8-4
Classifier-Based Software Configuration
Traffic Classes
Creating a Traffic Class
In the traffic class-based configuration model, you use match criteria to create
a class of IPv4 or IPv6 traffic and select the packets you want to manage. In a
traffic class configuration, match criteria consist of match and ignore com-
mands. These commands determine the packets that belong to a class. (Match/
ignore criteria are modelled on the permit/deny criteria used in ACLs.)
The traffic classes you configure can be used later in the service policies you
create for different software features, such as QoS and port mirroring. The
match criteria used in match/ignore statements are the same across software
features.
Using Match Criteria
To identify the packets that belong to a traffic class for further processing by
policy actions, use match and ignore commands in a class configuration:
■ match commands define the values that header fields must contain for a
packet to belong to the class and be managed by policy actions.
■ ignore commands define the values which, if contained in header fields,
exclude a packet from the policy actions configured for the class. An
ignored packet is transmitted without having a policy action performed
on it.
The switch compares match/ignore statements to the values in packet fields.
It compares the specified criteria in the sequential order in which the state-
ments are entered in the class, until a match is found. Be sure to enter match/
ignore statements in the precise order in which you want their criteria to be
used to check packets.
■ As soon as a field in a packet header matches the criteria in a match
statement, the sequential comparison of match criteria in the class stops,
and the policy actions configured for the class are executed on the packet
(see “Creating a Service Policy” on page 8-25).
■ If a packet matches the criteria in an ignore statement, the sequential
comparison of match criteria in the class stops, and no policy action is
performed on the packet.
If a packet does not match the criteria in any match/ignore statement in a
traffic class configuration, one of the following actions is taken:
■ The packet is transmitted without a policy action performed on it.