Multihomed DHCP Server Assigns Duplicate IP Addresses (310844)


The information in this article applies to:

  • Microsoft Windows 2000 Server SP1
  • Microsoft Windows 2000 Server SP2
  • Microsoft Windows 2000 Advanced Server SP1
  • Microsoft Windows 2000 Advanced Server SP2
This article was previously published under Q310844

SYMPTOMS

A multihomed DHCP server may assign duplicate IP addresses.

CAUSE

This problem can occur if more than one of the network adapters in the multihomed DHCP server is connected to the same physical network segment.

WORKAROUND

To resolve this issue, use either of the following methods.

Method 1

Unbind the DHCP service from all but one of the network adapters that are connected to the same physical network segment.

Method 2

Disconnect all but one network adapter from that physical network segment.

STATUS

Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article.

MORE INFORMATION

You can observe this problem by enabling DHCP logging. The following portion of a DHCP log demonstrates this problem:

...
10,07/24/01,12:51:14,Assign,172.16.10.109,cli103.ponpon.local,5241532000C04FA03430000000000000
10,07/24/01,12:51:17,Assign,172.16.10.109,cli103.ponpon.local,5241532000C04FA03430000001000000
...
10,07/24/01,12:51:21,Assign,172.16.10.109,cli104.ponpon.local,5241532000C04F0F96F9000001000000
...
10,07/24/01,12:52:28,Assign,172.16.10.109,cli101.ponpon.local,524153200000864DE276000000000000
10,07/24/01,12:52:31,Assign,172.16.10.109,cli101.ponpon.local,524153200000864DE276000001000000
...
10,07/24/01,12:59:15,Assign,172.16.10.109,cli1.,00B0D0A9C291
...
13,07/24/01,13:06:47,Conflict,172.16.10.109,BAD_ADDRESS,
13,07/24/01,13:06:47,Conflict,172.16.10.109,BAD_ADDRESS,
...

Note that the 172.16.10.109 IP address is being assigned to different clients over and over without first being released, which then causes a conflict, and this conflict is reported if conflict detection has been enabled on the DHCP server.
Modification Type:MajorLast Reviewed:12/4/2003
Keywords:kbbug kbenv kbnetwork kbnofix KB310844
©2003 Microsoft Corporation. All rights reserved.