CLI Guide
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 – assigns a lter to deny IP trac.
deny tcp – assigns a deny lter for TCP trac.
deny tcp (for IPv6 ACLs)
Congure 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 /prex format (/x) or A.B.C.D. The mask, when specied 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)