The command show ip interface brief displays a summary of the IP address on the interface and the interface's status. The status shows whether the interface is up. This command is useful when you are connected to a router or switch with which you are not familiar, because it allows you to obtain the state of all interfaces or switch ports.

Sample output of this command is shown below:
Switch88# show ip interface brief Interface IP-Address OK? Method Status Protocol FastEthernetO/1 unassigned YES manual down down FastEthernet0/2 unassigned YES manual down down FastEthernetO/3 unassigned YES manual down down FastEthernetO/4 unassigned YES manual down down FastEthernetO/5 unassigned YES manual down down FastEthernetO/6 unassigned YES manual down down FastEthernetO/7 unassigned YES manual down down FastEthernetO/8 unassigned YES manual up up FastEthernetO/9 unassigned YES manual down down FastEthernetO/10 unassigned YES manual down down
This command does not display subnet mask information. You should use other commands, such as show ip interface or show run interface, to verify the subnet mask.

IP statistics about the interface are displayed with the command show ip interface. Adding the brief keyword tells the switch to leave out everything but the state of the interface and its IP address.

To view the routing protocol advertising an interfaces network, you would use the command show ip protocol.