Users Guide
Command History
This guide is platform-specic. For command information about other platforms, see the relevant Dell Networking 
OS Command Line Reference Guide.
Version Description
9.8(1.0) Introduced on the Z9100–ON.
9.8(0.0P5) Introduced on the S4048-ON.
9.8(0.0P2) Introduced on the S3048-ON.
9.7(0.0) Introduced on the S6000–ON.
9.4(0.0) Added support for ow-based monitoring on the S4810, S4820T, S6000, and Z9000 
platforms.
9.3(0.0) Added support for logging of ACLs on the S4810, S4820T, and Z9000 platforms.
Usage Information
When the congured maximum threshold is exceeded, generation of logs is stopped. When the interval at which 
ACL logs are congured 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 congured 
threshold is exceeded, it is re-enabled for this new interval.
If ACL logging is stopped because the congured 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 congure 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, trac 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 specied trac 
instead all trac on the interface. This feature is particularly useful when looking for malicious trac. It is available 
for Layer 2 and Layer 3 ingress and egress trac. You may specify trac 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
• deny — congure a lter to drop packets.
• permit — congure a lter to forward packets.
deny tcp (for Extended IP ACLs)
Congure a lter that drops transmission control protocol (TCP) packets meeting the lter criteria.
Syntax
deny tcp {source mask | any | host ip-address} [bit] [operator port [port]] 
{destination mask | any | host ip-address} [dscp] [bit] [operator port [port]] 
[count [byte]] [order] [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 tcp {source mask | any | host ip-address} {destination mask | 
any | host ip-address} command.
272 Access Control Lists (ACL)










