match precedence
To identify IP precedence values as match criteria, use the
match precedence
command in class map
configuration mode. To remove precedence values from a class map, use the
no
form of this command.
match
[
not
]
precedence
[{
ipv4|ipv6
}]
precedence-value
[
precedence-value1
...
precedence-value7
]
no match
[
not
]
precedence
[{
ipv4|ipv6
}]
precedence-value
[
precedence-value1
...
precedence-value7
]
Syntax Description
(Optional) Negates the specified match result.
not
(Optional) Specifies the IPv4 precedence value.
ipv4
(Optional) Specifies the IPv6 precedence value.
ipv6
An IP precedence value identifier that specifies the exact value. Reserved keywords can
be specified instead of numeric values.
Table 3: IP Precedence Values and Names, on
page 22
describes the reserved keywords.
Up to eight precedence values can be matched in one match statement.
precedence-value
Command Default
Matching on both IP Version 4 (IPv4) and IPv6 packets is the default.
Command Modes
Class map configuration
Command History
Modification
Release
This command was introduced.
Release 6.0
Usage Guidelines
The
match precedence
command is supported only in the ingress direction. The minimum value is 0 and
maximum value is 7. The maximum allowed entries: 8.
The
match precedence
command specifies a precedence value that is used as the match criteria against which
packets are checked to determine if they belong to the class specified by the class map.
To use the
match precedence
command, you must first enter the
class-map
command to specify the name
of the class whose match criteria you want to establish. If you specify more than one
match precedence
command in a class map, the new values are added to the existing statement.
The
match precedence
command examines the higher-order three bits in the type of service (ToS) byte of
the IP header. Up to eight precedence values can be matched in one match statement. For example,
match
precedence ipv4 0 1 2 3 4 5 6 7
returns matches for IP precedence values of 0, 1, 2, 3, 4, 5, 6, and 7. Only
one of the eight values is needed to yield a match (OR operation).
The precedence values are used as a matching criterion only. The value has no mathematical significance.
For instance, the precedence value 2 is not greater than 1. The value simply indicates that a packet marked
with the precedence value of 2 is different than a packet marked with the precedence value of 1. The treatment
of these different packets is defined by the user through the setting of QoS policies in policy map class
configuration mode.
This table lists the IP precedence value number and associated name in descending order of importance.
Modular QoS Command Reference for Cisco NCS 5500 Series and Cisco NCS 540 Series Routers
21
QoS Classification Commands
match precedence