Administrator Guide

Table Of Contents
1. Create a QoS input policy for the router and assign the policing.
CONFIGURATION mode
qos-policy-input name cpu-qos
2. Create an input policy-map to assign the QoS policy to the desired service queues.l.
CONFIGURATION mode
policy-map--input name
cpu-qos service-queue queue-number qos-policy name
3. Enter Control Plane mode.
CONFIGURATION mode
control-plane-cpuqos
4. Assign a CPU queue-based service policy on the control plane in cpu-qos mode. Enabling this command sets the queue rates
according to those configured.
CONTROL-PLANE mode
service-policy rate-limit-cpu-queues input-policy-map
The following example shows creating the QoS policy.
DellEMC#conf
DellEMC(conf)#qos-policy-input cpuq_1
DellEMC(conf-qos-policy-in)#rate-police 3000 40 peak 500 40
DellEMC(conf-qos-policy-in)#exit
DellEMC(conf)#qos-policy-input cpuq_2
DellEMC(conf-qos-policy-in)#rate-police 5000 80 peak 600 50
DellEMC(conf-qos-policy-in)#exit
The following example shows assigning the QoS policy to the queues.
DellEMC(conf)#policy-map-input cpuq_rate_policy cpu-qos
DellEMC(conf-qos-policy-in)#service-queue 5 qos-policy cpuq_1
DellEMC(conf-qos-policy-in)#service-queue 6 qos-policy cpuq_2
DellEMC(conf-qos-policy-in)#service-queue 7 qos-policy cpuq_1
The following example shows creating the control plane service policy.
DellEMC#conf
DellEMC(conf)#control-plane
DellEMC(conf-control-plane)#service-policy rate-limit-cpu-queues cpuq_rate_policy
Protocol to CPU Queue Mapping
CoPP enables you to rate-limit control-plane packets that are destined to the CPU there by, preventing undesired or malicious
traffic from entering the CPU queues. You can rate-limit CPU bound traffic both on a per protocol as well as per queue basis.
When packets ingress through any of the front-end ports, the system identifies the packets that are CPU bound based on the
protocol configurations. Packets bound to the CPU are also identified based on the packet-type such as ttl0, ttl1, and so on.
These packets are then re-directed to the CPU on predefined CPU queues. This type of Control traffic re-direction is achieved
using ACLs or through the protocol-to-queue table that is maintained in BCM.
The following table shows the default protocol to CPU queue mapping:
Table 15. Protocol to CPU Queue Mapping
CPU
Que
ue
Wei
ght
CPU Queue
Rate Shape
(PPS Rate)
Protocol
0 1 600 TTL0, TTL1, IP-OPTS,L2-SRC-MISS,L2-ACL-LOG,ICMP-REDIRECT
1 2 1000 SFLOW, L3-MTU-FAIL
2 4 300 MCAST, BCAST-CTRL
Control Plane Policing (CoPP) 247