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Cisco ASR 901 Aggregation Services Router Command Reference Guide
OL-26031-07
Chapter 1 CLI Command Reference
set ip precedence (route-map)
The network gives priority (or some type of expedited handling) to marked traffic through the application
of WFQ or WRED at points downstream in the network. Typically, you set IP Precedence at the edge of
the network (or administrative domain); data then is queued based on the precedence. WFQ can speed
up handling for certain precedence traffic at congestion points. WRED can ensure that certain
precedence traffic has lower loss rates than other traffic during times of congestion.
The mapping from arguments such as
routine
and
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 the high-end Internet QoS available
from Cisco, IP Precedences can be used to establish classes of service that do not necessarily correspond
numerically to better or worse handling in the network.
Use the
route-map
(IP)
global configuration command with the
match
and
set
route-map configuration
commands to define the conditions for redistributing routes from one routing protocol into another, or
for policy routing. Each
route-map
command has an associated list of
match
and
set
commands. The
match
commands specify the match criteria—the conditions under which redistribution or policy
routing is allowed for the current
route-map
command. The
set
commands specify the set actions—the
particular redistribution or policy routing actions to perform if the criteria enforced by the
match
commands are met. The
no route-map
command deletes the route map.
The
set
route-map configuration commands specify the redistribution set actions to be performed when
all of the match criteria of a route map are met.
Examples
The following example sets the IP Precedence to 5 (critical) for packets that pass the route map match:
interface gigabitethernet0/1
ip policy route-map texas
route-map texas
match length 68 128
set ip precedence 5
Related Commands
Command
Description
random-detect dscp
Changes the minimum and maximum packet thresholds for the DSCP
value.
