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New Member

Back to back problem

I have connected two 1751's back to back using T1 crossover cable.

WIC - csu/dsu T1 on both.

And have used Frame Relay Sub-interface config with one of them using internal clock on t1.

problem: Serial up, line protocol down.

issuing sh frame-relay pc i see pvs status deleted ..

Any suggestions ??

New Member

Re: Back to back problem

I could be wrong but you may want to try issuing the following command on one of your PHYSICAL interfaces(the syntax may not be correct):

frame-relay intf-type dce

I've only done back to back Frame Relay on non-WIC platforms so I could be wrong.

New Member

Re: Back to back problem

Have you enabled frame-relay switching on one of the routers?

Becasue in back to back scenarios, since you are not using the frame-relay switch, one of the routers should be specified as the frame-relay switching by giving frame-relay switching global configuration command.

Also the frame-relay dlci numbers should be the same when you are connected back to back. So please check weather you have the same dlci on both rotuers.



Re: Back to back problem

Using frame relay with two routers you are only going to get layer2 communication, frame relay lmi between those two routers. However, if one router has 3 interfaces you could make it the frame switch on two ports, connect one to the other router and the other to the third port on the router that is also the switch. Now you can set up route maps between the port on the switch router that is not switched and the external router.

Otherwise you need three routers do simulate frame relay.

You can use your back to back connection by turning off frame relay.

New Member

Re: Back to back problem

hi all,

Thanks for inputs.It worked by enabling fr switching and making clock providing interface ad dce.

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