Many Linux distributions provide a number of tools to simplify network configuration and connectivity verification. The following tools work with every distribution and allow you to administer your network from the command line:
ping: Checks network connectivity
ifconfig: Displays the configuration for a network interface
traceroute: Shows the path taken to reach a host
route: Displays the routing table and/or lets you configure it
arp: Shows the address resolution table and/or lets you configure it
netstat: Displays the status of the network
