'WIndows 2008 R1 suffers recurring 'Error 81' when running diagnostics. Unable to connect to DC

I've a recurring issue on a number of 2008 R1 servers. Replication stops completely, and any attempt to run any AD-related snap-ins or diagnostics fail.

For example:

C:\Windows\system32>dcdiag

Directory Server Diagnosis

Performing initial setup:
   Trying to find home server...
   Home Server = MYDC
   Ldap search capabality attribute search failed on server MYDC, return
   value = 81

Other tools also fail in the same manner:

C:\Windows\system32>repadmin /showreps
[d:\rtm\ds\ds\src\util\repadmin\repbind.c, 444] LDAP error 81 (Server Down) Win32 Err 58.

LDP can't connect to the server either:

ld = ldap_open("mydc", 389);
Error <0x51>: Fail to connect to mydc.

There are a couple of event log entries, but frankly I'm not sure if they are a cause or a symptom.

Event 1311: The Knowledge Consistency Checker (KCC) has detected problems with the following directory partition. 

Directory partition:
CN=Configuration,DC=ad,DC=mydomain,DC=co,DC=uk

Event 1566: All directory servers in the following site that can replicate the directory partition over this transport are currently unavailable. 

Site:
CN=MYSITE,CN=Sites,CN=Configuration,DC=ad,DC=mydomain,DC=co,DC=uk 
Directory partition:
DC=ad,DC=mydomain,DC=co,DC=uk 
Transport:
CN=IP,CN=Inter-Site Transports,CN=Sites,CN=Configuration,DC=ad,DC=mydomain,DC=co,DC=uk

A reboot always clears this up, and always after a month or two the same problem will crop up again on a different server. I've seen it on 5 different servers in different domains so far. Reboots are fine, but it always feels like a bit of a blunt instrument. I was hoping someone might have come across this before and be able to offer a fix.

thanks...

windows-server-2008


Solution 1:[1]

Is this related to: "All the TCP/IP ports that are in a TIME_WAIT status are not closed after 497 days from system startup in Windows Vista, in Windows 7, in Windows Server 2008 and in Windows Server 2008 R2" http://support.microsoft.com/kb/2553549

Sources

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Source: Stack Overflow

Solution Source
Solution 1 dmah

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