Set Precedence - Cisco CRS Command Reference Manual

set precedence

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
Command Default
Command Modes
Command History
Release 2.0
Release 3.8.0
Release 3.9.0
Usage Guidelines
To use this command, you must be in a user group associated with a task group that includes appropriate task
IDs. If the user group assignment is preventing you from using a command, contact your AAA administrator
for assistance.
Precedence can be set using a number or corresponding name. After IP Precedence bits are set, other QoS
services such as Modified Deficit Round Robin (MDRR) and Weighted Random Early Detection (WRED)
then operate on the bit settings.
Conditional marking marks the precedence values on the tunnel header as a policer action. Unconditional
marking marks the precedence tunnel as a policy action. Both conditional and unconditional markings are
supported only in an ingress direction. The tunnel keyword is available on Layer 2 (Ethernet only) and
Layer 3 interfaces in the ingress direction.
The network gives priority (or some type of expedited handling) to the marked traffic through the application
of MDRR or WRED at points downstream in the network. IP precedence can be set at the edge of the network
(or administrative domain) and have queueing act on it thereafter. MDRR can speed handling for
Cisco IOS XR Modular Quality of Service Command Reference for the Cisco CRS Router, Release 4.0
106
(Optional) Sets the IP precedence on the outer IP header. This command is available on
Layer 2 (Ethernet only) and Layer 3 interfaces in the ingress direction.
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.
Values and Names, on page 51
This command was introduced.
The tunnel keyword is supported for QoS in a Multicast Virtual Private
Network (mVPN) enabled network that requires both conditional and
unconditional marking of precedence bits on the tunnel header.
Support for the tunnel keyword on Layer 2 interfaces was added.
Quality of Service Commands on the Cisco IOS XR Software
describes the reserved keywords.
Table 3: IP Precedence
OL-23235-03