Sham link down when router reloads

[Artem Voskresenskiy]

Hello.

I can configure  SHAM links between me3600-24fs and they are up and fine . However, when I reboot me3600 the , after reboot  that SHAM's are down. The only way I can get them to come back up is to  remove the SHAM statements from rebooted me3600 and then readd them.

?

Thanks.

[kriska.martin]

I was facing the same problem today when playing with SHAM-LINKs

a soultion/workaround seems to be  to allow Sham-link endpoints to be redistributed into OSPF on PE routers

on PE routers themself the sham-link endpoint is reachable via BGP route and no sham-link flapping is occuring.

EXPLANATION:

IOS tries to bring the sham-link up when:

1. It's configured and we check if we have a BGP route for the other end point

OR

2. When we receive the bgp route for the other endpoint and we want to redistribute it. Instead of redistributing the sham-link goes up.  That's a way OSPF get the notification that the BGP route has arrived

it makes sense since after reload the sham-links is present in startup configuration but BGP convergence takes some time

source:

http://www.routerie.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=96;t=000005