Users Guide

If the rate of control packets towards the CPU is higher than it can handle, CoPP provides a method to selectively drops some of the
control trac so the CPU can process high-priority control trac. You can use CoPP to rate-limit trac through each CPU port queue of
the NPU.
CoPP applies policy actions on all control-plane trac. The control-plane class map does not use any match criteria. To enforce rate-limiting
or rate policing on control-plane trac, create policy maps. You can use the control-plane command to attach the CoPP service
policies directly to the control-plane.
The default rate limits apply to 12 CPU queues and the protocols mapped to each CPU queue. The control packet type to CPU ports
control queue assignment is xed. The only way you can limit the trac towards the CPU is choose a low priority queue, and apply rate-
limits on that queue to nd a high rate of control trac owing through that queue.
See show control-plane info for specic information on protocols and rate limits of CPU queues.
Congure control-plane policing
Rate-limiting the protocol CPU queues requires conguring control-plane type QoS policies.
• Create QoS policies (class maps and policy maps) for the desired CPU-bound queue.
• Associate the QoS policy with a particular rate-limit.
• Assign the QoS service policy to control plane queues.
By default, the peak information rate (pir) and committed information rate (cir) values are in packets per second (pps) for control plane.
CoPP for CPU queues converts the input rate from kilobits per second (kbps) to packets per second (pps), assuming 64 bytes is the
average packet size, and applies that rate to the corresponding queue – 1 kbps is roughly equivalent to 2 pps.
1 Create a class-map of type control-plane and congure a name for the class-map in CONFIGURATION mode.
class-map type control-plane class-map-name
2 Return to CONFIGURATION mode.
exit
3 Create an input policy-map to assign the QoS policy to the desired service queues in CONFIGURATION mode.
policy-map type control-plane policy-map-name
4 Associate a policy-map with a class-map in POLICY-MAP mode.
class class-name
5 Congure marking for a specic queue number in POLICY-MAP-CLASS-MAP mode (0 to 11).
set qos-group queue-number
6 Congure rate policing on incoming trac in POLICY-MAP-CLASS-MAP mode.
police {cir committed-rate | pir peak-rate}
• cir committed-rate—Enter a committed rate value in pps (0 to 4000000).
• pir peak rate — Enter a peak-rate value in pps (0 to 40000000).
Create QoS policy for CoPP
OS10(config)# class-map type control-plane copp
OS10(conf-cmap-control-plane)# exit
OS10(config)# policy-map type control-plane copp1
OS10(conf-pmap-control-plane)# class copp
OS10(conf-pmap-c)# set qos-group 2
OS10(conf-pmap-c)# police cir 100 pir 100
View policy-map
OS10(conf-pmap-c)# do show policy-map
Service-policy(control-plane) input: copp1
Class-map (control-plane): copp
Quality of service
455