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                        CONFIDENTIAL TREATMENT REQUESTED


                           DARK FIBER LEASE AGREEMENT

         THIS DARK FIBER LEASE AGREEMENT (the "AGREEMENT") is made and entered
into as of this 21st day of November, 2001 (the "EFFECTIVE DATE"), by and
between QWEST COMMUNICATIONS CORPORATION, a Delaware corporation ("QWEST"), and
COGENT COMMUNICATIONS, INC., a Delaware corporation ("LESSEE").


                                    RECITALS:

         A. Qwest through ownership or other arrangement possesses the right to
use and operate a fiber optic telecommunications network between various points
in the United States (the "QWEST SYSTEM" or "QWEST NETWORK").

         B. Lessee desires to be granted a lease in certain optical fibers in
particular segments of the Qwest System (the "SEGMENT"), which Segments will
consist of both Lessee Fibers in Rings or Building Laterals (defined below) and
are more particularly described on EXHIBIT A, and Qwest desires to grant Lessee
a lease in such Lessee Fibers in the Segments, upon the terms and conditions set
forth in this Agreement.

         NOW THEREFORE, in consideration of the mutual promises set forth below,
and other good and valuable consideration, the receipt and sufficiency of which
are hereby acknowledged, the parties hereby agree as follows:

I.       DEFINITIONS

The following capitalized terms shall have the following meanings when used in
this Agreement, unless explicitly stated to the contrary:

         "ACCEPTANCE" or "ACCEPTED" means the Delivery by Qwest and acceptance
by Lessee of a Ring or Building Lateral, as set forth in Section 5.

         "ACCEPTANCE DATE" means the date on which a Ring or Building Lateral is
Accepted pursuant to Section 5.

         "ACCEPTANCE PERIOD" is defined in Section 5.5.

         "AFFILIATE" means any person, which directly or indirectly controls or
is controlled by, or is under common control with a party to this Agreement.

         "ALLOCABLE SHARES" means, for purposes of apportioning responsibility
for costs, the ratio of the number of Lessee Fibers in a relevant Segment to the
total number of Fibers in the same Segment. For example, if Lessee's interest in
the relevant Segment is


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two (2) strands of fiber and there are a total of one hundred (100) strands of
fiber in the relevant Segment, Lessee's Allocable Share is two (2) of one
hundred (100) or two percent (2%).

         "ASSOCIATED PROPERTY" means tangible and intangible property needed for
the use of Lessee's Fibers in a Segment, including but not limited to: (i) the
associated conduit; (ii) Qwest's interests in the Underlying Rights; and (iii)
access to Connecting Points. Associated Property excludes electronic or optronic
equipment.

         "BUILDING LATERAL" means a Segment of Fiber from a building to a Ring
on the Qwest Network.

         "BUILDING LATERAL FEE" is defined in Section 4.2.

         "CONNECTING POINTS" means the mutually agreed upon splice points in
Qwest manholes, handholes, or fiber distribution panels which can be used to
access Lessee's Fibers in the Qwest Network.

         "COSTS" means all actual, direct costs paid or payable in accordance
with the established accounting procedures generally used by Qwest and which it
utilizes in billing third parties for reimbursable projects which costs shall
include the following: (i) internal labor, including wages and salaries, and
benefits, and overhead allocable to such labor costs, and (ii) other direct
costs and out-of-pocket expenses on a pass-through basis (e.g., equipment,
materials, supplies, contract services, etc.).

         "CROSS-CONNECT PANEL" means the piece of equipment designated by Qwest
in a Qwest POP at which Lessee's Fibers are terminated and at which location
Lessee may have access to and interconnect with Lessee's Fibers through use of
Local Distribution Facilities or other facilities acceptable to Qwest.

         "DELIVER" or "DELIVERY" of a Ring or Building Lateral means that the
applicable Lessee Fibers are available for use at the applicable Qwest
demarcation point.

         "DELIVERY DATE" is the date that Qwest Delivers the Lessee Fibers to
Lessee.

         "DISCLOSING PARTY" is defined in Section 17.1 herein.

         "EFFECTIVE DATE" is defined in the first paragraph of this Agreement.

         "EXPECTED DELIVERY DATE" is the date that Qwest expects to Deliver the
Lessee Fibers to Lessee pursuant to an Order.

         "FIBER(S)" means the Qwest strands of optical fiber in the Qwest
System.

         "IMPOSITIONS" means all taxes, fees, levies, imposts, duties, charges,
contributions or withholdings of any nature (including, without limitation,
gross receipts taxes and franchise, license and permit fees), together with any
penalties, fines, or interest thereon arising out of the transactions
contemplated by this Agreement and/or imposed upon


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either party hereto by any federal, state or local government or other public
taxing authority of any country.

         "INSOLVENT" means the occurrence of any of the following events,
whereby either party (i) becomes or is declared insolvent or bankrupt; (ii) is
the subject of any judicial proceedings related to its liquidation, insolvency
or for the appointment of a receiver or similar officer for it; (iii) makes an
assignment for the benefit of all or substantially all of its creditors; or (iv)
enters into an agreement for the composition, extension, or readjustment of all
or substantially all of its obligations.

         "LEASE FEE" is defined in Section 4.1.

         "LESSEE FIBER(S)" means the Fiber in a Segment leased by Qwest to
Lessee for the Lessee Fiber Term, in accordance with this Agreement.

         "LESSEE FIBER TERM" shall mean either a Lessee Ring Fiber Term or a
Lessee Building Lateral Fiber Term.

         "LESSEE RING FIBER TERM" is defined in Section 3.2.

         "LESSEE BUILDING LATERAL FIBER TERM" is defined in Section 3.3.

         "LOCAL DISTRIBUTION FACILITIES" means those telecommunications
transmission facilities that interconnect with the applicable Lessee Fibers at a
Cross-Connect Panel and extend each Segment of the applicable Lessee Fiber to a
location outside of the Qwest POP.

         "ORDER" means an order mutually agreed to between the Parties as set
forth in Section 5 pursuant to which Lessee will lease a Ring or Building
Lateral and/or Qwest will perform construction or splicing work.

         "ORDER DATE" means the date on which Qwest receives an Order under the
procedures established pursuant to Section 5.

         "PLANNED SYSTEM WORK PERIOD" or "PSWP" means a prearranged period of
time reserved for performing certain work on the Qwest Network that may
potentially impact traffic. Generally, this will be restricted to weekends,
avoiding the first and last weekend of each month and high-traffic weekends. The
PSWP shall be agreed upon pursuant to EXHIBIT B.

         "POP" means the Qwest terminal facility (point of presence) where the
Lessee Fibers are delivered to Lessee.

         "PROPRIETARY INFORMATION" is defined in Section 17.1 herein.

         "QWEST NETWORK" or "QWEST SYSTEM" means the fiber optic
telecommunications network operated by Qwest in the United States, including at
the election of Qwest such telecommunications capacity as Qwest may obtain from
another network provider and



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integrate into its own network for purposes of providing services or leased
fibers to Qwest's lessees. Although Qwest possesses telecommunications network
facilities and capacity in locations other than the United States, such network
facilities and capacity are not part of the Qwest Network for purposes of this
Agreement.

         "RECIPIENT PARTY" is defined in Section 17.1 herein.

         "REGULATIONS" are defined in Section 20.1 herein.

         "RENEWAL RESPONSE" is defined in Section 3.4 herein.

         "RENEWAL TERM" is defined in Section 3.4 herein.

         "REQUEST" shall mean a written request by Lessee to Qwest to lease a
Ring or Building Lateral or for Qwest to perform either construction or splicing
work for Lessee.

         "RING" means a continuous loop of local network backbone Fiber in the
Qwest Network.

         "ROUTE MILES" means the length of a Ring, as reasonably determined by
Qwest.

         "SEGMENT" means particular Rings and/or Building Laterals of the Qwest
System leased by Lessee.

         "TERM" is defined in Section 3.1 herein.

         "UNDERLYING RIGHTS" means certain rights of way, licenses,
authorizations, easements, leases, fee interests, franchises and other
agreements necessary for construction and operation of the Qwest Network in
accordance with this Agreement. Underlying Rights shall expressly include, but
not be limited to, Qwest's lease rights in a building location, any applicable
rules to a building, and Qwest's private right of way from the manhole to the
building point of entry at each location.

         "UNDERLYING RIGHTS REQUIREMENTS" means the requirements, restrictions,
and/or limitations on the Fibers listed by Lessee, and safety, operational and
other rules and regulations imposed in connection with the Underlying Rights.

2.       LEASE

         2.1 Subject to the terms and conditions set forth in this Agreement and
upon Qwest's acceptance of an Order, Qwest hereby leases to Lessee, and Lessee
hereby agrees to lease from Qwest the Rings and Building Laterals set forth in
the applicable Order. Qwest further grants, and Lessee accepts, subject to the
terms and conditions in this Agreement, the nonexclusive right of use of any
necessary Associated Property.


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3.       TERM OF AGREEMENT; TERM, RENEWAL AND TERMINATION OF LESSEE FIBER.

         3.1 The term of this Agreement for lease (the "TERM") shall begin on
the Effective Date and shall terminate upon the expiration of the final Lessee
Fiber Term for Lessee Fibers leased under this Agreement.

         3.2 The term of any given Lessee Fibers in a Ring shall begin on the
Acceptance Date for such Ring and shall terminate of the last day of the [*]
calendar month following such Acceptance Date (each a "LESSEE RING FIBER TERM").

         3.3 The term of any given Lessee Fibers in a Building Lateral shall
begin on the Acceptance Date for such Building Lateral and shall terminate of
the last day of the [*] calendar month following such Acceptance Date (each a
"LESSEE BUILDING LATERAL FIBER TERM").

         3.4 Lessee may notify Qwest of Lessee's desire to renew Lessee's lease
to any Ring leased hereunder upon no less than [*] months notice before the
expiration of the existing Lessee Ring Fiber Term. Within [*] days of Qwest's
receipt of such notification, Qwest shall notify Lessee whether Qwest, in its
reasonable discretion, has approved such request for renewal and, if applicable,
the new term (the "RENEWAL TERM") and the applicable Lease Fee for such renewal
("RENEWAL RESPONSE"). If Qwest does not respond to Lessee within [*] days of
Qwest's receipt of Lessee's notification, then the request shall be deemed
rejected. Lessee shall notify Qwest within [*] days of Lessee's receipt of the
Renewal Response whether Lessee desires to renew the applicable Ring subject to
the terms in the Renewal Response. Pricing for Rings during a Renewal Term shall
be [*]. The Renewal Response shall take precedence over any additional or
different terms incorporated in Lessee's response to which notice of objection
is hereby given. If Lessee accepts the Renewal Response, then the Lessee Ring
Fiber Term and Lessee Fiber for such Ring shall be amended to incorporate the
terms of such Renewal Response.

         3.5 Lessee shall be granted [*] month renewals to the initial Lessee
Building Lateral Fiber Term for each Building Lateral ([*] a "RENEWAL TERM")
upon receipt by Qwest of written notice from Lessee requesting [*] renewals.
Lessee shall provide Qwest with written notice of Lessee's desire to renew
Lessee's lease to any Building Lateral leased hereunder no less than [*] months
before the expiration of the existing initial Lessee Fiber Term or the Renewal
Term, if applicable. At the expiration of the [*] Renewal Term, Lessee may
notify Qwest of Lessee's desire to renew Lessee's lease to the Building Lateral
for an additional [*] month term upon no less than [*] months notice before the
expiration of the existing Renewal Term. Within [*] days of Qwest's receipt of
such notification, Qwest shall notify Lessee whether Lessee will be granted the
additional Renewal Term. [*] Lessee shall not have any rights to perform
maintenance of the Building Lateral unless mutually agreed between the Parties.

         3.6 At the expiration or termination of any applicable Product Order,
the lease of the applicable Lessee Fibers shall immediately terminate unless
renewed pursuant to


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the process set forth in Section 3.4 or 3.5. above, and all rights of Lessee to
use the applicable Associated Property, or any part thereof, shall cease.

         3.7 Lessee may terminate its lease of a Ring after the Acceptance Date
by providing Qwest prior written notice. The termination of the applicable lease
shall be effective upon Lessee's Acceptance of Ring(s) with an equal or greater
Lease Fee than the terminated Ring. Lessee shall be obligated to pay the
terminated Lease Fee until the Acceptance by Lessee of the replacement Ring(s).
Lessee can terminate a lease to a Building Lateral by providing Qwest with
written notice. The termination of Lessee's lease to the applicable Building
Lateral shall be effective sixty (60) days from the date that Qwest received
Lessee written notice of termination. Qwest shall not have any obligation to
refund any of the applicable Building Lateral Fee to Lessee.

4.       CONSIDERATION FOR LESSEE FIBERS

         4.1 In consideration of the lease of each Ring hereunder, Lessee shall
pay to Qwest the stated monthly fee as set forth in EXHIBIT E (Pricing) for such
Ring (the "LEASE FEE") for the term of Lessee Ring Fiber Term for such Ring. The
Lease Fee shall be exclusive of maintenance costs for the Rings. Lessee shall
commence making such payments with respect to each Ring upon the first business
day of the first calendar month commencing [*]. The first Lease Fee payment
shall include payment from the Acceptance Date to the last day of the month
during which the Acceptance Date occurs, as well as payment for the first full
month after the Acceptance Date. The Lease Fee for any partial month shall be
prorated based on the number of days in that month. For the term of each Ring,
Lessee shall also pay to Qwest an annual operation and maintenance charge,
payable monthly, calculated at the rate of [*], which will begin to be applied
to each Ring leased herein on the Acceptance Date thereof, and shall continue
for the Lessee Ring Fiber Term associated with the Ring. The operations and
maintenance fee shall also be prorated based on the number of days in any
partial month.

         4.2 In consideration of the lease of each Building Lateral hereunder,
Lessee shall pay to Qwest [*] (the "BUILDING LATERAL FEE"). For those Building
Laterals not already identified on EXHIBIT A or added to EXHIBIT A subsequent to
the execution of this Agreement, the parties shall determine whether a Building
Lateral [*] in their commercially reasonable judgment. The Building Lateral Fee
shall be exclusive of all maintenance costs for the Building Lateral. Payment of
such Building Lateral Fee will allow Lessee to use of [*] Lessee Fibers in such
Building Lateral. Lessee shall remit payment of [*] of the Building Lateral Fee
to Qwest concurrent with placing the Order for such Building Lateral. Lessee
shall pay Qwest the balance of the Building Lateral Fee no later than
[*]calendar days after Lessee Accepts the Building Lateral for the term of each
Building Lateral. Lessee shall also pay to Qwest an annual operation and
maintenance charge, payable yearly, calculated at the rate of [*] to a connected
Building Lateral, which will begin to be applied to each Building Lateral leased
herein on the Acceptance Date. Lessee shall pay the annual operation and
maintenance charge concurrent with the [*] balance payment upon Acceptance of
the Building Lateral and on each anniversary of the Acceptance Date throughout
the Lessee Building Lateral Fiber Term.


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         4.3 If Lessee fails to make any payment under this Agreement within
five (5) business days of when due, such amount shall accrue interest from the
date such payment is due until paid at a rate of [*] per annum or the maximum
rate provided by law, whichever is less.

         4.4 The Parties agree that in order to receive the pricing set forth in
EXHIBIT E, Lessee must place Orders for [*] Fiber Miles of Ring [*] months of
the Effective Date, and place Orders for [*] Fiber Miles [*] months of the
Effective Date. Qwest shall use commercially reasonable efforts to notify Lessee
if Lessee has not placed Orders for enough Rings in sufficient time to meet the
required minimums. Qwest's failure to notify Lessee shall not be deemed a breach
of this Agreement and shall not effect Lessee's obligation to pay the minimum
Lease Fee as set forth herein. If Lessee fails to place Orders for the minimum
Fiber Mile requirement, then Qwest shall invoice Lessee for the deficiency in
the Fiber Mile requirement at a rate of [*] per month times the number of Fiber
Miles for which Lessee should have placed Orders to meet its minimum
requirements. As Lessee Accepts additional Fiber Miles, Qwest shall reduce the
[*] per month per Fiber Mile charge on a mile for mile basis until Lessee has
met its Fiber Mile minimum requirement. (By way of example, if Lessee has a
deficiency of 50 Fiber Miles and later Accepts an additional 25 Fiber Miles,
Qwest shall reduce the deficiency charge by 25 Fiber Miles)

5.       ORDERS, DELIVERY AND ACCEPTANCE TESTING

         5.1 The initial Rings and Building Laterals available for lease by
Lessee, subject to Qwest's acceptance of such request, shall be set forth on
EXHIBIT A, which may be amended from time to time by Qwest to add (but not to
subtract) Rings or Building Laterals. The list of Rings and Building Laterals
that Lessee has leased from Qwest are set forth in EXHIBITS A1 and A2,
respectively, which exhibits may be amended from time to time to reflect the
actual Rings and Building Laterals so leased. The Parties acknowledge and agree
that any Building Laterals ordered pursuant to this Agreement must connect to a
Qwest Ring. Lessee will, from time to time, request to lease a Segment pursuant
to the terms and conditions herein by providing Qwest with one or more written
Request. Each such Request shall indicate Lessee's proposed Segments, the number
of fibers, and the Qwest metropolitan market(s). Qwest shall respond to Lessee
in writing within fifteen (15) business days of receiving such Request by either
accepting or rejecting such Request in its commercially reasonable judgment. Any
acceptance of a Request by Qwest shall include any specific conditions that may
effect or impact Lessee's use of the Ordered Segment in a material way and the
Expected Delivery Date. If Qwest does not respond to a Request within fifteen
(15) business days, then the Request shall be deemed rejected. Lessee shall
respond to Qwest's response within fifteen (15) business days of receiving such
response. Lessee shall have the option of continuing with the Request subject to
the additional terms stated by Qwest or canceling the Request. [*] The Parties
shall have the right but not the obligation to negotiate the terms of any
Request. Once the Parties have mutually agreed upon the terms of a Request, then
Lessee shall submit a written Order in a form reasonably requested by Qwest. The
Order Date shall be the date on which Qwest receives the written Order.


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         5.2 Qwest shall use commercially reasonable efforts to Deliver any
Segment to Lessee by the estimated Delivery Date mutually agreed to by the
Parties in the Order ("EXPECTED DELIVERY DATE"). If a Ring is not Delivered to
Lessee within [*] days after the Expected Delivery Date, then Lessee may either
terminate the Order for the applicable Ring or the Parties may negotiate a
revised Expected Delivery Date. If a Ring is not Delivered to Lessee within [*]
days after the Expected Delivery Date, then either Party may terminate the
Product Order with no further obligations under the applicable Product Order. If
either Party terminates an Order for a Ring pursuant to this Section, [*]. If a
Building Lateral is not Delivered to Lessee within [*] days after the Expected
Delivery Date, then Qwest shall pro rate the monthly Lease Fee for the Ring on
which the applicable Building Lateral will connect equal to [*] of the Lease Fee
for each day that Qwest is late in delivering the Building Lateral past the
Expected Delivery Date plus [*] days. If a Building Lateral is not Delivered to
Lessee within [*] days after the Expected Delivery Date, then Lessee may either
revise the Expected Delivery Date subject to Qwest's approval or terminate the
Order. In the event that Lessee terminates the Order for a Building Lateral
pursuant to this Section, [*]. The pro rating of the monthly Lease Fee shall
cease upon Qwest's Delivery of the Building Lateral to Lessee.

         5.3 Upon Delivery, the Lessee Fibers shall comply with the technical
specifications set forth in EXHIBIT B hereto. Qwest shall test each Segment in
accordance with the procedures specified in EXHIBIT B to verify that it is
operating in accordance with the technical specifications in EXHIBIT B. Qwest
shall provide Lessee with reasonable advance notice of the date and time of each
applicable acceptance test so that Lessee shall have the right, but not the
obligation, to have a person or persons present to observe the tests. Upon
Lessee's request, Qwest shall promptly provide Lessee with a copy of the test
results.

         5.4 In the event the results of any applicable acceptance test show
that the Lessee Fibers are not operating in accordance with the applicable
technical specifications in EXHIBIT B, Qwest shall promptly take action that is
commercially reasonable to bring the Segment of the Lessee Fibers that is not
operating within the applicable technical specifications into compliance with
such standards. In no event shall the unavailability, incompatibility, delay in
installation, or other impairment of any of Lessee's interconnection facilities
including Lessee's suppliers (E.G., a local access telephone service provider)
be used as a basis for rejecting any portion of the Fibers granted hereunder.

         5.5 Qwest will notify Lessee in writing when any applicable Segment of
the Lessee Fibers has met the technical specifications in EXHIBIT B. Within
twenty (20) days of receipt of such notice ("ACCEPTANCE PERIOD"), Lessee shall
sign and deliver an Acceptance letter to Qwest acknowledging the Delivery of
each Segment of Lessee Fibers in the System Route. By signing the Acceptance
letter, Lessee acknowledges that each Segment of Lessee Fiber listed in the
Acceptance letter complies with the applicable technical specifications. The
date of such signing shall become the Acceptance Date. If Lessee determines that
any Segment of Lessee Fiber does not comply with the technical specifications,
it shall notify Qwest in writing within the Acceptance Period. Such notice shall
specify in detail how the applicable Segment of Lessee Fiber does not conform.
If


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Lessee fails to provide such notice within the Acceptance Period, or if the
notice does not provide reasonable specificity, Lessee is deemed to have
Accepted the applicable leased Fiber Segments on the expiration of the
Acceptance Period, which shall then become the Acceptance Date. [*].

         5.6 If Lessee requests Fibers in a Building Lateral identified on
EXHIBIT A, and such requested Fibers are not available due to unavailability of
Fibers in such Building Lateral, Lessee may submit a Request that Qwest pull an
additional fiber bundle through the existing conduit, or to use another of
Qwest's building conduits, if available ("WORK REQUEST"). The Parties will
follow the Request and Order process set forth above in Section 5.1. If Qwest
accepts the Work Request, then the Parties shall negotiate in good faith the
terms and conditions for such work and any credits for Lessee for the sale or
lease of Fibers from the fiber bundle so installed that are not taken by Lessee.
Qwest shall not be under any obligation to perform such construction work for
Lessee unless set forth in a written Order.

         5.7 Lessee shall at all times be entitled to install fiber optic cable
to any buildings not set forth on EXHIBIT A at its own cost and expense,
provided that Lessee shall comply with applicable standards and parameters set
forth in this Agreement. Lessee may submit a Request that Qwest provide
Connecting Points to such laterals in accordance with EXHIBIT C hereto. The
Parties will follow the Request and Order process set forth above in Section
5.1. If Qwest accepts an Order under this Section, then Qwest shall use
commercially reasonable efforts to provide access to Connecting Points subject
to the terms and conditions set forth in EXHIBIT C hereto. Qwest shall not be
under any obligation to provide Connecting Points unless set forth in a written
Order.

6.       OPERATIONS AND MAINTENANCE

         6.1 The lease of the Lessee Fibers does not provide Lessee with the
right to physically access, encumber or to use the Qwest Network except as
expressly set forth herein. The Lessee Fibers are subject to and provisioned in
accordance with the technical specifications in Sections 1-3 of EXHIBIT B
hereto, which may be modified from time to time subject to the standards and
practices of the industry. Qwest shall provide Lessee with annual notice of any
changes to the technical specifications set forth in EXHIBIT B, but in no event
shall Qwest's failure to provide such notice be deemed an Event of Default.

         6.2 Qwest will use commercially reasonable efforts to operate and
maintain the Lessee Fibers in accordance with the operations and maintenance
specifications and procedures in Section 4 of EXHIBIT B hereto. However, the
operations and maintenance requirements herein do not ensure that the Lessee
Fibers will perform in accordance with the technical specifications in EXHIBIT B
following the Effective Date.

         6.3 This Agreement does not obligate Qwest to supply to Lessee any
optical or electrical equipment, or other facilities, including without
limitation, generators, batteries, air conditioners, fire protection equipment,
monitoring equipment and testing


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equipment, all of which are the sole responsibility of Lessee. Qwest is not
responsible for performing any work other than as specifically set forth in this
Agreement.

7.       PERMITS; UNDERLYING RIGHTS; RELOCATION

         7.1 Qwest has obtained, or will obtain prior to the relevant Effective
Date, the Underlying Rights, at Qwest's sole cost and expense, for the
construction, operation and maintenance of the Lessee Fibers. The lease of the
Fibers is subject and subordinate to the terms of the Underlying Rights,
including, but not limited to, covenants, conditions, restrictions, easements,
reversionary interests, bonds, mortgages and indentures, and other matters,
whether or not of record, and to the rights of tenants and licensees in
possession. The lease of the Fibers is further subject and subordinate to the
prior right of the grantor of the Underlying Rights to use the right of way for
other business activities, including railroad operations, telecommunications
uses, pipeline operations or any other purposes, and to the prior right of Qwest
to use its rights granted under the Underlying Rights. The rights granted herein
are expressly made subject and subordinate to each and every limitation,
restriction or reservation affecting the Underlying Rights. Nothing herein shall
be construed as to be a representation, warranty or covenant of Qwest's right,
title or interest with respect to the right of way or the Underlying Rights.

         7.2 Upon the expiration or other termination of an Underlying Right
that is necessary in order to grant, continue or maintain the Lessee Fibers
hereunder, Qwest shall be responsible either to renew such Underlying Right or
to obtain an alternate right of way at no cost to Lessee. In the event Qwest
loses an Underlying Right during a Lessee Fiber Term or needs such Underlying
Right in order to grant a Renewal Term to Lessee, and Qwest requests assistance
by Lessee in obtaining such Underlying Right, Lessee agrees to use commercially
reasonable efforts to assist Qwest in obtaining such Underlying Right (I.E.,
assisting Qwest in gaining access to a building for which Lessee has obtained
access rights). If at any time during the Term a federal, state or local
government authority or agency seeks to impose any new, material Underlying
Right on the Lessee Fibers above and beyond current charges, Lessee shall be
responsible for paying its Allocable Share of such new charges to Qwest.

         7.3 If Qwest is required to relocate any part of the Qwest Network
during a Lessee Fiber Term, including any of the facilities used or required in
providing the Lessee Fibers, Qwest shall reasonably determine the extent of, the
timing of, and methods to be used for such relocation; provided that any such
relocation shall be constructed and tested in accordance with the specifications
set forth in EXHIBIT B, and incorporate Fiber meeting the specifications of the
original leased Lessee Fiber. Qwest shall bear the costs of such relocation.

         7.4 Qwest shall deliver to Lessee updated as built drawings with
respect to the relocated Segment within ninety (90) days following the
completion of such relocation.

         7.5 In the event of a relocation, Qwest may, at its sole discretion,
route the Lessee Fibers through additional terminal, end link, POP or
regeneration facilities that are not required under this Section 7, in which
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additional Costs and expenses associated with those additional, non-required
facilities only.

         7.6 Relocation pursuant to this Section shall not effect the applicable
Lessee Fiber Term.

8.       ACCESS TO QWEST POPS

         8.1 Lessee and its designees (such as local telecommunications
providers) shall have access to each Qwest POP specified in EXHIBIT A (if any
are specified) for the purposes of interconnecting with each granted Segment of
Lessee Fiber. Such access and interconnection shall be subject to the access and
interconnection standards and procedures regularly established by Qwest, as
modified by it from time to time.

9.       USE OF QWEST NETWORK

         9.1 Lessee represents and warrants that the use of the Lessee Fibers by
its customers or end users shall comply with all applicable laws, ordinances,
rules, regulations and restrictions, and will be used for interstate purposes
only.

         9.2 This Agreement grants no right to Lessee to use any element of the
Qwest Network other than the right to use the Lessee Fibers and Associated
Property pursuant to the terms hereof. Qwest shall not cause or permit any of
Lessee's rights under this Agreement or any Lessee equipment connected to any
leased Segment to become subject to any mechanic's, materialmen's, or vendor's
lien, or any similar lien. Lessee shall keep any and all of the Qwest Network,
including the Lessee Fibers, free from any liens, rights or claims of any third
party attributable to Lessee or its use of the Qwest Network.

         9.3 Lessee shall be responsible for the configuration and operation of
Lessee's network using the Lessee Fibers, including the provisioning of all
Local Distribution Facilities, interconnection facilities, network equipment,
testing equipment and procedures, maintenance (other than maintenance of the
Lessee Fibers or any portion of the Qwest Network), and other facilities or
actions necessary to use the Lessee Fibers. Local Distribution Facilities shall
be separately acquired by Lessee and may be provided by a local telephone
company or other third party, and must comply with Qwest's applicable
engineering and operations requirements. Local Distribution Facilities are not
part of the Lessee Fibers, and Lessee's Acceptance of each Segment hereunder may
not be conditioned upon the availability of such Local Distribution Facilities.
Lessee shall conduct all operations and use of the Lessee Fibers in a manner
that does not interfere with the Qwest Network or the use thereof by Qwest or
any other customer of Qwest. Lessee shall comply at all times with Qwest's
operating procedures and interconnection requirements.

         9.4 Lessee shall hold Qwest harmless to Lessee's customers and limit
the liability of Lessee for interruptions, failures, or degradation of service
to the charges received by Lessee for such service.


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         9.5 Lessee and Qwest agree to cooperate and support each other in
complying with any requirements applicable to their respective rights and
obligations in this Agreement imposed by any governmental agency, regulatory
agency or authority.

10.      INDEMNIFICATION

         10.1     [*]:

                        (a)      [*];

                        (b)      [*];

                        (c)      [*]; and

                        (d)      [*].

         10.2     [*]:

                  (a)      [*];

                  (b)      [*]; or

                  (c)      [*].

         10.3 Nothing contained herein shall operate as a limitation on either
party's right to bring an action for damages against any third party, such
damages to include, but not be limited to, direct, indirect, special,
consequential or punitive damages, based on any acts or omissions of a third
party that may affect Qwest or Lessee, as the case may be.

11.      LIMITATION OF LIABILITY; DISCLAIMER OF WARRANTIES

         11.1 NEITHER PARTY SHALL BE LIABLE TO THE OTHER FOR ANY SPECIAL,
INCIDENTAL, INDIRECT, PUNITIVE, RELIANCE OR CONSEQUENTIAL DAMAGES, WHETHER OR
NOT SUCH DAMAGES WERE FORESEEABLE OR A PARTY WAS NOTIFIED IN ADVANCE OF THE
POSSIBILITY OF SUCH DAMAGES.

         11.2 LESSEE ACKNOWLEDGES THAT, EXCEPT AS SPECIFICALLY SET FORTH IN THIS
AGREEMENT, QWEST MAKES NO WARRANTY REPRESENTATION OR INDEMNITY WITH RESPECT TO
THE LEASED FIBERS, THE QWEST NETWORK, THE ASSOCIATED PROPERTY AND SERVICES, THE
FACILITIES, OR ANY WORK PERFORMED UNDER THIS AGREEMENT, INCLUDING ANY AND ALL
WARRANTIES, IMPLIED OR EXPRESS, OF DESIGN, MERCHANTABILITY, NONINFRINGEMENT OF A
THIRD PARTY'S RIGHTS, OR FITNESS FOR A PARTICULAR PURPOSE OR ARISING FROM A
COURSE OF DEALING, USAGE OR TRADE, AND CUSTOMER HEREBY EXPRESSLY WAIVES AND
DISCLAIMS ALL SUCH WARRANTIES,

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REPRESENTATIONS AND INDEMNITIES. THE WARRANTIES SET FORTH IN THIS AGREEMENT
CONSTITUTE THE ONLY WARRANTIES MADE BY QWEST TO CUSTOMER WITH RESPECT TO THIS
AGREEMENT AND ARE MADE IN LIEU OF ALL OTHER WARRANTIES MADE BY QWEST TO CUSTOMER
WITH RESPECT TO THIS AGREEMENT AND ARE MADE IN LIEU OF ALL OTHER WARRANTIES,
WRITTEN OR ORAL, STATUTORY, EXPRESS OR IMPLIED.

         11.3 IN NO EVENT SHALL EITHER PARTY'S THE CUMULATIVE LIABILITY UNDER
THIS AGREEMENT EXCEED [*] TO THE EXTENT ALLOWED BY LAW.

12.      INSURANCE

         12.1 Lessee shall at all times during the term of this Agreement, at
its own cost and expense, carry and maintain the insurance coverage listed below
with insurers having a minimum "Best's" rating of A VII. Lessee shall require
its subcontractors and agents to maintain the same insurance.

               (a) Commercial General Liability insurance covering claims for
          bodily injury, death, personal injury or property damage (including
          loss of use) occurring or arising out of the license, use or occupancy
          of any premises in connection with this Agreement by Lessee, including
          coverage for premises-operation, products/completed operations and
          contractual liability with respect to the liability assumed by Lessee
          hereunder. The limits of insurance shall not be less than:

               Each Occurrence                       [*]
               a)                                    General Aggregate      [*]

               Products/Completed Operations         [*]
               Personal & Advertising Injury         [*]

               (b) Workers' Compensation insurance with statutory limits as
          required in the state(s) of operation; and providing coverage for any
          employee entering onto any premises in connection with this Agreement,
          even if not required by statute. Employer's Liability or "Stop Gap"
          insurance with limits of not less than [*] each accident.

               (c) Comprehensive Automobile Liability insurance covering the
          ownership, operation and maintenance of all owned, non-owned and hired
          motor vehicles used in connection with this Agreement, with limits of
          at least [*] per occurrence for bodily injury and property damage.

               (d) Any other insurance coverage specifically required of such
          party pursuant to Qwest's right of way agreements with railroads and
          other third parties.

         12.2 The insurance limits required herein may be obtained through any
combination of primary and excess or umbrella liability insurance.
Self-insurance can be


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utilized for a retention of up to [*]. Lessee shall forward to Qwest
certificate(s) of such insurance upon execution of this Agreement and upon any
renewal of such insurance during the Term. The certificate(s) shall provide that
(i) Qwest Communications Corp. (and its participating affiliates) be named as
additional insured as their interest may appear with respects this Agreement;
(ii) at least thirty (30) days prior written notice of cancellation, material
change or exclusion to any required policy shall be given to Qwest; (iii)
coverage is primary and not excess of, or contributory with, any other valid and
collectible insurance purchased or maintained by Qwest.

13.      PAYMENT

         13.1 Other than the monthly payments due pursuant to Section 4 herein,
all other payments due hereunder, if any, shall be due thirty (30) days after
the date of receipt of the invoice by Lessee. If any amount due under this
Agreement is not received by its respective due date, such amount shall accrue
interest as provided in Section 4. All disputes or requests for billing
adjustments must be submitted in writing by the due date and submitted with
payment of all undisputed amounts due. Any amounts which are determined by Qwest
to be in error or not in compliance with Agreement shall be adjusted on the next
month's invoice. Disputes shall not be cause for Lessee to delay payment of the
undisputed balance to Qwest according to the terms outlined in this Section, and
shall be addressed pursuant to Section 21 if not otherwise resolved by the
parties. Invoices submitted to Lessee by Qwest shall conform to Qwest's standard
billing format and content, as modified by Qwest from time to time.

         13.2 Either party may offset any amounts not paid when due from any
amounts that such party owes to the other party under any other agreements
between the parties.

14.      CHARACTERIZATION OF TRANSACTION

         14.1 The parties intend that the lease of the Fibers granted in this
Agreement does not provide Lessee with any ownership or other possessory
interests in any real property, conduit, fiber, or equipment pertaining to the
Associated Property, the Qwest Network, or along the System Route of the Qwest
Network. Further, it is not the intention of the parties to create a loan or
other financing arrangement between the parties.

15.      TAXES, FEES AND OTHER GOVERNMENTAL IMPOSITIONS

         15.1 Qwest is responsible for Impositions with respect to the
construction or operation of the Qwest Network which are (a) imposed or assessed
prior to the Effective Date; or (b) imposed or assessed in exchange for the
approval of the original construction of the Qwest Network.

         15.2 Except as set forth in Section 15.1 herein, each party shall be
responsible for paying any and all Impositions accessed against such party by
any authorized governmental tax authority. The parties agree that they will
cooperate with each other and coordinate their mutual efforts concerning audits,
or other such inquiries, filings,


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reports, etc., as may relate solely to the activities or transactions arising
from or under this Agreement, which originate from an authorized governmental
tax authority.

16.      NOTICE

         16.1 Unless otherwise provided herein, all notices and communications
concerning this Agreement shall be in writing and addressed to the other party
as follows:

         If to Qwest:           Qwest Communications Corporation
                                Attention:  QwestLink PMO Director
                                1670 Broadway, 26th Floor
                                Denver, Colorado 80202
                                Telephone No.:  (303) 992-1400
                                Facsimile No.:  (303) 992-7162

         with a copy to:        Qwest Communications Corporation
                                Attention:  Vice President & General Counsel
                                1801 California, Suite 3800
                                Denver, Colorado  80202
                                Telephone No.:  (303) 992-1400
                                Facsimile No.:  (303) 295-6973

         If to Lessee:          Cogent Communications, Inc.
                                Attention:  CFO
                                1015 31st Street, NW
                                Washington, DC 20007
                                Telephone No.:  (202) 295-4200
                                Facsimile No.:  (202) 338-8798

         with a copy to:        Cogent Communications, Inc.
                                Attention:  Vice President & General Counsel
                                1015 31st Street, NW
                                Washington, DC 20007
                                Telephone No.:  (202) 295-4200
                                Facsimile No.:  (202) 338-8798

or at such other address as either party may designate from time to time in
writing to the other party.

         16.2 Unless otherwise provided herein, notices shall be delivered by
hand, registered or certified U.S. mail (postage prepaid), by commercial
overnight delivery service, or by facsimile. Notices shall be deemed delivered
upon receipt if delivered by hand (if acknowledgment of receipt is obtained),
upon confirmation if delivered by facsimile, one (1) day after delivery if sent
by overnight delivery service, or three (3) days after deposit in the mail when
sent by U.S. mail.

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17.      CONFIDENTIALITY

         17.1 Qwest and Lessee agree that if either party (the "DISCLOSING
PARTY") provides confidential or proprietary, non-public information
("PROPRIETARY INFORMATION") to the other party (the "RECIPIENT PARTY"), such
Proprietary Information shall be held in confidence, and the Recipient Party
shall afford Proprietary Information the same care and protection as it affords
generally to its own confidential and proprietary information (which in any case
shall be not less than reasonable care) in order to avoid disclosure to or
unauthorized use by any third party. This Agreement, including its existence and
all of the terms, conditions and provisions, constitutes Proprietary
Information. All information disclosed by either party to the other in
connection with or pursuant to this Agreement shall also be deemed to be
Proprietary Information, provided that written information is clearly marked in
a conspicuous place as confidential or proprietary, and verbal information is
indicated as being confidential or proprietary when given or promptly confirmed
in writing as such thereafter. All Proprietary Information, unless otherwise
specified in writing, shall remain the property of the Disclosing Party, shall
be used by the Recipient Party only for its intended purpose. All Proprietary
Information, including all copies thereof, shall be returned to the Disclosing
Party or destroyed after the Recipient Party's need for it has expired or upon
the request of the Disclosing Party. Proprietary Information shall not be
reproduced except to the extent necessary to accomplish the purpose and intent
of this Agreement, or as otherwise may be permitted in writing by the Disclosing
Party.

         17.2 The foregoing provisions of Section 17.1 shall not apply to any
Proprietary Information which: (i) becomes publicly available other than through
disclosure by the Recipient Party; (ii) is required to be disclosed by law, rule
or regulation, or by court order; (iii) is independently developed by the
Recipient Party; (iv) becomes available to the Recipient Party without
restriction from a third party; or (v) becomes relevant to the settlement of any
dispute or enforcement of either party's rights under this Agreement in
accordance with its terms and conditions. If any Proprietary Information is
required to be disclosed pursuant to this Section, the party required to make
such disclosure shall immediately inform the other party of the requirements of
such disclosure and take all reasonable protective measures to preserve the
confidentiality of such Proprietary Information as fully as possible in the
context of such permitted disclosure.

         17.3 Notwithstanding Sections 17.1 and 17.2, either party may disclose
Proprietary Information to its employees or agents, its legal, financial, and
accounting advisors, and to its lenders with a need to know such Proprietary
Information, provided that the Disclosing Party notifies any recipient of its
confidential and proprietary nature and obtains, in advance, an agreement in
writing from the recipient to be bound by the non-disclosure obligations of this
Section.

         17.4 The provisions of this Section 17 shall survive for a period of
two (2) years from the date of the expiration or termination of this Agreement.

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18.      DEFAULT

         18.1 A party shall be in default under the Agreement upon the
occurrence of an Event of Default. The defaulting party shall have thirty (30)
days after the non-defaulting party gives written notice of default to the
defaulting party to cure the default (unless the default is cured or waived in
writing by the non-defaulting party within the thirty (30) day period). However,
in such cases where a default cannot be cured within the thirty (30) day period
by the exercise of diligent, commercially reasonable effort, the party in
default must cure the default within ninety (90) days after the non-defaulting
party gives its notice. Notwithstanding the preceding provisions, if the default
is for Lessee's non-payment of any amount due under Section 4 of this Agreement,
the Lessee shall have five (5) days from the date a payment is due to cure the
default, and in cases of such payment default Qwest is not required to send a
written notice of default to Lessee.

         18.2 Events of Default shall mean the following: (i) failure to make
any payment when due; (ii) breach of any material provision not cured within the
applicable cure period; or (iii) either party is or becomes Insolvent.

         18.3 In addition to the specific remedies provided in this Agreement,
upon giving notice of default, the non-defaulting party may: (i) take any action
it determines to be necessary to correct the default; and (ii) pursue any other
legal or equitable remedies it may have under applicable law that are consistent
with the terms of this Agreement.

19.      TERMINATION

         19.1 Qwest may terminate this Agreement upon the failure of Lessee to
cure an Event of Default before the expiration of the applicable cure period, if
any, as required by Section 18. In the event that Qwest terminates this
Agreement due to an uncured Event of Default by Lessee, all monthly Lease Fee
payments for the remainder of the Lessee Fiber Term for such Ring or Building
Lateral shall become immediately due and payable. In the event either party
fails to cure an Event of Default within the applicable cure period, the
aggrieved party may pursue any legal or equitable remedy available to it under
applicable law, subject to the dispute resolution provisions herein.

         19.2 Upon the expiration or termination of this Agreement, all rights
of Lessee to use the Qwest System, the Fibers, the Associated Property or any
part thereof shall cease. Promptly thereupon, Lessee shall remove all of
Lessee's electronics, equipment, and other Lessee property from Qwest facilities
at its sole cost, under Qwest's supervision. Upon termination or expiration of
this Agreement, each party shall return all of the other party's Confidential
Information in its possession or control.

         19.3 The defined terms and the rights and obligations set forth in the
following sections shall survive the termination or expiration of the Agreement:
10 (Indemnification), 11 (Limitation of Liability, Disclaimer of Warranties), 17
(Confidentiality), 21 (Arbitration), 22 (Waiver), 23 (Governing Law), 24 (Rules
of Construction), 26 (Publicity), 28 (No Personal Liability), 30 (No Third
Beneficiaries), 31 (Severability), 33 (Entire Agreement; Amendment).


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20.      FORCE MAJEURE

         20.1 Neither party shall be in default under this Agreement if its
failure to perform is caused by any of the following conditions: act of God;
fire; flood; fiber cut; power outages; material shortages or unavailability or
other delay in delivery not resulting from the responsible party's failure to
timely place orders; lack of or delay in transportation; government codes,
ordinances, laws, rules, regulations, orders approvals or restrictions
(collectively, "REGULATIONS"); war or civil disorder; labor unrest or strike; or
any other cause beyond the commercially reasonable control of the effected
party; provided the condition giving rise to such claim for relief under this
Section was not due to the actions of the party claiming relief under this
Section. The party claiming relief under this Section shall promptly notify the
other in writing of the existence of the event relied upon and the cessation or
termination of that event. For the duration of any valid force majeure event,
the performance of the effected party shall be excused.

21.      ARBITRATION

         21.1 Either party shall notify the other in writing upon the existence
of any dispute pertaining to this Agreement. The parties agree to work in good
faith to resolve the dispute during the thirty (30) day period after the written
notice is delivered. If the parties are unable to reach a settlement of the
dispute within the thirty (30) day period, either party may file a demand for
arbitration in the offices of the American Arbitration Association. The
arbitration shall take place in New York, New York. The arbitration shall be
conducted in accordance with the Commercial Arbitration Rules of the American
Arbitration Association in effect at the time the demand for arbitration is
filed. If the parties are unable to agree on a single arbitrator within thirty
(30) days from the commencement of arbitration, each party shall select an
arbitrator and the two (2) arbitrators shall promptly select a third neutral
arbitrator, the three of whom shall serve as an arbitration panel. The decision
of the arbitrator(s) shall be final and binding upon the parties and shall
include written findings of law and fact. Any award issued by the arbitrator(s)
may be reduced to a judgment and entered in a court of competent jurisdiction.
Each party shall bear its own fees and costs in connection with the arbitration,
except for the fees and expenses of the arbitrator(s), which shall be borne
equally by the parties.

         21.2 The obligation to arbitrate shall not be binding upon any party
with respect to requests for preliminary injunctions, temporary restraining
orders or other similar temporary procedures in a court of competent
jurisdiction to obtain interim relief when deemed necessary by such court to
preserve the status quo or prevent irreparable injury pending resolution by
arbitration of the actual dispute. It is not the intention of the parties that
such injunctive procedures shall be in lieu of, or cause substantial delay to,
any arbitration proceeding commenced under Section 21.1 above.

22.      WAIVER

         22.1 The failure of either party to enforce any provision of this
Agreement, or the waiver of any provision, shall not be construed as a general
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on its part of any such provision, but the same shall nevertheless be and remain
in full force and effect. A waiver of any provision of this Agreement is only
valid if given in writing executed by an authorized representative of the
waiving party.

23.      GOVERNING LAW

         23.1 This Agreement shall be governed by and construed in accordance
with the domestic laws of the State of New York, without reference to choice of
law principles.

24.      RULES OF CONSTRUCTION

         24.1 The captions or headings in this Agreement are strictly for
convenience and shall not be considered in interpreting this Agreement or as
amplifying or limiting any of its content. Words in this Agreement which import
the singular connotation shall be interpreted as plural, and words which import
the plural connotation shall be interpreted as singular, as the identity of the
parties or objects referred to may require.

         24.2 Unless expressly defined herein, words having well known technical
or trade meanings shall be so construed. All listing of items shall not be taken
to be exclusive, but shall include other items, whether similar or dissimilar to
those listed, as the context reasonably requires.

         24.3 Except as set forth to the contrary herein, any right or remedy of
Lessee or Qwest shall be cumulative and without prejudice to any other right or
remedy, whether contained herein or not.

         24.4 This Agreement has been fully negotiated between and jointly
drafted by the parties, each of whom had full opportunity to consult with
counsel before execution.

         24.5 In the event of a conflict between the provisions of this
Agreement and those of any Exhibit, the provisions of this Agreement shall
prevail and such Exhibit shall be corrected accordingly.

         24.6 All actions, activities, consents, approvals and other
undertakings of the parties in this Agreement shall be performed in a reasonable
and timely manner, it being expressly acknowledged and understood that time is
of the essence in the performance of obligations required to be performed by a
date expressly specified herein. Except as specifically set forth herein, for
the purpose of this Section the normal standards of performance within the
telecommunications industry in the relevant market shall be the measure of
whether a party's performance is reasonable and timely.

25.      REPRESENTATIONS

         25.1     Each party represents that:

               (a) It has the full right and authority to enter into, execute,
          deliver and perform its obligations under this Agreement;


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               (b) This Agreement constitutes a legal, valid and binding
          obligation enforceable against such party in accordance with its
          terms, subject to bankruptcy, insolvency, creditors' rights and
          general equitable principles; and

               (c) At the time of execution, this Agreement does not violate any
          applicable existing state, federal, city or county law.

26.      PUBLICITY, NAME AND MARKS.

         26.1 Notwithstanding the foregoing, no publicity regarding the
existence and/or terms of this Agreement may occur without Qwest's prior express
written consent, and such written consent, if granted, may be granted only by
Qwest's Senior Vice President of Corporate Communications. The content and
timing of any press releases and all other publicity regarding the subject
matter of this Agreement or Lessee's relationship with Qwest, if authorized,
shall be mutually agreed upon by the parties in advance. Notwithstanding
anything to the contrary, Lessee may not make any disclosure to any other person
(other than to those Lessee's representatives or agents who have a need to know
such information and who agree to maintain the confidentiality thereof), or any
public announcement regarding this Agreement or any relation between Lessee and
Qwest, without Qwest's prior written consent, which consent shall not be
unreasonably withheld. In addition, neither Party shall use any trademark,
service mark, brand name, copyright, patent, or any other intellectual property
of the other Party or its respective Affiliates without the other Party's prior
written consent and (a) in the case of Qwest, with the prior written consent of
the Senior Vice President of Corporate Communications; or (b) in the case of
Lessee, with the prior written consent of its General Counsel.

27.      ASSIGNMENT

         27.1 This Agreement shall be binding on each party and its respective
Affiliates, successors, and assigns. Neither party shall assign, sell or
transfer this Agreement or the right to lease the leased Fiber hereunder,
whether by operation of law or otherwise, [*]. Notwithstanding the foregoing, an
assigning party may assign or transfer all of its rights and obligations under
this Agreement to any partnership, corporation or other entity which controls,
is controlled by, or is under common control with the assigning party or its
parent (control being defined for such purposes as ownership of at least 50% of
the equity interests in, or the power to direct the management of, the relevant
entity) or to any partnership, corporation or other entity resulting from a
merger or consolidation with the assigning party or its parent, or to any person
or entity which acquires substantially all the assets of the assigning party as
a going concern. Any attempted assignment in violation hereof shall be null and
void.

28.      NO PERSONAL LIABILITY

         28.1 Each action or claim against any party arising under or relating
to this Agreement shall be made only against such party as a corporation, and
any liability relating thereto shall be enforceable only against the corporate
or limited liability


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company assets of such party. No party shall seek to pierce the corporate or
limited liability company veil or otherwise seek to impose any liability
relating to, or arising from, this Agreement against any shareholder, employee,
officer or director of the other party.

29.      RELATIONSHIP OF THE PARTIES

         29.1 The relationship between Lessee and Qwest shall not be that of
partners, agents, or joint venturers. Nothing in this Agreement shall be deemed
to constitute a partnership or agency agreement between the parties for any
purposes, including but not limited to federal income tax purposes. Lessee and
Qwest, in performing any of their obligations hereunder, shall be independent
contractors or independent parties and shall discharge their contractual
obligations at their own risk.

30.      NO THIRD PARTY BENEFICIARIES

         30.1 This Agreement does not provide and is not intended to provide any
third party beneficiaries, including but not limited to Lessee's end users or
customers, with any remedy, claim, reimbursement, cause of action or other right
or privilege.

31.      SEVERABILITY

         31.1 If any term, covenant or condition contained herein shall, to any
extent, be invalid or unenforceable in any respect under the laws governing this
Agreement, the remainder of this Agreement shall not be affected thereby, and
each term, covenant or condition of this Agreement shall be valid and
enforceable to the fullest extent permitted by law.

32.      COUNTERPARTS

         32.1 This Agreement may be executed in one or more counterparts, all of
which taken together shall constitute one and the same instrument.

33.      ENTIRE AGREEMENT; AMENDMENT

         33.1 This Agreement constitutes the entire and final agreement and
understanding between the parties with respect to the subject matter hereof and
supersedes all prior agreements relating to the subject matter hereof, which are
of no further force or effect.

         33.2 The Appendices and Exhibits referred to herein are integral parts
hereof and are made a part of this Agreement.

         33.3 This Agreement may only be modified or supplemented by an
instrument in writing executed by a duly authorized representative of each
party.


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In confirmation of their consent and agreement to the terms and conditions
contained in this Agreement and intending to be legally bound hereby, the
parties have executed this Agreement as of the date first above written.

                            (2)  QWEST COMMUNICATIONS CORPORATION

                  By:__________________________________________
                  Name:  _______________________________________
                  Title:    _______________________________________

                                 (a)  LESSEE:  COGENT
                                 COMMUNICATIONS, INC.

                  By:__________________________________________
                  Name:  _______________________________________
                  Title:    _______________________________________




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List of Exhibits:

o  Exhibit A:     List of Rings and Building Laterals Available in Qwest Network

o  Exhibit A-1:   Description of System Route in Qwest Network for Rings

o  Exhibit A-2:   Description of System Route in Qwest Network for Building
                  Laterals

o  Exhibit B:     Technical Specifications

o  Exhibit C:     Additional Terms and Conditions

o  Exhibit D:     Technical Specifications Lucent Technologies

o  Exhibit E:     Pricing

THIS AGREEMENT INCLUDES METRO FIBERS AND LATERALS AND THUS ALL EXHIBITS ARE
APPLICABLE.



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                                    EXHIBIT A

                     B.           QWEST METRO NETWORK


                                       [*]

                    [19 pages describing Qwest Metro Network]



                                       A2-1

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                                   EXHIBIT B:

                            TECHNICAL SPECIFICATIONS

                                       [*]

               [11 pages describing the technical specifications]






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                                   EXHIBIT C:

                                   (i) ADDITIONAL TERMS AND CONDITIONS

The following provisions shall be a part of the Agreement only if Qwest has
specifically designated in EXHIBIT A hereto that any Segment the leased Fibers
in the System Route is part of a Qwest metropolitan dark fiber optic
telecommunications network. The additional provisions of this Exhibit apply only
to that portion of the leased Fibers that are contained within in a
Qwest-designated metropolitan dark fiber optic telecommunication network. The
provisions of this Exhibit do not apply to any other leased Fiber Segments,
including, but not limited to long haul or local access Segments.

1.       ADDITIONAL DOCUMENTATION

         1.1 Qwest shall provide Lessee with the following documentation within
ninety (90) days of the applicable Acceptance Date

                  (a) Technical specifications of the fiber cable and associated
splices and other equipment placed in the Qwest Network along the System Route
relevant to the Leased Fibers;

                  (b) a copy of the test results of the Leased Fibers

                  (c) System route drawings

2.       CONNECTING POINTS

         2.1 Qwest shall provide Lessee with access to the Lessee Fibers at the
Connecting Points set forth in an Order. All connections shall be performed by
Qwest, in accordance with Qwest's applicable specifications and operating
procedures.

         2.2 Subject to all applicable Underlying Rights Requirements, Qwest
shall provide Lessee with reasonable access to the Connecting Points set forth
in an Order, but only if accompanied by a Qwest representative(s) in accordance
with Qwest's standard operating procedures. Lessee shall pay Qwest's Costs for
providing such representative(s).

         2.3 Neither Qwest nor Lessee shall have any limitations on the types of
electronics or technologies employed to use the Leased Fiber; however, Lessee's
electronics or technologies must comply with Qwest safety procedures and shall
not interfere with the Qwest Network.

         2.4 In placing a Request, Lessee shall submit the Request for any
connection at least ninety (90) days in advance of the date needed by Lessee.
The Parties must agree to an Order before provisioning may begin. Upon Qwest
approval, any construction work will be restricted to a Planned System Work
Period, unless otherwise agreed to in writing. The [*] of such additional
connections will fully be paid by Lessee. Lessee shall pay Qwest's Costs for
each additional connection within thirty (30) days of the date of Qwest's
invoice and as provided in Section 4 of the Agreement. It is the responsibility
of Lessee to obtain all governmental and



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other approvals and consents necessary for the delivery of the leased Fibers to
any additional Connecting Point.

3.       LIMITED PASS-THROUGH FIBER WARRANTY

         3.1 Beginning on the Effective Date, and ending twelve (12) months
thereafter, Qwest warrants that, except for those items that are supplied or
specified by Lessee, at the time of Delivery the Lessee Fibers complies with the
specifications set forth in EXHIBIT D. If within twelve (12) months following
the Effective Date, the Lessee Fibers do not meet the warranty described above,
Lessee shall notify Qwest in writing. Upon receipt of written notice from
Lessee, Qwest will inspect the subject leased Fiber to confirm any alleged
defect(s) and take commercially reasonable steps to correct such defects.

         3.2 Qwest will pass through to Lessee all manufacturers' warranties
that pertain to the leased Fibers to the extent that they are transferable.
Qwest's liability to Lessee under the manufacturers' warranty shall not exceed
the terms, conditions and scope of the manufacturer's warranty and shall not
exceed the terms and conditions of the Agreement. In addition to the limitation
of liability set forth in Section 11 of the Agreement, in no event shall Qwest
be liable to Lessee for any direct, exemplary, special, consequential or
punitive damages, including but not limited to, lost profits or the cost of
providing alternative service.

         3.3 Lessee's sole and exclusive remedy for breach of the warranty
mentioned in the preceding paragraph shall be repair and/or replacement of the
portions of the Lessee Fibers found to be defective, but only if such repairs
and/or replacement are approved by the manufacturer of the fiber pursuant to the
manufacturer's warranty.





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                                   EXHIBIT D:

                                      (ii) FIBER SPECIFICATIONS

                                       [*]

                   [12 pages describing fiber specifications]





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                                    EXHIBIT E

                                     PRICING

                                       [*]

                           [1 page describing pricing]