storm supression on CatOS

[Cooky]

Don't ask me why we're still running this ancient switch, but I'd like to know if it's possible to do storm supression on a Cat4k running CatOS 7.1(1).

If so what's the command, or is it only available on IOS?

 

[nightowl]

From what I am seeing, it is not supported in CatOS on the 4k.

 

[jlazzaro]

+1...

set port broadcast - this command is not supported on the Catalyst 4000 and 2948G series switches

 

[spidey07]

Originally posted by: jlazzaro
+1...

set port broadcast - this command is not supported on the Catalyst 4000 and 2948G series switches

That means it's the 4000 software that doesn't support it.

Weird, almost all of their switches have broadcast suppression.

 

[Cooky]

Thanks guys for the quick replies...at least I know what my options are...or what options I don't have.

Troubleshooting a CatOS switch is bad enough, let alone the issue is sporadic.
It comes and goes...was on phone w/ TAC for almost 4 hours, and still couldn't figure out what was causing the issue.

Crossing my fingers until we can get them upgraded to a new IOS switch...

 

[spidey07]

What's the problem? In a lot of ways trouble shooting on CatOS is better.

 

[Cooky]

In what way is troubleshooting on CatOS better than IOS?
If you want to try something to see if it works, it's applied permanently. ie. can't reboot or do reload in 5
Maybe there are other things that I don't know about...after all I'm not too familiar w/ CatOS.

The issue is the switch isn't moving traffic fast enough.
Network comes to a crawl sometimes, usually during peak hours.
CPU utilization stays at 22% the whole time.
We see some stats for txQueueBuffer so we know it's dropping packets due to performance capability but that counter hasn't incremented at all.

 

[spidey07]

run show top to see heaviest used ports

 

[Cooky]

We did; problem persisted after we shut down those ports.

 

[spidey07]

Originally posted by: Cooky
We did; problem persisted after we shut down those ports.

There's so many things that could be going on. You sure you don't have some kind of bridging loop? Try turning on bpduguard and loopguard. Do you actually get packet loss/drops?

 

[Cooky]

There hasn't been any spanning-tree convergence since we last cleared counters...although it sure did seem like a spanning-tree loop somewhere.

How the heck do you turn on bpduguard on a CatOS?
The only options we get are:
>set spantree guard ?
none Disable spantree guard
root Set spantree root guard
loop Set spantree loop guard
default Set spantree guard to default

 

[spidey07]

I'm not sure off the top of my head, it may be past the software you're running so that would be something to look into. loopguard will help. If during your problem you see a high amount of mcast/bcast traffic then some kind of bridging loop is your likely culprit. So without much more information, look at layer2 and bridging or unidirectional links (flaky fiber).

 

[jlazzaro]

> (enable) set spantree portfast ?
<mod/port> Module number and Port number(s)
bpdu-guard Portfast BPDU guard
bpdu-filter Portfast BPDU filter

 

[Cooky]

Thank you!

We usually have both loopguard & bpduguard enabled, but only on the IOS switches.