Allied Telesis AT-S63 - Manual (Page 280)

Chapter 13: Classifiers
280 Section II: Advanced Operations
Classifier
Guidelines
Follow these guidelines when creating a classifier:
ˆ Each classifier represents a separate traffic flow.
ˆ The variables within a classifier are linked by AND. The more variables
defined within a classifier, the more specific it becomes in terms of the
flow it defines. For instance, specifying both a source IP address and a
TCP destination port within the same classifier defines a traffic flow
that relates to IP packets containing both the designated source IP
address and TCP destination port. However, there are some
restrictions on combining variables in the same classifier. For the
restrictions, refer to “Classifier Criteria” on page 275.
ˆ The same classifier can be applied to both an ACL and a QoS policy.
ˆ You can apply the same classifier to more than one ACL or QoS policy.
ˆ A classifier without any defined variables applies to all packets.
ˆ You cannot create two classifiers that have the same settings. There
can be only one classifier for any given type of traffic flow.
ˆ A classifier can have a maximum of eight defined criteria, not including
the classifier ID number and the description.
ˆ The switch can store up to 256 classifiers. However, the maximum
number of classifiers that you can assign to active access control lists
and QoS policies at any one time will be from 14 to 127. The number
depends on several factors, such as the number of ports to which the
classifiers are assigned and the types of criteria defined in the
classifiers.
ˆ You cannot modify a classifier if it belongs to an ACL or QoS policy
assigned to a port. You must remove the port assignments from the
ACL or policy and reassign them after modifying the classifier.
ˆ You cannot delete a classifier if it belongs to an ACL or QoS policy.
You must remove a classifier from its ACLs and QoS policies before
you can delete it.