Users Guide

monitor (OPTIONAL) Enter the keyword monitor when the rule is describing the trac 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 ve minutes. By default, ow-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 ow-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 congured maximum threshold is exceeded, generation of logs is stopped. When the interval at which
ACL logs are congured 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 congured
threshold is exceeded, it is re-enabled for this new interval.
If ACL logging is stopped because the congured 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 congure 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 ow-based monitoring for a monitoring session by entering the flow-based enable
command in the Monitor Session mode. When you enable this capability, trac with particular ows 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 specied trac
instead all trac on the interface. This feature is particularly useful when looking for malicious trac. It is available
for Layer 2 and Layer 3 ingress and egress trac. You may specify trac 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 lter to deny TCP packets.
deny udp — assigns a lter to deny UDP packets.
ip access-list extended — creates an extended ACL.
deny icmp
To drop all or specic internet control message protocol (ICMP) messages, congure a lter.
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 lter, you have two choices:
164 Access Control Lists (ACL)