Troubleshooting Name Resolution

Security Firewall or other security software or hardware might be blocking the connection or proxy settings might be misconfigured Name Resolution if a service such as a Domain Name Server (DNS) is not working you will be able to connect to servers by IP address but not by name Application/OS The software underpinning the service might have failed. If the Operating System (OS) has failed, there might not be any soft of connectivity to the host server.

nslookup command

IF you identify or suspect a problem with name resolution, you can troubleshoot Domain Name Server (DNS) issues with the nslookup command, either interactively or from the command prompt using nslookup -Option Host Server