Service Manual

Defaults By default 10 ACL logs are generated if you do not specify the threshold explicitly. The default frequency at which
the ACL logs are generated is five minutes. By default, the flow-based monitoring is not enabled.
Command Modes CONFIGURATION-IP ACCESS-LIST-EXTENDED
Command History
Version Description
9.9(0.0) Introduced on the FN IOM.
9.4(0.0) Added support for the flow-based monitoring on the MXL 10/40GbE Switch IO Module.
9.3(0.0) Added support for logging of ACLs on the MXL 10/40GbE Switch IO Module.
8.3.16.1 Introduced on the MXL 10/40GbE Switch IO Module.
Usage Information
The order option is relevant in the context of the Policy QoS feature only. The following applies:
• The seq sequence-number command is applicable only in an ACL group.
• The order option works across ACL groups that have been applied on an interface via the QoS policy
framework.
• The order option takes precedence over seq sequence-number.
• If sequence-number is not configured, the rules with the same order value are ordered according to their
configuration order.
• If sequence-number is configured, the sequence-number is used as a tie breaker for rules with the same
order.
If you configure the sequence-number, the sequence-number is used as a tie breaker for rules with the
same order.
When the configured maximum threshold is exceeded, generation of logs is stopped. When the interval at which
ACL logs are configured to be recorded expires, the subsequent, fresh interval timer is started and the packet
count for that new interval commences from zero. If ACL logging was stopped previously because 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 for standard and extended IPv4 ACLs, IPv6 ACLs, and MAC ACLs. You
can configure ACL logging only on ACLs that are applied to ingress interfaces; you cannot enable logging for ACLs
that are associated with egress interfaces.
You can activate flow-based monitoring for a monitoring session by entering the flow-based enable
command in the Monitor Session mode. When you enable this capability, traffic with particular flows that are
traversing through the ingress and egress interfaces are examined and, appropriate ACLs can be applied in both
the ingress and egress direction. Flow-based monitoring conserves bandwidth by monitoring only specified traffic
instead all traffic on the interface. This feature is particularly useful when looking for malicious traffic. It is available
for Layer 2 and Layer 3 ingress and egress traffic. You may specify traffic using standard or extended access-lists.
This mechanism copies all incoming or outgoing packets on one port and forwards (mirrors) them to another port.
The source port is the monitored port (MD) and the destination port is the monitoring port (MG).
Related Commands
deny — Configures a filter to drop packets.
permit — Configures a filter to forward packets.
Access Control Lists (ACL) 171