REB175P
USER’S GUIDE
95
Port Filtering
Port Filtering is only available in Firewall Range Extender
mode.
Port Filtering is a security measure that prevents users from
using specific ports for reasons other than what those ports
were originally intended for. For example, TCP port 21 is traditionally used for FTP. However, there is nothing
stopping a user from using port 21 for purposes other than FTP access. By enabling Port Filtering on TCP port
21, only FTP communications would be allowed. No other types of communication would be allowed on this
port.
Hackers may sometimes scan for all open ports on your network as a method of hacking into your network.
Port Filtering and other firewall features help to prevent this from happening.
To set up Port Filtering, select a range of ports you wish to filter. If you are trying to filter a single port, enter
the port number twice (For example, Port 21: 21 – 21). Select the Protocol of the port you are filtering. If you
do not know what protocol you wish to filter, select “Both”.
