Peak

[londint]

Using a show system command on our switch yielded the result - Peak - 3 %. How can I check what was happening at the time it show 3 %. I ahve gone through the show log and show log buff but nothing.

Also the temp-alarm is off, how do i go about enabling this and wht effect will it have. Also how do i get reports if it exceed the normal.

Thanks

[Prashanth Krishnappa]

I might have been a momentary broadcast which could have caused the backplane utilization to peak to 3%.

The temperature-alarm feature is always on and cannot be turned off. The field "off" in the output of sh system indicates the temperature is normal.

[londint]

Thanks. Please this may sound somehow but how do i trace this broadcast. I have CiscoWorks 2000 running here as well as Traffic Director. Is there a way i can tell which device was sending out this broadcast?

Thanks for your help.

[bsivasub]

I don't think you can say for sure it is due to broadcast. One way of checking is to look at router interface in the same broadcast domain to see if they recorded broadcast packets. But as i said, this peak could be due to general burst of traffic like backup etc... We are talking about backplane traffic with that command and hence it could be anything. hope this helps

[kimtoovey]

I have a similar issue where I was asked to confirm if the network was experiencing excessive broadcast traffic. Short of visiting each member interface of the broadcast domains I can not see a IOS command to see an aggregate of broadcasts. I was also think I could look at the Interface where the router touches the domain however I felt there might be a command that summarises the broadcasts on a control plane.

From what I can see my options are:

1) SPAN all interesting ports and analyse the traffic with a protocol analyser.

2) Look at the Interface Stats for a sample of Interfaces on the interesting VLAN.

3) Look at the Interface on the Router connected to the interesting VLAN and get an aggregate of the received broadcasts for whole VLAN.

What have other been doing to answer this question?