Administrator Guide

• permit — congure a permit lter.
deny (for Extended IP ACLs)
Congure a lter that drops IP packets meeting the lter criteria.
Syntax
deny {ip | ip-protocol-number} {source mask | any | host ip-address}
{destination mask | any | host ip-address} [ttl operator] [count [byte]] [dscp
value] [order] [monitor] [fragments] [log [interval minutes] [threshold-in-msgs
[count]] [monitor]
To remove this lter, you have two choices:
• Use the no seq sequence-number command if you know the lter’s sequence number.
• Use the no deny {ip | ip-protocol-number} {source mask | any | host ip-address}
{destination mask | any | host ip-address} command.
Parameters
ttl Enter the keyword ttl to deny a packet based on the time to live value. The range is
from 1 to 255.
operator Enter one of the following logical operand:
• eq(equal to) — matches packets that contain a ttl value that is equal to the specied
ttl value.
• neq(not equal to) — matches packets that contain a ttl value that is not equal to the
specied ttl value.
•
gt(greater than) — matches packets that contain a ttl value that is greater than the
specied ttl value.
• lt (less than) — matches packets that contain a ttl value that is less than the
specied ttl value.
• range(inclusive range of values) — matches packets that contain a ttl value that
falls between the specied range of ttl values.
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 time interval range is from 1 to 10 minutes.
monitor (OPTIONAL) Enter the keyword monitor when the rule is describing the trac that you
want to monitor and the ACL in which you are creating the rule is applied to the
monitored interface.
Defaults
By default, 10 ACL logs are generated if you do not specify the threshold explicitly.
The default frequency at which ACL logs are generated is ve minutes. By default, ow-based monitoring is not
enabled.
Command Modes CONFIGURATION-EXTENDED-ACCESS-LIST
Access Control Lists (ACL) 275