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KSZ9567R

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The ACL consists of three parts: matching rules, action rules, and processing entries. A matching rule specifies what

comparison test shall be performed on the incoming packet. It can also enable a counter function. An action rule spec-

ifies the forwarding action to be taken if the matching test succeeds. Alternatively, when a count function is enabled in

a matching rule, the 11-bit count value is stored in the corresponding action rule field and there is no forwarding action.

In general, the 16 matching rules are not directly linked to the 16 action rules. For example, matching entry #0 is not

necessarily related to action entry #0. The exception is when the counter function is enabled in a matching rule, whereby

the matching rule and action rule fields at the same ACL table entry will function together and are no longer independent.

Each of the 16 processing entries is used to link any number of matching rules (specified in RuleSet) to any one action

rule (specified in FRN). When there are multiple matching rules in a RuleSet, those rules are AND'ed together. Only if

all of those matching results are true will the FRN action be taken.

It is also possible to configure the ACL table so that multiple processing entries specify the same action rule. In this way,

the final matching result is the OR of the matching results from each of the multiple RuleSets.

The 16 ACL rules represent an ordered list, with entry #0 having the highest priority and entry #15 having the lowest

priority. All matching rules are evaluated. If there are multiple true match results and multiple corresponding actions, the

highest priority (lowest numbered) of those actions will be the one taken.

4.4.17.1

Processing Entry Description

The Processing Entry consists of two parameters as described in Table 4-15.

TABLE 4-15:

ACL PROCESSING ENTRY PARAMETERS

Parameter

Description

FRN[3:0]

First Rule Number

Pointer to an Action rule entry. Possible values are 0 to 15. If all Matching rules speci-

fied in the RuleSet are evaluated true, then this is the resulting Action rule.

RuleSet[15:0]

Specifies a set of one or more Matching rule entries.

RuleSet has one bit for each of the 16 Matching rule entries. If multiple Matching rules

are selected, then all conditions will be AND'ed to produce a final match result.

0 = Matching rule not selected

1 = Matching rule selected

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