After you install Service Pack 1 (SP1) for Windows XP, your
computer may drop virtual private network (VPN) connections that are using Point-to-Point Tunneling Protocol (PPTP) after about 55
This behavior may occur if Internet Connection Sharing is
turned on for one or more of your network connections.
Service pack information
To resolve this problem, obtain the latest service pack for Microsoft Windows XP. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:
How to obtain the latest Windows XP service pack
A supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing this specific problem. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next software update that contains this hotfix.
If the hotfix is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. If this section does not appear, contact Microsoft Customer Service and Support to obtain the hotfix. Note
If additional issues occur or if any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, visit the following Microsoft Web site: Note
The "Hotfix download available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language. The English version of
this fix has the file attributes (or later) that are listed in the following
table. The dates and times for these files are listed in coordinated universal
time (UTC). When you view the file information, it is converted to local time.
To find the difference between UTC and local time, use the Time Zone
tab in the Date and Time tool in Control Panel.
Date Time Version Size File name
14-Nov-2002 14:16 5.1.2600.1142 154,112 Netman.dll
14-Nov-2002 14:16 5.1.2600.1142 435,200 Ipnathlp.dll
To work around this problem, turn off Internet Connection
Sharing to prevent VPN connections from disconnecting. To do this:
- Open Network Connections.
- Right-click the dial-up connection, local area network
connection, PPPoE connection, or VPN connection that you no longer want to
share, and then click Properties.
- Click the Advanced tab.
- Clear the Allow other network users to connect
through this computer's Internet connection check box, and then click
has confirmed that this is a problem in the Microsoft products that are listed
at the beginning of this article.
This problem was first corrected in Microsoft Windows XP Service Pack 2.