Hello everyone.

Just wanted to ask if this is a behavior that has been seen here before.

When I change the metric of an interface in OSPF, it actually tears down the neighborship and re-establishes it. I noticed on my Cisco that it consistently bounces when I change the metric. It comes back very fast but.....yeah....

This a known behavior?

Yea I think that's expected. A change in most OSPF settings usually causes a bounce.

Did some more investigation and....this is very different behavior.

Did this on a Cisco, on a Juniper, and on a Mikrotik.

Change on Cisco or Juniper does *NOT* cause the adjacency to bounce. A change on Mikrotik <> Cisco does though, even if I am making the change on the Mikrotik side. So in theory, a change on the 'tik side should not elicit a neighborship teardown on the Cisco. However it does indeed go away, with all possible routing across that interface to go down. Mikrotik <> Mikrotik does not seem to have this problem.

This is highly problematic though as it does not follow standard behavior that Cisco and Juniper do when changing metrics. Not just Cisco and Juniper either, but Brocade and Force10 don't seem to do this as well.

I will do more testing and this time with traffic. I want to see if this causes packet loss. If it does then this is *very* bad. Metric changes should not cause adjacency bounces.

Here we go, it seems this has been brought up before:

viewtopic.php?t=95442

Has 'tik responded to this?