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which the generation of ACL logs is terminated with the seq, permit, or deny
commands. The threshold range is from 1 to 100.
interval minutes (OPTIONAL) Enter the keyword interval followed by the time period in minutes
at which ACL logs must be generated. The time interval range is from 1 to 10
minutes.
monitor (OPTIONAL) Enter the keyword monitor when the rule is describing the traffic
that you want to monitor and the ACL in which you are creating the rule is applied
to the monitored interface.
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.
Command Modes CONFIGURATION-EXTENDED-ACCESS-LIST
Supported Modes Full–Switch
Command
History
Version Description
9.9(0.0) Introduced on the FN IOM.
9.4(0.0) Added support for flow-based monitoring on the MXL 10/40GbE Switch IO Module
platform.
9.3(0.0) Added support for logging of ACLs on the MXL 10/40GbE Switch IO Module
platform.
Usage
Information
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 tcp — assigns a filter to deny TCP packets.
deny udp — assigns a filter to deny UDP packets.
ip access-list extended — creates an extended ACL.
deny icmp
To drop all or specific internet control message protocol (ICMP) messages, configure a filter.
Syntax
deny icmp {source mask | any | host ip-address} {destination mask | any
| host ip-address} [dscp] [count [byte]] [order] [fragments][threshold-in-
msgs] [count]]
To remove this filter, you have two choices:
● Use the no seq sequence-number command, if you know the filter’s sequence number.
● Use the no deny icmp {source mask | any | host ip-address} {destination
mask | any | host ip-address} command.
152 Access Control Lists (ACL)