How to limit broadcast traffic on a 3560 switchport ?

[jesper_fr]

Hi all,

How do I limit broadcast/mulitcast traffic on a switchport to e.g. 5000 pps ? I don't want the port to shut down, just block or drop broadcast traffic that exceeds 5000 pps   

Best regards,

Jesper

[cadet alain]

Hi,

I just found this: http://blog.ipexpert.com/2010/03/15/old-ccie-myths-storm-control/

So maybe you are not blocking one type of traffic which is responsible for the ISP shutting down the link.

Could you test with only multicast  or only broadcast and tell us what it does.

Regards.

Alain

Don't forget to rate helpful posts.

[jesper_fr]

Hi Alain,

I know what kind of traffic that causes this multicast storm. It's LLC traffic caused by a spanning-tree fault in the network.

I have attached a wiresahark trace that shows the LLC multicast storm. The trace taken with an older wireshark version (1.2)  as the new version crashed all the time.

Regards,

Jesper

[cadet alain]

Hi,

sorry my windows clipboard had fun with me 

http://www.cisco.com/en/US/docs/switches/lan/catalyst3560/software/release/12.2_52_se/configuration/guide/swtrafc.html#wp1085982

Regards.

Alain

Don't forget to rate helpful posts.

[Alessio Andreoli]

Sent from Cisco Technical Support iPad App

[daniel.rodrig]

Just one thing.

Remember that at L2 all broadcast traffic is a multicast, but not the other way around (all multicast traffis is not a broadcast). When using storm control you should have this in mind.

You should set your multicast level higher than your broadcast.

Also keep in mind, that storm control does not differentiate traffic clases, and you may be dropping traffic that may be critical for you (and for the sanity of your network).

Daniel

Network Faculty