Matching rules of ACL

The display order of ACL rules determines the ACL matching principles. During ACL matching, a look-up is performed from the first rule displayed in the ACL. When one rule matches, the look-up is completed. The earlier a rule is displayed, the easier for it to be matched. The factors that determine the display order are the rule ID and matching methods.
Matching methods include matching in configuration order or in automatic order. If the configuration order is used, the matching will be performed according to the order in which the ACL rules are configured. Rule IDs can be set by users, or can be automatically generated by the system based on the step, which is convenient for rule maintenance and insertion of new rules. For example, the default step of ACL is 5. If the user does not set a rule ID, the first rule ID automatically generated by the system is 5. When the user needs to insert a new rule before rule 5, a rule ID smaller than 5 can be set. The new rule now is the first rule.
If the automatic order is used, the system automatically generates rule IDs, and ranks the rules with the highest precision to the top of the list. This can be achieved by comparing the length of the wildcard characters of addresses. The shorter the length is, the smaller the assigned NE range is.

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