We've been getting the following error a couple of times a day:
A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: TCP Provider, error: 0 - The requested name is valid, but no data of the requested type was found.).
In doing some research, it seems like this is an error resolving the host name to an IP address. What confuses me is that the issue doesn't happen every time. Has anyone seen this issue before? Thanks in advance.
Best Answer
When I had a similar intermittent problems I found that I had a DNS Search Suffix list with some expired domains in it that caused the DNS lookup to run for over 30 seconds. Since the the server caches the DNS names for approx 20 minutes I could not reproduce the issue with ping since the cached DNS entry is used.
Check your search suffix list with "IPCONFIG /ALL", try to reproduce the problem with a cleared DNS cache "IPCONFIG /FLUSHDNS"