Multihomed DHCP clients may cause "bad_address" entry on a DHCP Server in Windows 2000 (325919)

SYMPTOMS

A "bad_address" entry may be generated on a DHCP server. This problem may occur when the following conditions are true:

You have one multihomed DHCP client and one DHCP server.
Both network adaptors on the DHCP client and the network adaptor on the DHCP server are connected to the same segment.
Both network adaptors on the DHCP client are configured to automatically obtain an IP address.
Conflict detection is enabled on the DHCP server.

If you run the following commands on the DHCP client, one "bad_address" entry is generated on the DHCP server:

ipconfig /release
ipconfig /renew

This "bad_address" entry is the IP address that was previously assigned to the second network adaptor on the DHCP client. If you run the two commands again, another "bad_address" entry is generated on the DHCP server. In this manner, all available IP addresses in the scope become bad addresses. This could cause the DHCP server to be out of service for the scope.

CAUSE

Assume that nnn.nn.1.1 is assigned to the first network adaptor on the DHCP client and that nnn.nn.1.2 is assigned to the second network adaptor on the DHCP client. After you run the following command on the DHCP client, nnn.nn.1.1 is still assigned to the first network adaptor on the DHCP client:

ipconfig /release
ipconfig /renew

The DHCP server also tries to assign nnn.nn.1.2 to the second network adaptor. Because conflict detection is enabled on the DHCP server, the DHCP server tries to ping nnn.nn.1.2 before it assigns nnn.nn.1.2 to the second network adaptor on the DHCP client. Therefore, the DHCP server sends the Internet Control Message Protocol (ICMP) ECHO packet to the media access control (MAC) address of the second network adaptor on the DHCP client. The DHCP client receives the ICMP ECHO packet and passes it to the upper level. The DHCP client sends the ICMP ECHO reply packet to the DHCP server from the first network adaptor. The DHCP server then marks nnn.nn.1.2 as "bad_address".

RESOLUTION

Service pack information

To resolve this problem, obtain the latest service pack for Microsoft Windows 2000. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

260910 How to Obtain the Latest Windows 2000 Service Pack

Hotfix information

A supported hotfix is now available from Microsoft, but it is only intended to correct the problem that is described in this article. Only apply it to systems that are experiencing this specific problem. This hotfix may receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next Windows 2000 service pack that contains this hotfix.

To resolve this problem immediately, contact Microsoft Product Support Services to obtain the hotfix. For a complete list of Microsoft Product Support Services telephone numbers and information about support costs, visit the following Microsoft Web site:

http://support.microsoft.com/contactus/?ws=support

Note In special cases, charges that are ordinarily incurred for support calls may be canceled if a Microsoft Support Professional determines that a specific update will resolve your problem. The usual support costs will apply to additional support questions and issues that do not qualify for the specific update in question.

The English version of this hotfix has the file attributes (or later file attributes) 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
   --------------------------------------------------------
   04-Sep-2002  06:11  5.0.2195.6044  118,896  Afd.sys
   04-Sep-2002  09:07  5.0.2195.6020  105,232  Msafd.dll        
   04-Sep-2002  09:07  5.0.2195.6045  313,296  Tcpip.sys
   30-Jul-2001  12:15  5.0.2195.3988   16,240  Tdi.sys
   04-Sep-2002  09:07  5.0.2195.4874   17,680  Wshtcpip.dll