User`s guide

Internet Features
47
Virtual Servers
This feature allows you to make Servers on your LAN accessible to Internet users. Normally,
Internet users would not be able to access a server on your LAN because:
• Your Server does not have a valid external IP Address.
• Attempts to connect to devices on your LAN are blocked by the firewall in this device.
The "Virtual Server" feature solves these problems and allows Internet users to connect to your
servers, as illustrated below.
Figure 32: Virtual Servers
IP Address seen by Internet Users
Note that, in this illustration, both Internet users are connecting to the same IP Address, but
using different protocols.
To Internet users, all virtual Servers on your LAN have the same IP Address.
This IP Address is allocated by your ISP.
This address should be static, rather than dynamic, to make it easier for Internet users to
connect to your Servers.
However, you can use the DDNS (Dynamic DNS) feature to allow users to connect to your
Virtual Servers using a URL, instead of an IP Address.
TW100-BRF114 User’s Guide
48
Virtual Servers Screen
The Virtual Servers screen is reached by the Virtual Servers link on the Internet menu. An
example screen is shown below.
Figure 33: Virtual Servers Screen
This screen lists a number of pre-defined Servers, and allows you to define your own Servers.
Details of the selected Server are shown in the "Properties" area.
Data - Virtual Servers Screen
Servers
Servers
This lists a number of pre-defined Servers, plus any Servers you
have defined. Details of the selected Server are shown in the
"Properties" area.
Properties
Enable
Use this to Enable or Disable support for this Server, as required.
• If Enabled, any incoming connections will be forwarded to the
selected PC.
• If Disabled, any incoming connection attempts will be blocked.
PC (Server)
Select the PC for this Server. The PC must be running the appro-
priate Server software.
Protocol
Select the protocol (TCP or UDP) used by the Server.
Internal Port No.
Enter the port number which the Server software is configured to
use.
External Port No.
The port number used by Internet users when connecting to the
Server. This is normally the same as the Internal Port Number. If it
is different, this device will perform a "mapping" or "translation"
function, allowing the server to use one port address, while clients
use a different port address.