Chapter 3: Networking and Advanced Settings
Chapter 3
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Forwarding Web Page (Fig. 22)
For LAN <=> WAN communications, the gateway normally only
allows you to originate an IP connection with a PC on the
WAN; it will ignore attempts of the WAN PC to originate a
connection onto your PC. This protects you from malicious
attacks from outsiders. However, sometimes you may wish for
anyone outside to be able to originate a connection to a
particular PC on your LAN if the destination port (application)
matches one you specify.
This page allows you to specify up to 10 such rules. For
example, to specify that outsiders should have access to an FTP
server you have running at 192.168.0.5, create a rule with that
address and Start Port = 20 and End Port = 21 (FTP port ranges)
and Protocol = TCP (FTP runs over TCP vs the other transport
protocol, UDP), and click Apply. This will cause inbound packets
that match to be forwarded to that PC rather than blocked. As
these connections are not tracked, no entry is made for them in
the Connection Table. The same IP address can be entered
multiple times with different ports.
Port Triggers Web Page (Fig. 23)
Some Internet activities, such as interactive gaming, require
that a PC on the WAN side of your gateway be able to originate
connections during the game with your game playing PC on the
LAN side. You could use the Advanced...Forwarding page to
construct a forwarding rule during the game, and then remove
it afterwards (to restore full protection to your LAN PC) to
facilitate this. Port Triggering is an elegant mechanism that
does this work for you, each time you play the game.
Port Triggering works as follows. Imagine you want to play a
particular game with PCs somewhere on the Internet. You make
a one time effort to set up a Port Trigger for that game, by
entering into Trigger Range the range of destination ports your
game will be sending to, and entering into Target Range the
Fig. 22
Fig. 23
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