Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
Community Member

preventing broadcast storm without stp?

is it possible to control the broadcast storm (caused by loop) with "storm-control" command without enabling STP?

6 REPLIES
Super Bronze

Re: preventing broadcast storm without stp?

Nope - you need to stop the loop... by removing the loop, or allowing STP to do it for you.

Storm control might limit the effect, but why you would ever want a loop in the network is difficult to imagine..

Aaron Please remember to rate helpful posts to identify useful responses, and mark 'Answered' if appropriate!
Purple

Re: preventing broadcast storm without stp?

Yes, you do not need STP to enable this feature.

Note that loops are not the only thing that will cause broadcast storm.. malfunctioning NICs have been known to do that as well....

Even if you are running STP, it's useful to run this feature..

Hope that helps - pls rate the post if it does.

Regards,

Paresh

Community Member

Re: preventing broadcast storm without stp?

STP is a good thing, Rapid STP is even better...I'm still trying to figure out what reason you would have for wanting disabling it?

Community Member

Re: preventing broadcast storm without stp?

its not something I want to have. But there are some unmanaged switches around connected to backbone switch and they do not support STP. I supposed it might be a good idea to execute 'storm control' command until we replace those dummy switches with catalyst rstp supported ones.

Purple

Re: preventing broadcast storm without stp?

Howdy,

As I mentioned in my earlier post, storm control is useful even if STP is enabled...

Hope that helps - pls rate the post if it does.

Regards,

Paresh

Re: preventing broadcast storm without stp?

I'm not sure if this is really what you meant, but if you want to configure your network with a physical loop and disable spanning tree, storm control is not going to help. Your network will just be unusable.

If you have a sustained loop in your network, any packet will potentially use all the bandwidth available on this loop. Not only broadcasts, multicasts but also unknown unicasts. Your storm control will need to be configured for any type of traffic and will continuously kick in.

You'd rather have no redundancy in your network then.

Also, if you expected storm control to have any kind of effect in your topology, it means that you have at least one bridge supporting this feature on your physical loop. If this bridge support storm control, it probably also support some version of STP;-) It will then be able to run STP through the dumb switches and prevent the loop (if the switches are dumb, I hope they are dumb enough to let BPDUs go through). It's not an ideal solution, there are some drawbacks, but it's definitely more viable than a permanent loop in the network.

Regards,

Francois

603
Views
5
Helpful
6
Replies
CreatePlease to create content