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Q124026: DHCP Requests Fail on Logically Multihomed Server (Single NIC)

Article: Q124026
Product(s): Microsoft Windows NT
Version(s): 3.5,3.51,4.0
Operating System(s): 
Keyword(s): kbnetwork
Last Modified: 04-FEB-2002

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The information in this article applies to:

- Microsoft Windows NT Workstation versions 3.5, 3.51, 4.0 
- Microsoft Windows NT Server versions 3.5, 3.51, 4.0 
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SYMPTOMS
========

Windows NT Dynamic Host Configuration Protocol (DHCP) client IP address lease
requests fails on a multihomed server configured with multiple logical IP
networks on a single network interface card (NIC).

This logical multihomed system is a Windows NT Server with a single NIC
configured with multiple IP addresses for one physical segment. If this server
is also functioning as a DHCP server with active scopes configured for each
logical IP network, DHCP client requests are filled until the scope defining the
first logical IP address pool is exhausted. Further DHCP client requests fail to
be filled from the pool of IP addresses available from the second or higher
logical IP network scopes.

RESOLUTION
==========

To resolve this problem, install a NIC in the DHCP server for each logical
segment. Each NIC should be connected to the same physical segment and assigned
only one logical IP address. As DHCP scopes are created they will be made
available to the clients via the network interface card at this IP network. Also
verify that IP routing has been enabled on this multihomed DHCP server.

STATUS
======

This is by design. This forces clients residing on a physical segment to acquire
IP addresses that are within the same IP network scope.

MORE INFORMATION
================

Microsoft Windows NT Server 4.0 Service Pack 2 includes the ability to create
DHCP superscopes, which allows the administrator to group scopes together. This
eliminates the need of multiple adapters to service multiple scopes.

For more information on superscopes, please see the following article in the
Microsoft Knowledge Base:

Article : Q161571 Description: Using DHCP "Superscopes" to Serve Multiple Logical
Subnets

Additional query words: prodnt adapter wfw wfwg tcp ip multinet

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Keywords          : kbnetwork 
Technology        : kbWinNTsearch kbWinNTWsearch kbWinNTW400 kbWinNTW400search kbWinNT351search kbWinNT350search kbWinNT400search kbWinNTW350 kbWinNTW350search kbWinNTW351search kbWinNTW351 kbWinNTSsearch kbWinNTS400search kbWinNTS400 kbWinNTS351 kbWinNTS350 kbWinNTS351search kbWinNTS350search
Version           : :3.5,3.51,4.0

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