Cisco Catalyst 4500 Series Command Reference Guide

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Catalyst 4500 Series Switch Cisco IOS Command Reference—Release IOS XE 3.4.0SG and IOS 15.1(2)SG)
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Chapter 2 Cisco IOS Commands for the Catalyst 4500 Series Switches
priority
priority
To enable the strict priority queue (low-latency queueing [LLQ]) and to give priority to a class of traffic
belonging to a policy map attached to a physical port, use the priority policy-map class configuration
command. To return to the default setting, use the no form of this command.
priority
no priority
Syntax Description This command has no arguments or keywords.
Defaults The strict priority queue is disabled.
Command Modes Policy-map class configuration mode
Command History
Usage Guidelines Use the priority command only in a policy map attached to a physical port. You can use this command
only in class-level classes, you cannot use this command in class class-default.
This command configures LLQ and provides strict-priority queueing. Strict-priority queueing enables
delay-sensitive data, such as voice, to be sent before packets in other queues are sent. The priority queue
is serviced first until it is empty.
You cannot use the bandwidth, dbl, and the shape policy-map class configuration commands with the
priority policy-map class configuration command in the same class within the same policy map.
However, you can use these commands in the same policy map.
You can use police or set class configuration commands with the priority police-map class configuration
command.
If the priority queuing class is not rate limited, you cannot use the bandwidth command, you can use the
bandwidth remaining percent command instead.
Examples This example shows how to enable the LLQ for the policy map called policy1:
Switch# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)# policy-map policy1
Switch(config-pmap)# class voice
Switch(config-pmap-c)# priority
You can verify your settings by entering the show policy-map privileged EXEC command.
Release Modification
12.2(40)SG Support introduced on Supervisor Engine 6E and Catalyst 4900M.

Cisco Catalyst 4500 Series Specifications

General

Series	Catalyst 4500 Series
Category	Switch
Layer Support	Layer 2, Layer 3
Form Factor	Modular chassis
Stackable	No
Chassis Slots	3, 6, 7, 10
Power Supply Options	AC, DC
Redundancy	Power supply, Supervisor engine
Network Management	Cisco IOS Software CLI, SNMP, Cisco Prime Infrastructure
Features	Security, QoS
Port Density	Up to 384 ports per chassis
Security Features	802.1X, ACLs, DHCP Snooping, Dynamic ARP Inspection, IP Source Guard
Supervisor Engine	8-E