IPv4 Access Control Lists (ACLs)

Monitoring Static ACL Performance

ACE Counter Operation: For a given ACE in an assigned ACL, the counter increments by 1 each time the switch detects a packet that matches the criteria in that ACE, and maintains a running total of the matches since the last counter reset.

For example, in ACL line 10 below, there has been a total of 37 matches on the ACE since the last time the ACL’s counters were reset.

Total

(

37)

10 permit icmp 10.10.20.3

Note: This ACL monitoring feature does not include hits on the “implicit deny” that is included at the end of all ACLs.

Resetting ACE Hit Counters to Zero:

Removing an ACL from an interface zeros the ACL’s ACE counters for that interface only.

For a given ACL, either of the following actions clear the ACE counters to zero for all interfaces to which the ACL is assigned.

adding or removing a permit or deny ACE in the ACL

rebooting the switch

9-93