Performing a loopback test on an Ethernet interface

If an Ethernet interface does not work correctly, you can perform a loopback test on it to identify the problem. An Ethernet interface in a loopback test does not forward data traffic.

Loopback tests include the following types:

Configuration restrictions and guidelines

When you perform a loopback test on an Ethernet interface, follow these restrictions and guidelines:

Configuration procedure

To perform a loopback test on an Ethernet interface:

Step

Command

Remarks

1. Enter system view.

system-view

N/A

2. Enter Ethernet interface view.

interface interface-type interface-number

N/A

3. Perform a loopback test.

loopback { external | internal }

By default, no loopback test is performed.

The external keyword is not supported in the current version, and it is reserved for future support.