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Catalyst 3750 Metro Switch Command Reference
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Chapter 2 Catalyst 3750 Metro Switch Cisco IOS Commands
priority
priority
Use the
priority
policy-map class configuration command to enable the strict priority queue
(low-latency queueing [LLQ]) and to give priority to a class of traffic belonging to a hierarchical policy
map attached to an enhanced-services (ES) port. Use the
no
form of this command to return to the default
setting.
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
Command History
Usage Guidelines
Use the
priority
command only in a hierarchical policy map attached to an ES port. You can use this
command only in class-level classes.
This command configures LLQ and provides strict-priority queueing for class-based weighted fair
queueing (CBWFQ). 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
,
queue-limit
,
random-detect
, 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.
Within a policy map, you can give priority status to only one class.
When you attach the policy map containing class policy configurations to the port to stipulate the service
policy for that port, the available bandwidth is determined.
To avoid a loss of priority traffic on an ES port when the switch is congested, you can configure both the
strict-priority queueing and egress priority queueing features. Note that when you map certain traffic
classes to the egress priority queue, they are not automatically placed into the strict-priority queue. You
must configure both the
priority
policy-map class configuration and the
priority-queue out
interface
configuration commands. For more information, see the
“priority-queue” section on page 2-365
.
Release
Modification
12.1(14)AX
This command was introduced.
12.2(25)EY
Hierarchical service policies can be attached to inbound traffic received on
an ES port.
