3Com 3CRWE754G72-A - Manual (Page 53)

Firewall 53
4 Click Apply.
Virtual Servers Figure 41 Virtual Servers Screen
This function will allow you to route external (Internet) calls for services
such as a web server (port 80), FTP server (Port 21), or other applications
through your Router to your internal network. Since your internal
computers are protected by a firewall, machines from the Internet cannot
get to them because they cannot be 'seen'.
If you need to configure the Virtual Server function for a specific
application, you will need to contact the application vendor to find out
which port settings you need.
To manually enter settings:
1 Enter the IP address in the space provided for the internal machine.
2 Enter the port type (TCP, UDP, or both TCP and UDP).
3 Specify the Public port that will be seen by clients on the Internet, and the
LAN port which the traffic will be routed to.
4 You can enable or disable each Virtual Server entry by checking or
unchecking the appropriate Enable checkbox.
5 Click Apply to save the changes for each Virtual Server entry.