Set Precedence - Cisco NCS 540 Series Routers Command Reference Manual

QoS Classification Commands

set precedence

To set the precedence value in the IP header, use the set precedence command in policy map class
configuration mode. To leave the precedence value unchanged, use the no form of this command.
set precedence [tunnel] value
no set precedence [tunnel] value
Syntax Description
tunnel
value
No default behavior or values
Command Default
Policy map class configuration
Command Modes
Command History
Release
Release 6.0
Precedence can be set using a number or corresponding name. After IP Precedence bits are set, other QoS
Usage Guidelines
services can then operate on the bit settings.
The set precedence command is supported only in the ingress direction. Unconditional precedence marking
is supported.
The network gives priority (or some type of expedited handling) to the marked traffic. IP precedence can be
set at the edge of the network (or administrative domain) and have queueing act on it thereafter.
The mapping from keywords such as 0 (routine) and 1 (priority) to a precedence value is useful only in some
instances. That is, the use of the precedence bit is evolving. You can define the meaning of a precedence value
by enabling other features that use the value. In the case of high-end Internet QoS, IP precedences can be used
to establish classes of service that do not necessarily correspond numerically to better or worse handling in
the network.
Task ID
Task
ID
qos
Examples
This example shows how to set the IP precedence to 5 (critical) for packets that match the access
control list named customer1:
RP/0/RP0/CPU0:router(config)# class-map class1
RP/0/RP0/CPU0:router(config-cmap)# match access-group ipv4 customer1
RP/0/RP0/CPU0:router(config-cmap)# exit
(Optional) Sets the IP precedence on the outer IP header.
Number or name that sets the precedence bits in the IP header. Range is from 0 to 7. Reserved
keywords can be specified instead of numeric values.
on page 22 describes the reserved keywords.
Operations
read,
write
Modular QoS Command Reference for Cisco NCS 5500 Series and Cisco NCS 540 Series Routers

set precedence

Table 3: IP Precedence Values and Names,
Modification
This command was introduced.
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