Scenario: I have a Centos 6.x VM which gets an IP address via DHCP. I could not get any external access so I wanted to start troubleshooting. The first step was making sure I had the correct gateway and could ping it.

 route -n

This should display

The IP address highlighted in red is the gateway. The green U flag indicates its UP and G indicates it is the gateway.

Note: from the man page the (route) -n flag means:

“show numerical addresses instead of trying to determine symbolic host names. This is useful if you are trying to determine why the
route to your nameserver has vanished”