line protocol is down (looped)

[Krelian]

Hi guys,

We just got a T1 circuit installed, and attempting to configure a Cisco 2600 to get connectivity. What we got after the configuration of the serial interface is "Serial 0/1 is up, Protocol is down (looped)". I am certained that non of the interfaces are setup as loopback. So what does this mean? Could it be the telecomm provider who has put a loopback on their end? The circuit is setup with Frame-relay IETF encapsulation with ANSI LMI.

Any help is appreciated.

 

[wybnormal]

Someone at telco forgot to clear a loop test.. get on the horn with your provider and have them clear the line. On the off chance it might be your end, try reseting the CSU/DSU.. I have seen once in a great while the DSU go stupid like this.. not often but it does happen.

MikeS
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http://www.packetattack.com

"The trouble with giving up civil rights is that you never get them back"

 

[svermill]

If you have a smartjack in the picture that is a very likely suspect. They are in loopback by default so as to keep alarms from going off at telco when the circuit isn't provisioned/hooked up.

 

[jeter]

Is this a frame relay circuit? If so like the others have mentioned the circuit is in a test mode ( NNI mode ) the providers ANS group ( Advance network Services ) can remove the loop on the frame relay side if the loop is local they mey need to dispatch to remove the loop in the DAX.

What type of NIU ( circuit connection ) at your prem did telco provide. If it had a 9pin connection on the card you can hook up via hyperterminal at 9600 N 8 1 and check out the setting alarms and loops. Good Luck!!! Jeter@LasVegas.com
Fisher CCNA
Sprint-Data

 

[kreggo]

Quickest check is to pull the cable between your DSU and the telco smart jack. If you still see a loopback on the router port, it's not telco.