CLI Guide

• The order option works across ACL groups that have been applied on an interface via the QoS policy
framework.
• The order option takes precedence over seq sequence-number.
• If sequence-number is not congured, the rules with the same order value are ordered according to their
conguration order.
• If sequence-number is congured, the sequence-number is used as a tie breaker for rules with the same
order.
When you use the log option, the CP processor logs details about the packets that match. Depending on how
many packets match the log entry and at what rate, the CP may become busy as it has to log these packets’
details.
You cannot include IP, TCP, or UDP (Layer 3) lters in an ACL congured with ARP or Ether-type (Layer 2) lters.
Apply Layer 2 ACLs to interfaces in Layer 2 mode.
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).
NOTE
: When ACL logging and byte counters are congured simultaneously, byte counters may display
an incorrect value. Congure packet counters with logging instead.
seq
Assign a sequence number to a deny or permit lter in an extended IP access list while creating the lter.
Syntax
seq sequence-number {deny | permit} {source [mask] | any | host ip-address}}
[count [byte] [dscp value] [order] [fragments] [threshold-in-msgs [count]
Parameters
sequence-number Enter a number from 0 to 4294967290. The range is from 0 to 65534.
deny Enter the keyword deny to congure a lter to drop packets meeting this condition.
permit Enter the keyword permit to congure a lter to forward packets meeting this criteria.
source Enter an IP address in dotted decimal format of the network from which the packet was
received.
mask (OPTIONAL) Enter a network mask in /prex format (/x) or A.B.C.D. The mask, when
specied in A.B.C.D format, may be either contiguous or non-contiguous.
244 Access Control Lists (ACL)