Passport 8600 Gig port shuts down with excess control frames

[stuartcoe]

Passport 8600 Gigbit ethernet port with Baystack BPS/450 stack connected. Port became disabled and the following message appeared in the log:
[03/31/03 08:42:02] Link Down 3/5.Port is a trunk port
[03/31/03 08:42:02] Link Down(3/5)
[03/31/03 08:42:02] WARNING Task=tMainTask Shutdown port 3/5 due to
excessive control frames multicast 28253, broadcast 0 packet per second

Any ideas on what might cause this (multi-cast storm perhaps?) and how to stop the port from shutting down?

 

[ZachBenj]

We are using code 3.3 on our 8600 and have SMLT to several 450 stacks. In order for it to work we had to turn down the rate limit on each port that participated in the MLT on the 8600s. We set it to 3000. Try turning down the rate limit on each port that participates in the MLT. It is under edit for each port. Do it for both Multicast and broadcast.

My suggestions are what I would try myself. If incorrect, I welcome corrections to my knowledge.
Scott
stomlin@baptistfirst.org

 

[raceman3]

Under the port configuration you can modify the cp-limit parameter to prevent this from happening. I've seen this issue several times any usualy what causes it is a stg loop. The 8600 goes into survival mode and shuts the port down to prevent the rest of the box from being affected

 

[Ewey]

Stuey, I've seen this problem caused by:-

Simultaneous Ghosting of multiple work stations, config error and physical loop back -self inflicted, testing a port.
The best bet is to put a threshold on, we use the maximum configurable value, and just to be anal, set a corresponding threshold to notify the Networks Manager that the threshold has been hit.
Cheers,
Ewey.