If you are experiencing name resolution problems on a network that uses a name server, it is a good idea to ping the name server to make sure it is online.
If the name server is beyond the local subnet, ping the gateway to ensure that name resolution requests can reach the name server.
Double-check the name you entered to ensure that it is the correct name for the resource. If none of these measures lead you to a solution, you can use the nslookup utility to query the name server about specific entries.