Microsoft KB Archive/287673

= The Packet Filter Does Not Enable the Renewal of an External IP Address =

Article ID: 287673

Article Last Modified on 1/18/2006

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APPLIES TO


 * Microsoft Small Business Server 2000 Standard Edition
 * Microsoft BackOffice Server 2000

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This article was previously published under Q287673



SYMPTOMS
After you release the Internet Protocol (IP) address on the external network adaptor of a multiple-homed server with the ipconfig /release command, the IP address cannot be renewed by using the ipconfig /renew command.

You may receive the following error message, where X is the number of the network connection for the external network interface card (NIC):

The following error occurred when renewing adapter Local Area Connection X: DHCP Server unreachable.

NOTE: This problem only occurs on a Small Business Server 2000-based server, or on a BackOffice 2000 Server-based server that runs Microsoft Internet Security and Acceleration (ISA) Server.



CAUSE
This problem can occur because ISA Server puts a Dynamic Host Configuration Protocol (DHCP) filter on the external network adaptor. After the IP address is released from this adaptor, it can either have an IP address of 0.0.0.0, or an auto-assigned IP address. ISA Server does not enable this network adaptor to receive DHCP packets, therefore, it is unable to renew an IP address lease.



WORKAROUND
To work around this problem, use the following method:
 * 1) Click Start, point to Programs, point to Microsoft ISA Server, and then click ISA Management.
 * 2) Expand Servers and Arrays, expand Your Server, expand Access Policy, and select IP Packet Filters.
 * 3) In the right window labeled &quot;Available Packet Filters&quot;, select DHCP Client, and click Configure a Packet Filter.
 * 4) On the DHCP Client Properties page, and under the General tab, click Enable this filter.
 * 5) Click Start, point to Programs, click Administrative Tools, and then click Services.
 * 6) Right-click Microsoft ISA Server Control, and then click Stop.
 * 7) A window is displayed that lists the following services that can be stopped:

Microsoft Scheduled Cache Content Download

Microsoft Web Proxy

Microsoft Firewall

Click Yes to stop these services.
 * 1) At a command prompt, type ipconfig /renew
 * 2) The IP address is renewed. Because the filter is now in place, the preceding steps are not needed again to release and renew the IP address.

NOTE: If the IP address is ever released, it will not be possible to run the ipconfig /renew command without disabling the packet filters or ISA.
 * 1) Restart the services that you stopped in steps 6 and 7.



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

Keywords: kbenv kbip kbprb KB287673

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