ERS 8600 cpu usage going to 40% and going down

[mats84]

Hi All

I have a 8600 installed with more than 80 edge switches.The issue is the CPU usage on the Core 8600 is going up till 40% - 50% and goes down to normal on a frequent basis.When the CPU usage is going high the ping time to the gateway CORE VLAN ip is going to 1500-2000 ms for 1 or 2 pings and comes back again to 1ms continuously.It never used to go high like on a frequent basis before.

Its not affecting the working of network devices but then is this normal to happen on a frequent basis like every 15 or 20 min interval.

Need help guys.

Thanks & Regards

Mathews

 

[HungryHouse]

Which SF do you have and what version of code are you running on the 8600?


Real trouble call:
Customer: "I have a huge problem. A friend has put a screensaver on my computer, but every time I move the mouse, it disappears!"

 

[andy88]

The cpu ramping up is not always an issue

Is there anything in the logs that correspond with the high cpu? things like stp or routing convergence can cause high cpu. Or ports bouncing.

Check your arp timers the switch sometimes re-arps all entries in its cache which will cause high cpu.

If you have a large number of vrrp instances may be adding load

You could run a trace 9 3. This will log all packets hitting the cpu, look to see if you are seeing unwanted traffic. Only do this if you understand how it works and the risks. Don't run it for too long.

Move a sniffer around the vlans and see if you see a high level of broadcast traffic as this will hit the cpu.