DTE Loop on a 1841

[Shaun.proctor]

I am currently trying to loop a Serial0/1/0 interface on to itself. On the 1721 I would just use the loop DTE command under the interface and be able to see the loop, however in a 1841 I am unable to loop the interface using this method. I am wondering if anyone else has seen this, and if there is another way to configure the loop.

[#2]

To enable a software loop back the "loopback dte". This command is used to test the performance of the integrated CSU/DSU. Packets are looped from within the CSU/DSU back to the serial interface of the router.

[Shaun.proctor]

When I do this command I am still seeing the interface down/down. When I did it in a 1700 router I always saw the interface up/up looped and was able to run to it. I have tried that command a more than 1 1841 with no luck. Is anyone else seeing this problem?