Friday, May 30, 2008

Troubleshooting OSPF over Frame-Relay Part 1

Full mesh of PVCs between 3 routers: R4 R5 and R6
Frame-relay map statements DO NOT have broadcast statement
Adjacencies do not form.

This is from debug ip packet on R6:

R6#debug ip packet
IP packet debugging is on
*Mar 1 01:00:26.367: IP: s= (local), d= (Serial1/1), len 76, sending broad/multicast
*Mar 1 01:00:26.371: IP: s= (local), d= (Serial1/1), len 76, encapsulation failed

After enabling broadcast on the frame maps, adjacencies came up

Point-to-multipoint ospf networks need broadcast keyword on frame-relay map.
Without it you will see "encapsulation failed" when the router tries to send multicast hellos.


  1. I would like to add that if inverse arp were enabled then broadcast would be mapped by default. In the example above, inverse arp was disabled.

  2. I am really having a hard time with OSPF and Frame relay. Thanks for sharing this solution. It helps me a lot. Encapsulation didn't failed.
    Thank you so much!

    Jo-An from collier d'ambre pour bébé 


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