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 — assigns a filter to deny IP traffic.
deny udp — assigns a filter to deny UDP traffic.
deny ether-type (for Extended MAC ACLs)Configure an egress filter that drops specified types of Ethernet packets on egress ACL supported line
cards. (For more information, refer to your line card documentation).
Syntax deny ether-type protocol-type-number {destination-mac-address
mac-address-mask | any} vlan vlan-id {source-mac-address mac-
address-mask | any} [count [byte]] [order] [log [interval
minutes] [threshold-in-msgs [count]] [monitor]
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 ether-type protocol-type-number {destination-
mac-address mac-address-mask | any} vlan vlan-id {source-
mac-address mac-address-mask | any} command.
Parameters log (OPTIONAL) Enter the keyword log to enable the triggering
of ACL log messages.
Access Control Lists (ACL) 277