02-03-2010 09:37 PM - edited 03-06-2019 09:34 AM
Hi friends,
When I did port spanning on 6500(gig port RJ45 WAN uplink) switch CPU utilization went up to 55% and caused huge packet drops which I think unusual or is it a normal behavior?
Spanned out put (not even 1 minute) was huge even wire shark could not afford it.
Thanks
02-04-2010 12:00 AM
Hi friends,
When I did port spanning on 6500(gig port RJ45 WAN uplink) switch CPU utilization went up to 55% and caused huge packet drops which I think unusual or is it a normal behavior?
Spanned out put (not even 1 minute) was huge even wire shark could not afford it.
Thanks
Hi,
The architecture of Catalyst 6000/6500 Series Switches, SPAN sessions do not affect the performance of the switch, but, if the SPAN session includes a high traffic / uplink port or an EtherChannel, it can increase the load on the processor. If it then singles out a specific VLAN, it increases the workload even more. If there is bad traffic on the link, that can further increase the workload.
Check out the below link for more information.
http://www.cisco.com/en/US/products/hw/switches/ps708/products_tech_note09186a00804916e0.shtml#span
If helpful do rate the post
Ganesh.H
02-04-2010 01:33 AM
hi,
thanks,
it might be due to bad traffic. actually i found unknown traffic (20mb) on my wan link
to check this traffic only i enabled SPAN and there was no logg for this .I realized it only when I saw the packet drops
I am trying to find what traffic is the origin of traffic ..
thanks
02-04-2010 09:10 AM
Hi Shiju
Try to restrict the source packets as much as possible.. If you are trying to troubleshoot issues, and want to configure port mirroring for that, you can probably configure an access-list and associate it with your monitor session command, to narrow the traffic you are monitoring... if you are spanning for IPS/IDS functionality, then you might have to monitor the whole traffic...
Switch(config)# monitor session 1 filter ip access-group 100
Also try to isolate bad traffic.. you have a traffic type option on the monitor session command. you can select good on that option...
Hope this helps.. all the best
Raj
02-06-2010 11:39 PM
thanks for mail,
I was working with cisco TAC also on this case as per them i am hiitng the bug CSCsi74194 my present ios is 12.2(18)SXF6. they reccommend 12.2(18)SXF17 .
thanks
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