Switch CPU usage and Collisions

[soapyfish]

Hi,

Does anyone know how much CPU utilization on a switch is too much ?

 

I am looking into this as I am using Nagios3 to monitor my switching via snmp and well I am not sure how much of a load it should be warning me about.

 

Thanks

[notlob]

Hi,

Does anyone know how much CPU utilization on a switch is too much ?

 

I am looking into this as I am using Nagios3 to monitor my switching via snmp and well I am not sure how much of a load it should be warning me about.

 

Thanks

 

Hope this late reply might still be useful.

 

If it was me I'd look to establish a couple of baseline figures: one for when the switch is idle and one for when your network is at its busiest but still working fine.

 

The "idle" baseline should give a low CPU utilisation figure for most switches from what I've seen. However it could still be useful to pick up on network problems at normally quiet times.

 

The "busy" baseline might be more useful to set a warning level. Picking some numbers out of the air, let's say the switch runs at 50% utilisation at the busiest time of day. You could then set a warning level a little higher than this (say 55% or 60%?) which would trip if there is a broadcast storm or other issue. If you get a lot of warnings then you can always fine-tune the level.

[EduAussie]

Hi,

Does anyone know how much CPU utilization on a switch is too much ?

 

I am looking into this as I am using Nagios3 to monitor my switching via snmp and well I am not sure how much of a load it should be warning me about.

 

Thanks

 

It depends on the make/model of switch. Typically, the CPU utilisation should be low (well under 50%).

[SYNACK]

You want a chunk of overhead to make sure that it can cope with random bursts and future proofing, if your switch is routinely going above about 60% then you should be starting to plan for buying a bigger/faster one or structuring your network differently to lower the load on the switch in question.

[CyberNerd]

I agree on the 60% figure - how many devices/VLAN's do you have?

Have you used wireshark to analyse some of the data?