<PAGE>
                                                                 Exhibit 10.01

               AMENDMENT NUMBER TWO TO IRU CAPACITY AGREEMENT

This Amendment Number Two ("Amendment"), effective September 30, 1999 (the
"Effective Date"), amends the IRU Capacity Agreement ("Agreement") entered
into as of December 19, 1998 between AT&T Corp. ("AT&T"), a New York
corporation with offices at 295 North Maple Avenue, Basking Ridge, New Jersey
07920, and At Home Corporation, ("@Home"), a Delaware corporation with a
principal place of business located at 425 Broadway, Redwood City, CA 94063,
as previously amended, as follows:


                                 BACKGROUND


Pursuant to the Agreement, AT&T granted to @Home an indefeasible right to use
optical fibers and dedicated circuit capacity on the AT&T Network.

Pursuant to Section 3.1 of the Agreement, AT&T agreed to assist @Home's
transition to the AT&T Network, during the period from January 1, 1999 through
Acceptance of the Phase Two Services, by assuming @Home's rights and
obligations under the Sprint ATM Arrangement.

The fifth sentence of Section 3.1 of the Agreement currently provides: "In the
event that AT&T incurs charges under the Sprint ATM Arrangement in excess of
nine million dollars, @Home will pay the amount of such excess to AT&T as an
Assumption Fee, except if AT&T does not deliver the Phase Two Capacity by the
Phase Two Commitment Date the charges incurred under the Sprint ATM
Arrangement from April 1, 1999 through the date on which AT&T delivers the
Phase Two Capacity will not be counted in calculating any Assumption Fee."

THEREFORE, the parties hereby amend the Agreement as follows:


                                  AMENDMENT

1.   In Section 3.1, delete the existing fifth sentence, and insert the
following new sentence in its place: "In the event that AT&T incurs charges
under the Sprint ATM Arrangement in excess of fifteen million five hundred
thousand dollars ($15,500,000), @Home will pay the amount of such excess to
AT&T as an Assumption Fee."

2.   In Section 5.1, delete "and four million dollars ($4,000,000) (the
"Additional IRU Fee")" and insert in its place "and eleven million nine
hundred ninety-four thousand three hundred dollars ($11,994,300) (the
"Additional IRU Fee")".

3.   In Exhibit I (Payment Terms), delete "@Home shall pay the Additional IRU
Fee on July 1, 1999" and insert in its place "@Home shall pay the Additional
IRU Fee according to the following schedule: $4,000,000 by October 4, 1999,
$1,494,300 by October 8, 1999, and $6,500,000 by November 1, 1999."

4.   Except as modified above, all other terms and conditions of the Agreement
remain in full force and effect. Terms used and not defined herein will have
the meanings assigned to them in the Agreement. In the event of any conflict
between the provisions of the Amendment and the Agreement, the provisions of
this Amendment shall govern.

IN WITNESS WHEREOF, authorized representatives of the parties have executed
this Amendment as of the Effective Date.


AT&T CORP.                           AT HOME CORPORATION



By:                                  By:
   ---------------------                ---------------------

Title:                               Title:
      ------------------                   ------------------

Date:                                Date:
     -------------------                  -------------------