You can use these tools to check basic network functions.
For example, you can check the status of interfaces, routes, and connections,
and you can determine whether the IP packets are reaching their destination.
Netstat
Netstat is a tool for managing and monitoring your server. It is useful for troubleshooting TCP/IP problems.
Ping
You can use the Packet Internet Groper (Ping) function to test IP-level connectivity between two TCP/IP-capable interfaces or systems.
Trace route The trace route function allows you to trace
the route of IP packets to a user-specified destination system so you can
locate the connectivity problem.