Frame Relay over Back-to-Back Serial

Answered Question
Feb 28th, 2009

I have two routers (2610XM and 2621XM) connected to each other via V.35 DCE/DTE, and I'm trying to configure a Frame Relay connection over this (along with two other routers, but first things first). However, I can't keep the link up. The DCE end is configured with a clock rate of 128000, but the DTE end only says "DTE V.35 TX and RX clocks detected." The interfaces on both ends are up/down; the subinterfaces (on which the DLCIs and IPs are configured) are down/down on both ends. Neither router has its directly connected subnet in its routing table.

I can bounce the interface on either end, and the link comes up for a few seconds, during which time both routers recognize the directly connected subnet that connects them. However, the DTE end still has only the TX/RX clocks detected message. And the link goes back down after a few seconds.

During the time the link is up, also, no LMI messages appear to be getting received on either end even though plenty are being sent. Two obvious things of keepalives and frame relay encapsulation are configured on the interfaces of both ends.

Does the clocks detected message mean that I have a good back-to-back cable setup? If not, how do I finish that setup?

If the cable setup is good, at what else should I be looking in order to get the link to stay up so I can work the Frame Relay config?

Thanks for your help.

Eric Hines

I have this problem too.
0 votes
Correct Answer by Paolo Bevilacqua about 7 years 7 months ago

frame-relay switching

interface serial x/y

frame-relay intf-type dce

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Overall Rating: 5 (1 ratings)


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