Loopback on WAN Interface Debugging

You can perform loopback testing on the WAN interface for debugging purposes. Loopback debugging can be activated on any WAN interface (name or type).

To perform loopback testing, use the following CLI command:

# debug ethernet loopback interface <interface name / type>

For example:

# debug ethernet loopback interface GigabitEthernet 0/0

The no debug command disables the loopback test.