Brocade Communications Systems 53-1002163-02 Multicast rate limiting, Enabling an Ethernet PFC

11 Multicast rate limiting

•Both ends of a link must be configured identically for Ethernet Pause or Ethernet Priority Flow Control because they are incompatible.

Enabling an Ethernet PFC

To enable Ethernet PFC, perform the following steps from privileged EXEC mode. 1. Enter global configuration mode.

switch#configure terminal

2. Specify the 10-gigabit Ethernet interface.

switch(config)#interface tengigabitethernet 0/2

3. Enable trust mode on the interface.

switch(conf-if-te-0/2)#qos trust cos

4. Enable an Ethernet PFC on the interface.

switch(conf-if-te-0/2)#qos flowcontrol pfc 3 tx on rx on

5. Enter the copy command to save the running-config file to the startup-config file.

switch(config)#do copy running-config startup-config

Multicast rate limiting

Multicast rate limiting provides a mechanism to control multicast frame replication and cap the effect of multicast traffic.

Multicast rate limit is applied to the output of each multicast receive queue. Rate limits apply equally to ingress receive queueing (first level expansion) and egress receive queueing (second level expansion) since the same physical receive queues are utilized. You can set policies to limit the maximum multicast frame rate differently for each traffic class level and cap the total multicast egress rate out of the system.

Multicast rate limiting includes the following features:

•All configuration parameters are applied globally. Multicast rate limits are applied to multicast receive queues as frame replications are placed into the multicast expansion queues. The same physical queues are used for both ingress receive queues and egress receive queues so rate limits are applied to both ingress and egress queueing.

•Four explicit multicast rate limit values are supported, one for each traffic class. The rate limit values represent the maximum multicast expansion rate in packets per second (PPS).

Creating a receive queue multicast rate-limit

To create the receive queue multicast rate-limit, perform the following steps from privileged EXEC mode.

1. Enter global configuration mode.

switch#configure terminal

2.Create a lower maximum multicast frame expansion rate. In this example, the rate is to 10000 PPS.

switch(config)#qos rcv-queue multicast rate-limit 10000 burst 5000

116	Converged Enhanced Ethernet Administrator’s Guide
	53-1002163-02