CLI Guide

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).
Related Commands
deny – assigns a lter to deny IP trac.
deny tcp – assigns a deny lter for TCP trac.
deny tcp (for IPv6 ACLs)
Congure a lter that drops TCP packets that match the lter criteria.
Syntax
deny tcp {source address mask | any | host ipv6-address} [operator port [port]]
{destination address | any | host ipv6-address} [bit] [operator port [port]]
[count [byte]] [log [interval minutes] [threshold-in-msgs [count]] [monitor]
To remove this lter, you have two choices:
Use the no seq sequence-number command syntax if you know the lter’s sequence number
Use the no deny tcp {source address mask | any | host ipv6-address}
{destination address | any | host ipv6-address} command
Parameters
source Enter the IP address of the network or host from which the packets are 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 ipv6–address Enter the keyword host then the IPv6 address to specify a host IP address.
operator (OPTIONAL) Enter one of the following logical operand:
eq = equal to
neq = not equal to
gt = greater than
lt = less than
range = inclusive range of ports (you must specify two ports for the port command)
port Enter the application layer port number. Enter two port numbers if using the range logical
operand. The range is from 0 to 65535. The following list includes some common TCP
port numbers:
23 = Telnet
20 and 21= FTP
258 Access Control Lists (ACL)