Cisco Interface and Line Protocol Status description | what are Line Protocol status Down/UP means

Cisco interface status description | Description of Show IP int brief command status:

You can check the Cisco interfaces with command “show ip interface brief”. The interface and line protocol status output gives information related to the physical status of the interfaces, an example of output is as shown above in figure.

When an interface is operating properly, there is only one possible status output. Following are the all possible status of interfaces.

Interface status is up, line protocol is up:

This status shows that interface is OK with physically and configured protocol is also working fine.

Interface status is down, line protocol is down

This state indicates a physical interface problem. The interface may be administratively shut down, a situation that could cause both ends to go down. To bring an interface up, use the no shutdown command under the interface configuration mode.

Interface status is  up, line protocol is down

This state means that interface is physically up but there is some protocol mismatch, attributed to a clocking or framing problem.  To resolve this issue you need to check out your protocol/keepalive configurations.

 Interface status is administratively down, line protocol is down

This state indicates interface is shutdown by administrator by using no shutdown command under the interface configuration mode. To bring the interface up, use the no shutdown command under interface configuration mode.

Interface status is up, line protocol is up (looped)

This status shows that a loop exists in the network. This problem could be associated with an existing loopback interface.

Interface status is up, line protocol is down (disabled)

This state often indicates a hardware problem and may be associated with a service provider company problem.