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Cisco ME 3800X and 3600X Switch Software Configuration Guide
OL-23400-01
Chapter 27 Configuring QoS
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
Beginning in privileged EXEC mode, follow these steps to create a 1-rate, 2 color input policy map with
individual policing:
I
Command
Purpose
Step 1
configure terminal
Enter global configuration mode.
Step 2
class {class-map-name |
class-default}
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.
Step 3
policy-map policy-map-name
Create a policy map by entering the policy map name, and enter policy-map
configuration mode. By default, no policy maps are defined.
