Administrator Guide

1510 Differentiated Services
parallel at once, and the priority of the ACL is used to implement the
conceptual match process. There are no counters instantiated for ACLs
referred to by a class-map.
An ACL that is used in a class-map match term itself has one or more permit
and/or deny rules. The incoming packet is matched sequentially against the
permit rules in each ACL in the match list, in order, and a match/no match
decision is reached. If a permit rule in an ACL in the list matches, the ACL
match criteria is met and no further match processing takes place in the class-
map. If a deny rule in an access-group in the list matches, the ACL no match
criteria is met and no further match processing takes place.
ACLs in an access-group referred to in a class map do not have counters
enabled. The hit counts will always be zero.
If none of the rules in an access-group matches, the packet match is
attempted against the next access-group in the class-map match list. Once a
match has occurred, if the decision reached in the above step is match, then
DiffServ executes the action specified in the set term(s) of the DiffServ
policy.
If the decision reached in the above step is no match, then DiffServ does not
apply any action that is specified in set term(s) in the policy-map statement.
The processing logic terminates, and the packet goes through the standard
destination-based switching logic.
The switch supports either access-group match criteria or regular DiffServ
match criteria in a policy map, but not both. If match criteria other than a
match access-group are configured in a policy, configuration of access-group
match criteria is rejected and vice-versa.
Default DiffServ Values
Table 43-1 shows the global default values for DiffServ.
Table 43-1. DiffServ Global Defaults
Parameter Default Value
DiffServ Enabled
Classes None configured
Policies None configured