Dell PowerSwitch S4128F-ON OS10 Enterprise Edition User Guide Release 10.4.3.0 - Page 968

Control-plane policing Control-plane policing (CoPP) increases security on the system by protecting the route processor from unnecessary traffic and giving priority to important control plane and management traffic. CoPP uses a dedicated control plane configuration through the QoS CLIs to set rate-limiting capabilities for control plane packets. If the rate of control packets towards the CPU is higher than the packet rate that the CPU can handle, CoPP provides a method to selectively drop some of the control traffic so that the CPU can process high-priority control traffic. You can use CoPP to rate-limit traffic through each CPU port queue of the network processor (NPU). CoPP applies policy actions on all control-plane traffic. The control-plane class map does not use any match criteria. To enforce rate-limiting or rate policing on control-plane traffic, create policy maps. You can use the control-plane command to attach the CoPP service policies directly to the control-plane. Starting from release 10.4.2, the default rate limits change from 12 to 21 CPU queues and the protocols mapped to each CPU queue. NOTE: When you upgrade from a previous release to release 10.4.2 and you have CoPP policy with rate limits configured in the previous release, the CoPP policies are automatically remapped based on the new CoPP protocol mappings to queues. For example: • You have a CoPP policy configured for queue 5 in release 10.4.1, which is for ARP Request, ICMPv6-RS-NS, iSCSI snooping, and iSCSI-COS. • After upgrade to release 10.4.2, the CoPP policy for queue 5 is remapped based on the new CoPP protocol mappings to queues as follows: - ARP Request is mapped to queue 6 - ICMPv6-RS-NS is mapped to queue 5 - iSCSI is mapped to queue 0 The rate limit configuration in CoPP policy before upgrade is automatically remapped to queues 6, 5, and 0 respectively after upgrade. For example, in release 10.4.1, the following policy configuration is applied on queue 5, which in 10.4.1 is mapped to ARP_REQ, ICMPV6_RS, ICMPV6_NS, and ISCSI protocols: policy-map type control-plane test ! class test set qos-group 5 police cir 300 pir 300 After upgrade to release 10.4.2, the policy configuration appears as follows: policy-map type control-plane test ! class test_Remapped_0 set qos-group 0 police cir 300 pir 300 ! class test_Remapped_5 set qos-group 5 police cir 300 pir 300 ! class test_Remapped_6 set qos-group 6 police cir 300 pir 300 In release 10.4.2, ARP_REQ is mapped to queue 6, ICMPV6_RS and ICMPV6_NS are mapped to queue 5, and ISCSI is mapped to queue 0. 968 Quality of service