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                                                                   EXHIBIT 10.6A


                                                                       EXECUTION

                               NETWORK PLUS, INC.

                               FIRST AMENDMENT TO
                          CREDIT AND GUARANTY AGREEMENT

         This FIRST AMENDMENT, dated as of February 9, 2001 (this "AMENDMENT"),
to the Credit and Guaranty Agreement, dated as of September 27, 2000 (as amended
through the date hereof, the "CREDIT AGREEMENT"), by and among NETWORK PLUS,
INC., a Massachusetts corporation ("COMPANY"), NETWORK PLUS CORP., a Delaware
corporation ("HOLDINGS"), the Lenders party hereto from time to time, GOLDMAN
SACHS CREDIT PARTNERS L.P. ("GSCP"), as a Joint Lead Arranger (in such capacity,
a "JOINT LEAD ARRANGER"), Book Runner (in such capacity,"BOOK RUNNER") and as
Syndication Agent (in such capacity, "SYNDICATION AGENT"), FLEET SECURITIES,
INC., ("FLEET SECURITIES"), as a Joint Lead Arranger (in such capacity, a "JOINT
LEAD ARRANGER"), DLJ BRIDGE FINANCE, INC., as Documentation Agent (in such
capacity, "DOCUMENTATION AGENT") and FLEET NATIONAL BANK, as Administrative
Agent (together with its permitted successors and assigns in such
capacity, "ADMINISTRATIVE AGENT") and as Collateral Agent (together with its
permitted successors and assigns in such capacity, "COLLATERAL AGENT").
Capitalized terms used herein not otherwise defined herein or otherwise amended
hereby shall have the meanings ascribed thereto in the Credit Agreement.

                                    RECITALS:

         WHEREAS, Company and Holdings have requested that Requisite Lenders
agree to amend the Credit Agreement, subject to the terms and conditions set
forth herein, to (i) allow for the cash collateralization of letters of credit
with Loans, (ii) account for a one-time charge Company and Holdings will be
taking in the fiscal quarter ended December 31, 2000 relating to a write-off of
an investment in securities of NorthPoint Communications Group, Inc. and (iii)
make certain other modifications; and

         NOW, THEREFORE, in consideration of the premises and the agreements,
provisions and covenants herein contained, the parties hereto agree as follows:

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SECTION 1. AMENDMENTS TO CREDIT AGREEMENT

         1.1 AMENDMENTS TO SECTION 1: DEFINITIONS.

                  A. Section 1.1 of the Credit Agreement is hereby amended by
adding thereto the following definitions in proper alphabetical order:

                           "FIRST AMENDMENT" means the First Amendment dated
                  February 9, 2001 to this Agreement by and among Company,
                  Holdings, Lenders as of the date of such amendment, the Joint
                  Lead Arrangers, Book Runner, Syndication Agent, Documentation
                  Agent, Administrative Agent and Collateral Agent."

                           "FIRST AMENDMENT CLOSING DATE" has the meaning
                  assigned to that term in the First Amendment."

                  B. Section 1.1 of the Credit Agreement is hereby further
amended by adding the following proviso at the end of clause (e) in the
definition of "Consolidated Net Income":

                           ";plus (iii) solely for the purposes of subsection
                  6.6(c) and solely for any relevant period of measurement under
                  such subsection and only to the extent otherwise deducted in
                  calculating net income, the amount equal to the write-off
                  taken by the Company and Holdings in the fiscal quarter ended
                  December 31, 2000 of an investment in the securities of
                  Northpoint Communications Group, Inc."

         1.2 AMENDMENTS TO SECTION 6: NEGATIVE COVENANTS.

                  A. Subsection 6.2(i) is hereby amended by deleting the
parenthetical clause "(provided such cash collateral shall not consist of monies
funded hereunder)" contained therein.

SECTION 2. CONDITIONS PRECEDENT TO EFFECTIVENESS

         2.1 The effectiveness of the amendments set forth at Section 1 hereof
are subject to the satisfaction, or waiver, of the following conditions on or
before the date hereof (the "FIRST AMENDMENT CLOSING DATE"):

                  (a) The Company, Holdings and the Requisite Lenders shall have
indicated their consent by the execution and delivery of the signature pages
hereof to the Administrative Agent.


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                  (b) As of the First Amendment Closing Date, the
representations and warranties contained herein and in the other Credit
Documents shall be true, correct and complete in all respects on and as of the
First Amendment Closing Date to the same extent as though made on and as of that
date, except to the extent such representations and warranties specifically
relate to an earlier date, in which case such representations and warranties
shall have been true, correct and complete in all respects on and as of such
earlier date.

                  (c) As of the First Amendment Closing Date, no event shall
have occurred and be continuing that would constitute an Event of Default or a
Default.

                  (d) The Administrative Agent and Lenders shall have received
such other documents and information regarding Credit Parties and the Credit
Agreement as the Administrative Agent or Lenders may reasonably request.

SECTION 3. REPRESENTATIONS AND WARRANTIES

         3.1 In order to induce Lenders to enter into this Amendment, each
applicable Credit Party represents and warrants to each Lender, as of the date
hereof and upon giving effect to this Amendment:

                  (a) as of the date hereof, there exists no Event of Default
         under the Credit Agreement; and

                  (b) that the representations and warranties contained in each
         of the Credit Documents is true, correct and complete in all respects
         on and as of the date hereof to the same extent as though made on and
         as of that date, except to the extent such representations and
         warranties specifically relate to an earlier date, in which case such
         representations and warranties shall have been true, correct and
         complete in all respects on and as of such earlier date.

SECTION 4. ACKNOWLEDGMENT AND CONSENT

                  4.1 Holdings has (i) guaranteed the Obligations and (ii)
created Liens in favor of Lenders on certain Collateral to secure its
obligations under Section 7 of the Credit Agreement. Holdings is referred to
herein as the "CREDIT SUPPORT PARTY", and the Credit Agreement and the Pledge
and Security Agreement, dated as of September 27, 2000, between the Company,
each of the grantors party thereto and Fleet National Bank, as Collateral Agent
(as such may be amended, supplemented or modified) (the "PLEDGE AND SECURITY
AGREEMENT") are collectively referred to herein as the "CREDIT SUPPORT
DOCUMENTS".


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                  4.2 The Credit Support Party hereby acknowledges that it has
reviewed the terms and provisions of the Credit Agreement and this Amendment and
consents to the amendment of the Credit Agreement effected pursuant to this
Amendment. The Credit Support Party hereby confirms that each Credit Support
Document to which it is a party or otherwise bound and all Collateral encumbered
thereby will continue to guarantee or secure, as the case may be, to the fullest
extent possible in accordance with the Credit Support Documents, the payment and
performance of all Guaranteed Obligations under the Credit Agreement Secured
Obligations (as such term is defined in the Pledge and Security Agreement) under
the Pledge and Security Agreement, as the case may be, including without
limitation the payment and performance of all such Guaranteed Obligations under
the Credit Agreement and Secured Obligations (as such term is defined in the
Pledge and Security Agreement) under the Pledge and Security Agreement in
respect of the Obligations of Company now or hereafter existing under or in
respect of the Credit Agreement, as amended by this Amendment, and grants to the
Collateral Agent a continuing lien on and security interest in and to all
Collateral as collateral security for the prompt payment and performance in full
when due of the Guaranteed Obligations under the Credit Agreement and the
Secured Obligations (as such term is defined in the Pledge and Security
Agreement) under the Pledge and Security Agreement (whether at stated maturity,
by acceleration or otherwise).

                  4.3 The Credit Support Party acknowledges and agrees that any
of the Credit Support Documents to which it is a party or otherwise bound shall
continue in full force and effect and that all of its obligations thereunder
shall be valid and enforceable and shall not be impaired or limited by the
execution or effectiveness of this Amendment. The Credit Support Party
represents and warrants that all representations and warranties contained in the
Credit Agreement, as amended by this Amendment, and the Credit Support Documents
to which it is a party or otherwise bound are true, correct and complete in all
material respects on and as of the First Amendment Closing Date to the same
extent as though made on and as of that date, except to the extent such
representations and warranties specifically relate to an earlier date, in which
case they were true, correct and complete in all material respects on and as of
such earlier date.

                  4.4 The Credit Support Party acknowledges and agrees that (i)
notwithstanding the conditions to effectiveness set forth in this Amendment,
such Credit Support Party is not required by the terms of the Credit Agreement
or any other Credit Document to consent to the amendments to the Credit
Agreement effected pursuant to this Amendment and (ii) nothing in the Credit
Agreement, this Amendment or any other Credit Document shall be deemed to
require the consent of such Credit Support Party to any future amendments to the
Credit Agreement.

SECTION 5. MISCELLANEOUS

                  5.1 This Amendment shall be binding upon the parties hereto
and their respective successors and assigns and shall inure to the benefit of
the parties hereto and the successors and assigns of Lenders. No Credit Party's
rights or obligations hereunder or any interest therein may be assigned or
delegated by any Credit Party without the prior written consent of all Lenders.


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                  5.2 In case any provision in or obligation hereunder shall be
invalid, illegal or unenforceable in any jurisdiction, the validity, legality
and enforceability of the remaining provisions or obligations, or of such
provision or obligation in any other jurisdiction, shall not in any way be
affected or impaired thereby.

                  5.3 On and after the First Amendment Closing Date, each
reference in the Credit Agreement to "this Agreement", "hereunder", "hereof",
"herein" or words of like import referring to the Credit Agreement, and each
reference in the other Credit Documents to the "Credit Agreement", "thereunder",
"thereof" or words of like import referring to the Credit Agreement shall mean
and be a reference to the Credit Agreement as amended by this Amendment.

                  5.4 Except as specifically amended by this Amendment, the
Credit Agreement and the other Credit Documents shall remain in full force and
effect and are hereby ratified and confirmed.

                  5.5 The execution, delivery and performance of this Amendment
shall not, except as expressly provided herein, constitute a waiver of any
provision of, or operate as a waiver of any right, power or remedy of any Agent
or Lender under, the Credit Agreement or any of the other Credit Documents.

                  5.6 Section headings herein are included herein for
convenience of reference only and shall not constitute a part hereof for any
other purpose or be given any substantive effect.

                  5.7 THIS AMENDMENT AND THE RIGHTS AND OBLIGATIONS OF THE
PARTIES HEREUNDER SHALL BE GOVERNED BY, AND SHALL BE CONSTRUED AND ENFORCED IN
ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW YORK.

                  5.8 This Amendment may be executed in any number of
counterparts, each of which when so executed and delivered shall be deemed an
original, but all such counterparts together shall constitute but one and the
same instrument. As set forth herein, this Amendment shall become effective upon
the execution of a counterpart hereof by each of the parties hereto and receipt
by Company, Holdings and Administrative Agent and Syndication Agent of written
or telephonic notification of such execution and authorization of delivery
thereof.

            [The remainder of this page is intentionally left blank.]


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         IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be
duly executed and delivered by their respective officers thereunto duly
authorized as of the date first written above.

                                       NETWORK PLUS, INC.


                                       By: /s/ Robert J. Cobuzzi
                                           ----------------------------------
                                           Name: Robert J. Cobuzzi
                                           Title: Executive V.P. & C.F.O.

CREDIT SUPPORT                         NETWORK PLUS CORP.
PARTIES:

                                       By: /s/ Robert J. Cobuzzi
                                           ----------------------------------
                                           Name: Robert J. Cobuzzi
                                           Title: Executive V.P. & C.F.O.


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                                       GOLDMAN SACHS CREDIT PARTNERS L.P., as
                                       Joint Lead Arranger, Book Runner,
                                       Syndication Agent and a Lender


                                       By: /s/ R. Wagner
                                           ------------------------------------
                                                    Authorized Signatory


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                                       FLEET NATIONAL BANK,
                                       as Administrative Agent, Collateral Agent
                                       and a Lender

                                       By: /s/ Kay H. Campbell
                                           ------------------------------------
                                           Name: Kay H. Campbell
                                           Title: Vice President


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                                       DLJ BRIDGE FINANCE, INC.,
                                       as Documentation Agent


                                       By: /s/ Eugene F. Martin
                                           ------------------------------------
                                           Name: Eugene F. Martin
                                           Title: Director


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                                       NETPLUS FUNDING, INC.
                                       as a Lender

                                       By: /s/ Eugene F. Martin
                                           ------------------------------------
                                           Name: Eugene F. Martin
                                           Title: Director


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                                       IBM CREDIT CORPORATION
                                       as a Lender

                                       By: /s/ Thomas S. Oureio
                                           ------------------------------------
                                           Name: Thomas S. Oureio
                                           Title: Manager of Credit


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