Users Guide

8.2.1.0 Introduced on the E-Series TeraScale.
7.8.1.0 Introduced on the C-Series.
7.4.1.0 Introduced on the E-Series TeraScale Added the monitor option.
deny tcp
Configure a filter that drops TCP packets that match the filter 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] [monitor]
To remove this filter, you have two choices:
● Use the no seq sequence-number command syntax if you know the filter’s sequence number
● Use the no deny tcp {source address mask | any | host ipv6-address}
{destination address | any | host ipv6-address} command
Parameters
source address Enter the IPv6 address of the network or host from which the packets were sent in
the x:x:x:x::x format followed by the prefix length in the /x format. The range is /0
to /128. The :: notation specifies successive hexadecimal fields of zero.
mask Enter a network mask in /prefix format (/x).
any Enter the keyword any to specify that all routes are subject to the filter.
host ipv6-
address
Enter the keyword host followed by the IPv6 address of the host in the x:x:x:x::x
format. The :: notation specifies successive hexadecimal fields of zero.
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 parameter).
port port
Enter the application layer port number. Enter two port numbers if using the range
logical operand. The range is 0 to 65535.
The following list includes some common TCP port numbers:
● 23 = Telnet
● 20 and 21 = FTP
● 25 = SMTP
● 169 = SNMP
destination
address
Enter the IPv6 address of the network or host to which the packets are sent in the
x:x:x:x::x format followed by the prefix length in the /x format. The range is /0
to /128. The :: notation specifies successive hexadecimal fields of zero.
bit Enter a flag or combination of bits:
● ack: acknowledgement field
● fin: finish (no more data from the user)
● psh: push function
● rst: reset the connection
● syn: synchronize sequence numbers
● urg: urgent field
Access Control Lists (ACL) 195