Cisco 3845 Software Guide - Page 522

Configuring QoS Chapter 27 Configuring QoS This example uses a policy map to remark a packet. The first marking (the set command) applies to the QoS default class map that matches all traffic not matched by class AF31-AF33 and sets all traffic to an IP DSCP value of 1. The second marking sets the traffic in classes AF31 to AF33 to an IP DSCP of 3. Switch(config)# policy-map Example Switch(config-pmap)# class class-default Switch(config-pmap-c)# set ip dscp 1 Switch(config-pmap-c)# exit Switch(config-pmap)# class AF31-AF33 Switch(config-pmap-c)# set ip dscp 3 Switch(config-pmap-c)# exit Switch(config-pmap)# exit Switch(config)# interface gigabitethernet 0/1 Switch(config-if)# service-policy input Example Switch(config-if)# exit Configuring Policing Policing is used to enforce a traffic-metering profile. A policer meters a particular traffic flow and determines if a packet in the given flow conforms to the specified rate. You use the police policy-map class configuration command to configure individual policers to define the committed rate limitations, committed burst size limitations of the traffic, and the action to take for a class of traffic. The switch supports 1-rate policing with a 2-color marker, or 2-rate policing with a 3-color marker. Mapped packets can be sent without modification, dropped, or marked to options specified by the set command. Note that traffic rates are configured in bits per second and burst size is entered in bytes. Follow these guidelines when configuring policing. • Hierarchical policing is not supported. • You can configure policing for any number of classes on any one of the three levels of the policy-map hierarchy. If you configure marking on one level, you can configure policing without marking (transmit, drop) on another level. Configuring a Policy Map with 1-Rate, 2-Color Policing I Step 1 Step 2 Step 3 Beginning in privileged EXEC mode, follow these steps to create a 1-rate, 2 color input policy map with individual policing: Command configure terminal class {class-map-name | class-default} policy-map policy-map-name Purpose Enter global configuration mode. Enter a class-map name or class-default to match all unclassified packets, and enter policy-map class configuration mode. If you enter a class-map name, you must have already created the class map by using the class-map global configuration command. Create a policy map by entering the policy map name, and enter policy-map configuration mode. By default, no policy maps are defined. 27-34 Cisco ME 3800X and 3600X Switch Software Configuration Guide OL-23400-01