Allied Telesis AT-S63 - Manual (Page 134)

Chapter 11: Classifiers
134 Section II: Advanced Operations
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
you define 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 the TCP destination port. There are, however, some
restrictions on combining variables in the same classifier. For the
restrictions, refer to “Classifier Criteria” on page 129.
ˆ The same classifier can belong to ACLs and QoS policies.
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 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
that is 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.