monitor (OPTIONAL) Enter the keyword monitor when the rule isdescribing the traffic that you want to monitor and the ACLin which you are creating the rule is applied to the monitoredinterface.Defaults By default, 10 ACL logs are generated if you do not specify the threshold explicitly.The default frequency at which ACL logs are generated is five minutes. By default,flow-based monitoring is not enabled.CommandModesACCESS-LISTCommandHistory Version 9.4(0.0) Added support for flow-based monitoring on the S4810,S4820T, S6000, and Z9000 platforms.Version 9.3(0.0) Added support for logging of ACLs on the S4810, S4820T,and Z9000 platforms.UsageInformationWhen the configured maximum threshold is exceeded, generation of logs isstopped. When the interval at which ACL logs are configured to be recordedexpires, the subsequent, fresh interval timer is started and the packet count for thatnew interval commences from zero. If ACL logging was stopped previouslybecause the configured threshold is exceeded, it is re-enabled for this new interval.If ACL logging is stopped because the configured threshold is exceeded, it is re-enabled after the logging interval period elapses. ACL logging is supported forstandard and extended IPv4 ACLs, IPv6 ACLs, and MAC ACLs. You can configureACL logging only on ACLs that are applied to ingress interfaces; you cannot enablelogging for ACLs that are associated with egress interfaces.You can activate flow-based monitoring for a monitoring session by enteringtheflow-based enable command in the Monitor Session mode. When youenable this capability, traffic with particular flows that are traversing through theingress and egress interfaces are examined and, appropriate ACLs can be applied inboth the ingress and egress direction. Flow-based monitoring conservesbandwidth by monitoring only specified traffic instead all traffic on the interface.This feature is particularly useful when looking for malicious traffic. It is available forLayer 2 and Layer 3 ingress and egress traffic. You may specify traffic usingstandard or extended access-lists. This mechanism copies all incoming or outgoingpackets on one port and forwards (mirrors) them to another port. The source portis the monitored port (MD) and the destination port is the monitoring port (MG).permit (for IPv6 ACLs)To configure a filter that matches the filter criteria, select an IPv6 protocol number, ICMP, IPv6, TCP, orUDP.Syntax permit {ipv6-protocol-number | icmp | ipv6 | tcp | udp} [count[byte]] [dscp value] [order] [fragments] [log [intervalminutes] [threshold-in-msgs [count]] [monitor]Access Control Lists (ACL) 337
