Name Resolution In Connection String Fails From Network Share

I need to go sit together with the network infrastructure guys to see why suddenly SQL connection errors like below occur. As a preparation, please provide input why this error c

Solution 1:

Use the IP address for now. If you really, really, really want a friendly name in the connection string, then use the hosts file if your network folks can't get the name resolution working. When the server moves, you can either update the config file to point to the new server (by name, if they figure out how to get it working by then, or by new IP if not), or update the hosts file to map the old friendly name to the new IP address.

We can't really tell you why it changed or why it is broken - you should get a better answer from your network team once you provide them evidence such as being able to telnet to the machine on port 48000 by IP address but not by name. They might not know the fix but that specific case is probably better asked on ServerFault.