SQL Server 2008 R2 SP1 - Intermittent network issue (after applying SP1)

Question

Hi All,

We're having an issue since we applied the SP1 patch to our SQL server 2008 R2 server. We're occasionally seeing the following error:

A network related or instance-specific error occured while establishing a connection to SQL server. The server was not found or was not accessible. Our firewall is set properly and allows remote connections. The timeout is set to 15 seconds. We did not see this error message before patching, and now that we do see it, it's only occuring occasionally. You can try and establish the connection almost immediately after recieving the error, and it will connect fine. I also confirmed that the server is resolving from our DNS server fine. The SQL browser service is also running.

Does anyone have any ideas?

Thanks.

Answer 1

Hi EvolutionX,

This team supports the Open Specifications documentation. You can read about the Microsoft Open Specifications program here,http://www.microsoft.com/openspecifications/en/us/default.aspx

The library of Open Specification documents is located here, http://msdn.microsoft.com/en-us/library/dd208104(PROT.10).aspx

This forum may be a more appropriate one for your question, http://social.msdn.microsoft.com/Forums/en-US/sqlsetupandupgrade/threads

Regards,
Mark Miller
Escalation Engineer
US-CSS DSC PROTOCOL TEAM

Answer 2

I don't know if this will help, but we were having the same error on a new IBM server.

The problem appeared to be caused by having two network adapters with the second one due to be configured as a failover, but the second adapter was not connected to the network at the time.  When the second network adapter was disabled the problem went away.  Re-enabled it and the problem came back - but only AFTER a reboot!