What are the meanings of the current state and Line protocol current state fields displayed in the command output when checking the interface status on a switch

0

You can run the display interface command to view the running status and statistics about an interface.

display interface gigabitethernet 0/0/1
GigabitEthernet 0/0/1 current state : UP
Line protocol current state : UP
The meanings and differences between the current state field and Line protocol current state field in the command output are as follows:
-The current state field indicates the physical status of the interface and is not related to Layer 3 services and protocols.
-The Line protocol current state field indicates the link protocol status of the interface and is related to protocols.
-For Layer 2 interface: Generally, if the physical status current state displays Up, the protocol status Line protocol current state displays Up.
-For Layer 3 interfaces: Only when the physical status current state displays Up and the protocol negotiation succeeds, the protocol status Line protocol current state displays Up.

Other related questions:
What it means when the state of the FR link protocol is Up
It means that the negotiation of the Local Management Interface (LMI) protocol is successful. You can run the display fr interface command to check the FR protocol information about the interface.

What should I do when a CE series switch license file changes to the trial state
If a license in trial state expires, successfully delivered configurations of a licensed feature will be retained and take effect. You are allowed to delete existing service configurations related to the licensed feature, but not to add new configurations. Therefore, apply for a new license and activate it before the current license expires. Otherwise, services will be affected.

The physical state of a serial interface is Up but the protocol state of the interface is Down
For the problem that the physical state of a serial interface is Up but the protocol state of the interface is Down, see the troubleshooting guide. For details, access the URL in the right column.

The PPPoE physical interface is Up but the state of the protocol is Down
After a PPPoE dialup, all services are born on the Dialer interface, with corresponding physical interface being Up and protocol being Down, which is normal and does not affect the services and use. Ignore it. A virtual interface is needed for PPPoE dialup to bear all services. Pay attention to the Dialer interface, and the protocol status does not need to be concerned with.

If you have more questions, you can seek help from following ways:
To iKnow To Live Chat
Scroll to top