Command Reference Guide

3Com Router 5000 Family and Router 6000 Family t1 set loopback ● 321
Command Reference
t1 set loopback
Purpose Use the t1 set loopback command to set the loopback mode of a T1 line on the
T3 interface.
Use the undo t1 set loopback command to disable the T1 line to loop back.
Syntax t1 line-number set loopback { local | remote | payload }
undo t1 line-number set loopback
Parameters line-number
T1 line number. Valid values are 1 to 28.
local
Enables the T1 line to perform local loopback.
remote
Enables the T1 line to perform remote loopback.
payload
Enables the T1 line to perform far-end payload
loopback.
Default By default, T1 lines are disabled to loop back.
Example Set the loopback mode on the first T1 line on the T3 interface to local.
[3Com -T3 1/0/0] t1 1 set loopback local
View This command can be used in the following views:
■ CT3 Interface view
Description If a T1 line encapsulated with PPP is placed in a loopback, it is normal that the state of
the link layer protocol is reported down.
Loopback is usually used for some special tests. Disable it in normal cases.