Microsoft KB Archive/147872

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Unable to Lease IP Address from DHCP Server

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Q147872

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The information in this article applies to:


 * Microsoft Windows 95

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SYMPTOMS
When you are using Windows 95 with a DHCP server to assign an IP address, you may receive the following error message if DHCP messages have not been disabled in Windows 95:

This DHCP client was unable to obtain an IP network address from a DHCP server.

If DHCP messages have been disabled, you may not see the error message even though an IP address was not obtained.

This error can occur if the DHCP server does not respond to a DHCP request within two seconds.

RESOLUTION
This issue is resolved by the following updated file for Windows 95, and later versions of this file:

  VDHCP.386  version 4.00.951  dated 2/12/96  27,985 bytes The updated version of this file is included in the Windows Sockets 2.0 update for Windows 95. For information on obtaining this update, see the following article in the Microsoft Knowledge Base:

"Q182108 Availability of Windows Sockets 2.0 for Windows 95"

STATUS
Microsoft has confirmed this to be a problem in Microsoft Windows 95. An update to address this problem is now available, but is not fully regression tested and should be applied only to computers experiencing this specific problem. Unless you are severely impacted by this specific problem, Microsoft does not recommend implementing this update at this time. Contact Microsoft Technical Support for additional information about the availability of this update.

This issue is resolved in Microsoft Windows 98.

MORE INFORMATION
When requesting an IP address from a DHCP server, Windows 95 times out the requests at two-second intervals. After a timeout, the request is re- issued. If the timeout has expired before the server responds, the response is discarded and the client waits for a response to its latest request. This process continues through four retries, at which time the error message stated above is generated.

This problem does not occur with MSTCP-32 for Windows for Workgroups because it uses a default timeout of four seconds.

This problem is known to occur when you are using DHCP servers that implement address protection at the server. In particular, the problem occurs if it takes the server more than two seconds to verify whether an address that it is preparing to issue is already in use or not.

Address protection is the process of determining whether an address is in use by another computer before a client uses it. Note that Microsoft DHCP clients implement address protection at the client.

For additional information about issues resolved by updates to this component, please see the following articles in the Microsoft Knowledge Base:

Q158713 Fatal Exception Error Using DHCP

Q147872 Unable to Lease IP Address from DHCP Server

Q140460 Dial-Up Networking Does Not Obtain an IP Address For additional information about Windows 95 updates, please see the following article in the Microsoft Knowledge Base:

"Q161020 Implementing Windows 95 Updates" Additional query words: tcp/ip tcp protocol

Keywords : kberrmsg kbnetwork kbpolicy win95

Issue type : kbprb

Technology : kbWin95search kbWin95