DELL 9.8(0.0) User Manual

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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
permit icmp (for IPv6 ACLs)
To allow all or specific internet control message protocol (ICMP) messages, configure a filter.
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.
362
Access Control Lists (ACL)