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chickeninabiscuit
Asked: 2009-07-14 16:59:53 +0800 CST

Windows server 2003 suddenly unable to connect to anything?

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Our windows 2003 server has stopped all connectivity.

It's on 192.168.10.14. Our firewall is 192.168.10.1.

Attempting to ping the firewall returns "destination host unavailable". It was routing fine last night - no changes have been made to our firewall/router (which is one hop away).

I've rebooted the Windows machine to no avail.

Here's some information about the Windows server:

  • It can ping itself
  • The NIC looks fine in device manager
  • Link light and activity light are active on NIC
  • Ethernet connection in Network Properties shows status as Connected.
  • Swapped ethernet cable to no avail

Here's what isn't working:

  • Connectivity from the server to other hosts (including the same subnet).

There's no suggestion of the cause in the error logs (there are reports of failed services that depend on connectivity such as the time server)

windows-server-2003 networking

3 Answers

  1. Perhaps a dumb question - but have you tried a shut down and startup. Actual power the server down and then starting it up again? What do the system logs show?

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  2. My solution was to reinstall TCP/IP. Apparently the TCP/IP stack was in some way corrupted.

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  3. Best Answer

    Has it got the DNS server installed and did it happen after a reboot?

    If not ignore the rest of this, but if so note that there is a bug in W2k3 that the DNS server can grab port 4500. This stops the IPSEC service runing and blocks all network access to and from the server. The immediate fix is to restart DNS then restart the IPSEC service (or of course restart the server). A longer term solution is to add 4500 to the reserved ports in the TCP/IP service parameters.

    JR

    Re the DNS problem:

    See http://support.microsoft.com/kb/956189

    This refers to SBS, but it applies to standard W2k3 as well. I have been bitten by this several times and the fix described in the KB article works. I now routinely do this on all W2k3 installations.

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