Microsoft KB Archive/247066

= Windows NT DHCP Server May Not Add BAD_ADDRESS Entries When Receiving DHCP Decline Messages =

Article ID: 247066

Article Last Modified on 11/1/2006

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APPLIES TO


 * Microsoft Windows NT 4.0 Service Pack 4
 * Microsoft Windows NT 4.0 Service Pack 5
 * Microsoft Windows NT 4.0 Service Pack 6
 * Microsoft Windows NT 4.0 Service Pack 6a

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This article was previously published under Q247066



SYMPTOMS
When a third-party Dynamic Host Configuration Protocol (DHCP) client detects that the Transport Control Protocol/Internet Protocol (TCP/IP) address received from a DHCP server already exists on the Local Area Network (LAN), the DHCP client may send a DHCP decline message to the DHCP server. However, the DHCP server may not add a BAD_ADDRESS entry in the DHCP database for this duplicate TCP/IP address.



CAUSE
This problem can occur when a Windows NT 4.0-based server with Service Pack 4 (SP4) or later receives a DHCP decline message that does not conform to Request for Comment (RFC) 2131.



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

This problem is corrected in Microsoft Windows 2000.



MORE INFORMATION
Windows NT 4.0-based DHCP servers running SP4 or later do not add a BAD_ADDRESS entry in the DHCP database when they receive a DHCP decline message from a DHCP client that conforms to RFC 1541.

RFC 2131 specifies the "Requested IP address" field in the Option Field (0x32 hexadecimal, or 50 decimal) of the DHCP decline message, and RFC 1541 specifies the "Requested IP address" field in the ciaddr field of the DHCP decline message. A Windows NT 4.0-based DHCP server does not add BAD_ADDRESS to the DHCP database for a duplicate TCP/IP address if the "Requested IP address" is not present in the Option field of a DHCP decline message.

Third-party print servers that do not conform to RFC 2131 are mostly affected by this issue. Windows NT-based DHCP clients are not affected. For more information about DHCP server behavior when receiving DHCP decline messages, see RFC 2131, section 4.3.3.

