Command Reference Guide

3Com Router 5000 Family and Router 6000 Family loopback (CT3 Interface) ● 251
Command Reference
loopback (CT3 Interface)
Purpose Use the loopback command to configure the loopback mode of the CT3 interface.
Use the undo loopback command to disable the CT3 interface to perform
loopback.
Syntax loopback { local | payload | remote }
undo loopback
Parameters local
Enables the CT3 interface to perform local loopback.
payload
Places the CT3 interface in an external payload loop.
Data passes the framer in this case and is looped back
after payload is generated.
remote
Enables the CT3 interface to perform remote
loopback. Data does not go through the framer in this
case and will be looped back before the payload has
been generated.
Default By default, loopback is disabled on the CT3 interface.
Example Enable the interface T3 1/0/0 to perform local loopback.
[3Com -T3 1/0/0] loopback local
View This command can be used in the following views:
■ CT3 Interface view
Description Loopback is usually used for some special tests. Disable it in normal cases.
If you place a CT3 interface encapsulated with PPP in a loopback, it is normal that the
state of the link layer protocol is reported down.