Allied Telesis AT-S62 - Manual (Page 240)

Chapter 13: Classifiers
240 Section II: Advanced Operations
Classifier
Guidelines
Here are the guidelines to follow 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
specified within a classifier, the more specific it becomes in terms of
the defined flow. 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. There are restrictions on which
variables can be used together in the same classifier. For the
restrictions, refer to “Classifier Criteria” on page 235.
ˆ You can apply the same classifier to more than one ACL or QoS policy.
ˆ A classifier can be used for both ACLs and QoS policies.
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 The switch can store up to 256 classifiers. However, the maximum
number of classifiers that you can assign to 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 first remove the port assignments
from the ACL or policy and reassign them after you modify the
classifier.
ˆ You cannot delete a classifier if it is assigned to an ACL or QoS policy.
You must first remove a classifier from its ACLs and QoS policies
before you can delete it.