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APPENDIX B: Lynx L-510 terms
What is a firewall?
A firewall is protection between the Internet and your local network. It acts
similarly to the firewall in your car, protecting the interior of the car from the
engine. Your car's firewall has very small opening that allow desired
connections from the engine into the cabin (gas pedal connection, etc), but if
something happens to your engine, you are protected.
The firewall in the Lynx L-510 is very similar. Only the desired connections
that you allow are passed through the firewall. These connections are
normally originating from the local network; such as web browsing, checking
your email, downloading a file, and playing a game. However, in some cases,
you can allow incoming connections so that you can run programs like a web
server.
What is NAT?
NAT stands for Network Address Translation. Another name for it is
Connection Sharing. What does this mean? Your ISP provides you with a
single network address for you to access the Internet through. However, you
may have several machines on your local network that want to access the
Internet at the same time. The Lynx L-510 provides NAT functionality that
converts your local network addresses to the single network address
provided by your ISP. It keeps track of all these connections and makes sure
that the correct information gets to the correct local machine.
Occasionally, there are certain programs that don't work well through NAT.
Some games, and some specialty applications have a bit of trouble. The Lynx
L-510 contains special functionality to handle the vast majority of these
troublesome programs and games. NAT does cause problems when you want
to run a SERVER though. When running a server, please see the DMZ section
below.
What is a DMZ?
DMZ really stands for Demilitarized Zone. It is a way of separating out part
of your local network so that is more open to the Internet. Suppose that you
want to run a web-server, or a game server. Normal servers like these are
blocked from working by the NAT functionality. The solution is to "isolate"
