Administrator Guide

Command
Modes
ACCESS-LIST
Command
History
Version 9.3.0.0 Added support for logging of ACLs on the S4810, S4820T,
and Z9000 platforms.
Version 9.4(0.0) Added support for flow-based monitoring on the S4810,
S4820T, S6000, and Z9000 platforms.
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).
deny (for IPv6 ACLs)
Configure a filter that drops IPv6 packets that match the filter criteria.
Syntax
deny {ipv6-protocol-number | icmp | ipv6 | tcp | udp} [count
[byte]] [dscp value] [order] [fragments] [log [interval
minutes] [threshold-in-msgs [count]] [monitor]
To remove this filter, you have two choices:
• Use the no seq sequence-number command syntax if you know the filter’s
sequence number
• Use the no deny {ipv6-protocol-number | icmp | ipv6 | tcp |
udp}
command
Parameters
log (OPTIONAL) Enter the keyword log to enable the triggering
of ACL log messages.
314
Access Control Lists (ACL)