Administrator Guide

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).
deny icmp (for Extended IP ACLs)
To drop all or specific internet control message protocol (ICMP) messages, configure a filter.
NOTE: Only the options that have been newly introduced in Release 9.3(0.0) and Release 9.4(0.0) are described here.
For a complete description on all of the keywords and variables that are available with this command, refer the topic of
this command discussed earlier in this guide.
Syntax
deny icmp {source mask | any | host ip-address} {destination mask | any | host
ip-address} [ttl operator] [dscp] [message-type] [count [byte]] [order]
[fragments] [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 icmp {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 specified
ttl value.
• neq(not equal to) — matches packets that contain a ttl value that is not equal to the
specified ttl value.
•
gt(greater than) — matches packets that contain a ttl value that is greater than the
specified ttl value.
• lt (less than) — matches packets that contain a ttl value that is less than the
specified ttl value.
• range(inclusive range of values) — matches packets that contain a ttl value that
falls between the specified 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 traffic 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 five minutes. By default, flow-based monitoring is not
enabled.
Command Modes CONFIGURATION-EXTENDED-ACCESS-LIST
Command History
This guide is platform-specific. For command information about other platforms, see the relevant Dell EMC
Networking OS Command Line Reference Guide.
Version Description
9.12(0.0) Introduced the ttl parameter.
268 Access Control Lists (ACL)