Netopia R2121 User Reference Manual page 170

14-8 User's Reference Guide
Port numbers
A filter can also match a packet's port number attributes, but only if the filter's protocol type is set to TCP or
UDP, since only those protocols use port numbers. The filter can be configured to match the following:
The source port number (the port on the sending host that originated the packet)
The destination port number (the port on the receiving host that the packet is destined for)
By matching on a port number, a filter can be applied to selected TCP or UDP services, such as Telnet, FTP, and
World Wide Web. The tables below show a few common services and their associated port numbers..
Internet service
FTP
Telnet
SMTP (mail)
Gopher
Internet service
Who Is
World Wide Web
SNMP
TFTP
Port number comparisons
A filter can also use a comparison option to evaluate a packet's source or destination port number. The
comparison options are:
No Compare: No comparison of the port number specified in the filter with the packet's port number.
Not Equal To: For the filter to match, the packet's port number cannot equal the port number specified in the
filter.
Less Than: For the filter to match, the packet's port number must be less than the port number specified in the
filter.
Less Than or Equal: For the filter to match, the packet's port number must be less than or equal to the port
number specified in the filter.
Equal: For the filter to match, the packet's port number must equal the port number specified in the filter.
Greater Than: For the filter to match, the packet's port number must be greater than the port number specified
in the filter.
TCP port Internet service
20/21 Finger
23 World Wide Web
25 News
70 rlogin
UDP port Internet service
43 AppleTalk Routing
Maintenance (at-rtmp)
80 AppleTalk Name Binding
(at-nbp)
161 AURP (AppleTalk)
69 who
TCP port
79
80
144
513
UDP port
202
202
387
513