9 Tips to diagnose remote GNU/Linux server network connectivity issues
Many new admin or Linux users get frustrated when their remote Linux box is not accessible dues to network connectivity. In this article I will try to provide tools and information about how to diagnose network configurations. You can try these tips/tools to diagnose an issue of Linux network connectivity to remote or local servers.
Steps to diagnose the problem:
#1: Use ping command
Always ping the IP address of server and then try hostname. For example:
$ ping 220.127.116.11
$ ping cyberciti.biz
#2: Use traceroute command
If you cannot ping your server at all, use traceroute to trace network problem.
#3: Look for default route / gateway IP