Multihomed DHCP Clients May Cause "Bad_Address" Entry on a DHCP Server in Windows NT 4.0 (328710)

SYMPTOMS

A "bad_address" entry may be generated on a DHCP server. This problem may occur if:

You have one multihomed DHCP client and one DHCP server.
Both network adapters on the DHCP client and the network adapter on the DHCP server are connected to the same segment.
Conflict detection is enabled on the DHCP server.

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

ipconfig /release
ipconfig /renew

This address is the IP address that was previously assigned to the second network adapter on the DHCP client. If you run the two commands again, another "bad_address" entry is generated on the DHCP server. In this manner, the DHCP client can make all available IP addresses in the scope bad addresses. This might 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 adapter on the DHCP client, and that nnn.nn.1.2 is assigned to the second network adapter on the DHCP client. After the following command is run on the DHCP client, nnn.nn.1.1 is still assigned to the first network adapter on the DHCP client:

ipconfig /release
ipconfig /renew

The DHCP server also tries to assign nnn.nn.1.2 to the second network adapter. 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 adapter on the DHCP client. Therefore, the DHCP server sends the ICMP ECHO packet to the MAC address of the second network adapter on the DHCP client. The DHCP client then receives the ICMP ECHO packet, and passes it up to the upper level. The DHCP client sends the ICMP ECHO reply packet to the DHCP server from the first network adapter. The DHCP server then marks nnn.nn.1.2 as bad_address.

RESOLUTION

A supported fix is now available from Microsoft, but it is only intended to correct the problem that is described in this article. Apply it only to computers that are experiencing this specific problem.

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

http://support.microsoft.com/default.aspx?scid=fh;EN-US;CNTACTMS

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 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
   -----------------------------------------------------
   03-Sep-2002  00:59  4.0.1381.7192  174,960  Tcpip.sys

NOTE: Because of file dependencies, this hotfix requires Microsoft Windows NT 4.0 Service Pack 6a.

Multihomed DHCP Clients May Cause "Bad_Address" Entry on a DHCP Server in Windows NT 4.0 (328710)

SYMPTOMS

CAUSE

RESOLUTION

STATUS