Configuring A Default Traffic Class; How Commands "Class-Map Match-Any" And "Class-Map Match-All" Differ - Cisco cBR 8 Configuration Manual

Modular Quality of Service Command-Line Interface QoS

Configuring a Default Traffic Class

Traffic that does not meet the match criteria specified in the traffic classes (that is, unclassified traffic) is
treated as belonging to the default traffic class.
If you do not configure a default class, packets are still treated as members of that class. The default class has
no QoS features enabled so packets belonging to this class have no QoS functionality. Such packets are placed
into a first-in, first-out (FIFO) queue managed by tail drop, which is a means of avoiding congestion that
treats all traffic equally and does not differentiate between classes of service. Queues fill during periods of
congestion. When the output queue is full and tail drop is active, packets are dropped until the congestion is
eliminated and the queue is no longer full.
The following example configures a policy map (policy1) for the default class (always called class-default)
with these characteristics: 10 queues for traffic that does not meet the match criteria of other classes whose
policy is defined by class policy1, and a maximum of 20 packets per queue before tail drop is enacted to
handle additional queued packets.
In the following example, we configure a policy map (policy1) for the default class (always termed class-default)
with these characteristics: 10 queues for traffic that does not meet the match criterion of other classes whose
policy is defined by the traffic policy policy1.
policy-map policy1
class class-default

How Commands "class-map match-any" and "class-map match-all" Differ

This example shows how packets are evaluated when multiple match criteria exist. It illustrates the difference
between the class-map match-any and class-map match-all commands. Packets must meet either all of the
match criteria (match-all) or one of the match criteria (match-any) to be considered a member of the traffic
class.
The following examples show a traffic class configured with the class-map match-all command:
class-map match-all cisco1
match qos-group 4
match access-group 101
If a packet arrives on a router with traffic class cisco1 configured on the interface, we assess whether it matches
the IP protocol, QoS group 4, and access group 101. If all of these match criteria are met, the packet is classified
as a member of the traffic class cisco1 (a logical AND operator; Protocol IP AND QoS group 4 AND access
group 101).
class-map match-all vlan
match vlan 1
match vlan inner 1
The following example illustrates use of the class-map match-any command. Only one match criterion must
be met for us to classify the packet as a member of the traffic class (i.e., a logical OR operator; protocol IP
OR QoS group 4 OR access group 101):
class-map match-any cisco2
match protocol ip
match qos-group 4
shape average 100m
Cisco cBR Series Converged Broadband Routers Quality of Services Configuration Guide for Cisco IOS XE Fuji
Configuring a Default Traffic Class
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