Cisco IOS Cookbook, 2nd Edition

Viewing Interface Status

Problem

You want to look at the status of your router’s interfaces.

Solution

You can look at the current status of any interface using the show interfaces EXEC command. With no arguments, this command shows the status of all interfaces on the router:

Router1#show interfaces

You can also look at a particular interface by including its name with the command:

Router1#show interfaces FastEthernet0/1

It is also often useful to look specifically at the IP configuration of one or all of your interfaces by using the show ip interface command:

Router1#show ip interface brief
Router1#show ip interface FastEthernet0/1

Discussion

There is a huge amount of information in the output of the show interfaces command, and the actual content varies from one interface type to another:

Router1#show interfaces FastEthernet0/1 FastEthernet0/1 is up, line protocol is up Hardware is AmdFE, address is 0001.9670.b781 (bia 0001.9670.b781) Internet address is 172.22.1.3/24 MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation ARPA, loopback not set Keepalive set (10 sec) Full-duplex, 100Mb/s, 100BaseTX/FX ARP type: ARPA, ARP Timeout 04:00:00 Last input 00:00:04, output 00:00:00, output hang never Last clearing of "show interface" counters never Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0 Queueing strategy: fifo Output queue: 0/40 (size/max) 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 1000 bits/sec, ...