Giuseppe Larosa Tue, 02/10/2009 - 12:25

Hello Johann,

look at CoPP = control plane policing


however even a single SNMP get can be disruptive if every few minutes the whole BGP table is asked to the device and the device is handling a BGP full table.

so also what SNMP gets are done and the polling rate make the difference.

Hope to help


Johann Frey Tue, 02/10/2009 - 13:18

hello giuseppe,

thx for the link, but CoPP is clear for me.

my question is, is there a default rate limiter? which block my snmp request after x snmp request per sec?

Thanks - Cheers


Giuseppe Larosa Tue, 02/10/2009 - 13:40

Hello Johann,

I don't think there is a default rate-limiter for SNMP.

There are some built-in rate-limiters for the data plane to limit user traffic packets punted to main cpu:

The PFC3 and DFC3 provide hardware support for CoPP. CoPP works with the PFC3 rate limiters.

The PFC3 supports the built-in "special case" rate limiters that can be used when an ACL cannot classify particular scenarios, such as IP options cases, TTL and MTU failure cases, packets with errors, and multicast packets. When enabling the special-case rate limiters, the special-case rate limiters override the CoPP policy for packets matching the rate-limiter criteria.

Hope to help


Giuseppe Larosa Tue, 02/10/2009 - 14:05

Hello Johann,

there isn't a default rate limiter but you can implement one.

I mean I think it is a wanted feature to let the network engineer to decide what to do in the management plane.

I think TAC will answer you in this way.

Hope to help



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