby unconditionally and irrevocably guarantees for
              ---------
the benefit of Landlord the complete and timely performance of each obligation
of Tenant (and any assignee) under the Lease and any extensions or renewals of
and amendments to the Lease.  This Guaranty is an absolute, primary, and
continuing, guaranty of payment and performance and is independent of Tenant's
obligations under the Lease. Guarantor (and if this Guaranty is signed by more
than one person or entity, each Guarantor hereunder) shall be primarily liable,
jointly and severally, with Tenant and any other guarantor of Tenant's
obligations.  Guarantor waives any right to require Landlord to (a) join Tenant
with Guarantor in any suit arising under this Guaranty, (b) proceed against or
exhaust any security given to secure Tenant's obligations under the Lease, or
(c) pursue or exhaust any other remedy in Landlord's power.  Landlord may,
without notice or demand and without affecting Guarantor's liability hereunder,
from time to time, compromise, extend or otherwise modify any or all of the
terms of the Lease.  Until all of Tenant's obligations to Landlord have been
discharged in full, Guarantor shall have no right of subrogation against Tenant.
Guarantor waives any right to participate in any security now or later held by
Landlord.  Guarantor waives all presentments, demands for performance, notices
of nonperformance, protests, notices of protest, dishonor, and notices of
acceptance of this Guaranty, and waives all notices of existence, creation, or
incurring of new or additional obligations from Tenant to Landlord.  Without
limiting the generality of the preceding waivers, Guarantor hereby expressly
waives any and all benefits under California Civil Code Sections 2809, 2810,
2819, 2845, 2847, 2848, 2849 and 2850, and the second sentence of California
Civil Code Section 2822(a).  The liability of Guarantor under this Guaranty will
not be affected by (1) the release or discharge of Tenant from, or impairment,
limitation or modification of, Tenant's obligations under the Lease in any
bankruptcy, receivership, or other debtor relief proceeding, whether state or
federal and whether voluntary or involuntary; (2) the rejection or disaffirmance
of the Lease in any such proceeding; or (3) the cessation from any cause
whatsoever of the liability of Tenant under the Lease.  Guarantor shall pay to
Landlord all costs incurred by Landlord in enforcing this Guaranty (including,
without limitation, reasonable attorneys' fees and expenses). The obligations of
Tenant under the Lease to execute and deliver estoppel statements, as therein
provided, shall be deemed to also require the Guarantor hereunder to do so and
provide the same relative to Guarantor following written request by Landlord in
accordance with the terms of the Lease.

     IN WITNESS WHEREOF, Guarantor has executed this Guaranty as of this 9th day
of February, 1999.

GUARANTOR:                    CABLETRON SYSTEMS, INC.
                              a Delaware corporation
                              Tax I.D. Number:  04-2797263

                                      -1-
<PAGE>

                              By:  /s/ Craig R. Benson
                                   --------------------------------
                              Name:  Craig R. Benson
                              Title:  President, Chief Executive Officer

                                     -2-
<PAGE>

                        TENANT'S ESTOPPEL CERTIFICATE


PROJECT:          Great America Parkway

LEASED PREMISES:  5200 Great America Parkway

LANDLORD:         WMP II Real Estate Limited Partnership

TENANT:           Cabletron Systems Sales & Services, Inc.

LEASE DATED:      January 6, 1999 ("Lease")
                                    -----


     The undersigned tenant ("Tenant"), in recognition that Sagamore Equities
                              ------
LLC ("Buyer") is considering an acquisition of the Project, and that General
      -----
Electric Capital Corporation (together with its successors and assigns,
"Lender") is considering providing financing for such acquisition, hereby
 ------
certifies to Buyer and Lender that:

     1.  Tenant has accepted possession of the Premises pursuant to the Lease.
A true and accurate copy of the Lease is attached hereto.  The Lease term
commenced on March 1, 1999.  The termination date of the Lease term, excluding
any unexercised renewals and extensions, is February 28, 2006.  Tenant has not
assigned its rights under the Lease or sublet any portion of the leased
premises.  The Lease is dated January 6, 1999 and has not been amended except as
follows: [List the dates of any amendments or modifications of the Lease] NONE.
          --------------------------------------------------------------

     2.  Any improvements required by the terms of the Lease to be made by
Landlord have been completed to the satisfaction of Tenant in all respects, and
Landlord has fulfilled all of its duties under the Lease.

     3.  Except as disclosed in Paragraph 1 above, the Lease has not been
assigned, modified, supplemented or amended in any way.  The Lease constitutes
the entire agreement between the parties and there are no other agreements or
understandings between Landlord and Tenant concerning the Premises.  The
undersigned does not have any option or preferential right to purchase all or
any part of the Premises or the building of which the Premises are a part or any
right, title or interest with respect to the Premises or such building other
than as Lessee under the Lease and Tenant does not have any right or option to
renew or extend the term of the Lease, or to lease other space within the
building of which the Premises are a part, except as follow: Tenant has two (2)
sixty-month options to renew.

     4.  The Lease is valid and in full force and effect, and to the best of
Tenant's knowledge, neither Landlord nor Tenant is in default thereunder.
Tenant has no defense, setoff or counterclaim against Landlord arising out of
the Lease or against the payment of rent or other charges under the Lease or in
any way relating thereto, or arising out of any
<PAGE>


other transaction between Tenant and Landlord, and no event has occurred and
no condition exists, which with the giving of notice or the passage of time,
or both, will constitute a default under the Lease. Tenant is current in the
payment of any taxes, utilities, common area maintenance or other charges to
be paid by Tenant.

     5.  There are no actions, whether voluntary or involuntary, pending against
Tenant under any insolvency, bankruptcy or other debtor relief laws of the
United States of America or of the State of California.

     6.  The minimum monthly rent presently payable under the Lease is $213,180.
Landlord is holding a security deposit of $0.  Landlord holds no other funds for
Tenant's account.  No rent or other sum payable under the Lease has been paid
more than one month in advance.  Pursuant to the Lease, Tenant is obligated to
reimburse Landlord for its percentage share of all real property taxes,
operating expenses, common area maintenance and insurance expenses affecting the
project of which the Premises are a part, which percentage share is equal to
100% for the Leased Premises and 56.70% for the Property.


                         Cabletron Systems Sales & Service, Inc.

                         By: /s/ David Kirkpatrick
                             ----------------------------

                             David Kirkpatrick, EVP and CFO
                             ------------------------------
                                [Printed Name and Title]

                         Date:         June 13      , 2000
                               ---------------------



                          GUARANTOR'S ACKNOWLEDGEMENT
                          ---------------------------

The undersigned (a) has guaranteed the obligations of the Tenant under the Lease
referred to above, (b) consents to the matters set forth above and agrees to be
bound thereby, and acknowledges that the guaranty executed by the undersigned is
in full force and effect and will not be supplemented, modified, amended or
terminated without the prior written consent of the Lender.


                         Cabletron Systems, Inc.


                         By: /s/ David Kirkpatrick
                             ----------------------------

                             David Kirkpatrick, EVP and CFO
                             ------------------------------
                                [Printed Name and Title]