Concept Guide

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).
The order option is relevant in the context of the Policy QoS feature only. For more information, refer to the
Quality of Service chapter of the Dell Networking OS Conguration Guide.
The monitor option is relevant in the context of ow-based monitoring only. For more information, refer to the
Port Monitoring.
When you use the log option, the CP processor logs details 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 (ARP and Ether-type) to Layer 2 interfaces only.
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.
deny icmp
To drop all or specic internet control message protocol (ICMP) messages, congure a lter.
Syntax
deny icmp {source mask | any | host ip-address} {destination mask | any | host
ip-address} [dscp] [count [byte]] [order] [fragments][threshold-in-msgs]
[count]]
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 icmp {source mask | any | host ip-address} {destination mask |
any | host ip-address} command.
Parameters
source Enter the IP address of the network or host from which the packets were sent.
mask 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.
any Enter the keyword any to specify that all routes are subject to the lter.
host ip-address Enter the keyword host then the IP address to specify a host IP address.
destination Enter the IP address of the network or host to which the packets are sent.
dscp Enter this keyword dscp to deny a packet based on the DSCP value. The range is from 0
to 63.
count (OPTIONAL) Enter the keyword count to count packets processed by the lter.
byte (OPTIONAL) Enter the keyword byte to count bytes processed by the lter.
order (OPTIONAL) Enter the keyword order to specify the QoS priority for the ACL entry.
The range is from 0 to 254 (where 0 is the highest priority and 254 is the lowest; lower
order numbers have a higher priority) If you did not use the keyword order, the ACLs
have the lowest order by default (255).
Access Control Lists (ACL) 221