Reference Guide

You can activate flow-based monitoring for a monitoring session by entering
theflow-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).
permit icmp (for IPv6 ACLs)
Allow filtering of all or specific internet control message protocol (ICMP) messages
C9000 Series
Syntax
permit icmp {source address mask | any | host ipv6-address}
{destination address | any | host ipv6-address} [message-type]
[count [byte]] [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 permit icmp {source address mask | any | host ipv6-
address} {destination address | any | host ipv6-address}
command.
Parameters
log (OPTIONAL) Enter the keyword log to enable the triggering
of ACL log messages.
threshold-in msgs
count
(OPTIONAL) Enter the threshold-in-msgs keyword
followed by a value to indicate the maximum number of
ACL logs that can be generated, exceeding 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 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.
1174
IPv6 Access Control Lists (IPv6 ACLs)