• For IP packets that contain the transport layer protocol as Transmission Control Protocol (TCP) or User Datagram Protocol (UDP), theACL name, sequence number, ACL action (permit or deny), source and destination MAC addresses, source and destination IPaddresses, and the source and destination ports (Layer 4 parameters) are also recorded.If the packet contains an unidentified EtherType or transport layer protocol, the values for these parameters are saved as Unknown in thelog message. If you also enable the logging of the count of packets in the ACL entry, and if the logging is deactivated in a specific intervalbecause the threshold has exceeded, the count of packets that exceeded the logging threshold value during that interval is recorded whenthe subsequent log record (in the next interval) is generated for that ACL entry.Guidelines for Configuring ACL LoggingThis functionality is supported on the platform.Keep the following points in mind when you configure logging of ACL activities:• During initialization, the ACL logging application tags the ACL rule indices for which a match condition exists as being in-use, whichensures that the same rule indices are not reused by ACL logging again.• The ACL configuration information that the ACL logging application receives from the ACL manager causes the allocation and clearanceof the match rule number. A unique match rule number is created for the combination of each ACL entry, sequence number, andinterface parameters.• A separate set of match indices is preserved by the ACL logging application for the permit and deny actions. Depending on the actionof an ACL entry, the corresponding match index is allocated from the particular set that is maintained for permit and deny actions.• A maximum of 125 ACL entries with permit action can be logged. A maximum of 126 ACL entries with deny action can be logged.• For virtual ACL entries, the same match rule number is reused. Similarly, when an ACL entry is deleted that was previously enabled forACL logging, the match rule number used by it is released back to the pool or available set of match indices so that it can be reused forsubsequent allocations.• If you enabled the count of packets for the ACL entry for which you configured logging, and if the logging is deactivated in a specificinterval owing to the threshold having exceeded, the count of packets that exceeded the logging threshold value during that interval islogged when the subsequent log record (in the next interval) is generated for that ACL entry.• When you delete an ACL entry, the logging settings associated with it are also removed.• ACL logging is supported for standard and extended IPv4 ACLs, IPv6 ACLs, and standard and extended MAC ACLs.• For ACL entries applied on port-channel interfaces, one match index for every member interface of the port-channel interface isassigned. Therefore, the total available match indices of 251 are split (125 match indices for permit action and 126 match indices for thedeny action).• You can configure ACL logging only on ACLs that are applied to ingress interfaces; you cannot enable logging for ACLs on egressinterfaces.• The total available match rule indices is 255 with four match indices used by other modules, leaving 251 indices available for ACLlogging.Configuring ACL LoggingThis functionality is supported on the platform.To configure the maximum number of ACL log messages to be generated and the frequency at which these messages must be generated,perform the following steps:NOTE: This example describes the configuration of ACL logging for standard IP access lists. You can enable the loggingcapability for standard and extended IPv4 ACLs, IPv6 ACLs, and standard and extended MAC ACLs.1 Specify the maximum number of ACL logs or the threshold that can be generated by using the threshold-in-msgs countoption with the seq, permit, or deny commands. Upon exceeding the specified maximum limit, the generation of ACL logs isterminated. You can enter a threshold in the range of 1-100. By default, 10 ACL logs are generated if you do not specify the thresholdexplicitly.136 Access Control Lists (ACLs)
