A Fire Door relay is a link between your private network and the Internet. Each relay connects a TCP or UDP port on your private network to a similar port on another machine.
You will not normally need to add relays to Fire Door in order to access the World-Wide-Web because the internal WWW proxy will usually do all all of the hard work. However, there may be some systems which require a special configuration in which case a relay is the way to go.
Note that Fire Door has a special relay for the "SOCKS" protocol on port 1080. This protocol was specifically design for firewalls, and allows SOCKS enabled applications to access any Internet resource. Netscape Navigator is an example of a SOCKS enabled application.
Port 1082 is normally used for the Fire Door HTTP port and the WWW proxy.
Three pieces of information are required to set up a relay:
For example, to set up a World Wide Web relay from your Fire Door machine to your service provider, you might have the following:
To add this relay to your configuration, go to the Add New Relay form and type the service name and the transport type separated by a "/" character into the field labeled "New relay service". For the example above, the string entered would be "www/tcp" or "80/tcp".
The name or IP number of the destination host machine should then be entered into the field labeled "New relay destination".
Once these values are entered, click the button labelled "Accept". A new page will be displayed confirming that the relay agent has been added. Use the "Back" button on your Internet browser to return to the Relay Agent page, which should appear with the new relay agent in the list of Currently Active Relays.
NOTE: - the use of strings for specifying relay service ports, rather than explicit port numbers, is encouraged.
By default, the port number used on the relay destination will be the same as the port specified for the service name. This can be changed by specifiying a port number or service name after the relay destination separated by a colon (":") character.
For example, to map port 2000 on your Fire Door host to the "www" port of the machine called "another.isp.com", you could use the values "2000/tcp" and "another.isp.com:www" Note that you can also override the desination IP address of a relay depending upon the dialup host in use - this is especially useful for DNS relays as each dialup host will probably use a different name server.
See also Relay Overrides
A Fire Door relay normally connects a service to a single host. For example, a normal relay will connect the Telnet port (23/tcp) on the Fire Door host to the Telnet port on another machine, allowing any user on your private network to Telnet to that machine as though it were on the local network.
For some protocols however, it is useful to allow a single port to connect to any number of hosts. By specifying the relay destination as the special string "(ASK)", Fire Door will prompt the user connecting to that port, eg via Telnet, to for the name of the host to connect when they connect to that port.
Removing a relay agent can be done by deleting the contents of the relay destination field in the correct entry of the Currently Active Relays list. After pressing the "Accept" button and returning to the Relay Agent page, the relay agent will have been removed.
If you need to change the relay destination of a relay agent, enter the new value into the correct field of the Currently Active Relays list and then press the "Accept" button. This will update the relay agent configuration with the new information.
NOTE: It is not possible to change the relay service field of a relay in the Currently Active Relays list. To change the port and protocol of a relay, first remove the agent and then add it again with the new paramaters.