LOOQS MeeBox Router - Manual (Page 51)

Page 51
User Guide LOOQS MeeBox Router
Forwarding incoming connections
Introduction to port forwarding
Like most other routers, your MeeBox by default blocks all incoming communication
attempts from outside computers to computers and devices on the server’s local network,
unless the incoming communications are in response to an outgoing request from the
same computer. (Outgoing connections are not blocked at all.) For example, when you
request a web page on the Internet by entering a URL in your browser, your MeeBox’s
built-in router ―remembers‖ which computer made the outgoing request and to what web
server the request was made. Then, when the web server sends the requested page, the
router passes the incoming data on to the requesting computer. If a computer on the
Internet attempts to connect to a local computer without the local computer having
initiated communications with it, the router normally blocks the attempt. This is to protect
your network against unwanted intrusion.
There may be times when you want specific kinds of incoming connections to be
permitted through to your network—to not be blocked by the router—even if they are not
in response to an outgoing request. One example involves the popular peer-to-peer file-
sharing application, eMule. For eMule to work best, other computers (peers) on the eMule
network must be able to connect to your computer running eMule, although your
computer does not initiate communications with them. Blocking these incoming
connections causes both download and upload speeds in eMule to be reduced.
Port forwarding is provided by the router as a way to accommodate exceptions to the
general policy of blocking all unsolicited incoming connections. Port forwarding takes
advantage of the fact that, for any given Internet application, incoming connections are
almost always addressed to certain specific ports on the destination computer. For
example, requests for web pages are almost always addressed to the web server’s port 80,
and the web server is said to ―listen‖ for incoming connections on that port. (It may be
useful to think of ports as being like individual mailboxes in an apartment building, and
think of the building as being like a computer. For a letter to reach its destination, you must
specify both the building’s address and the apartment number.)
If you want to allow incoming connections to a program running on your computer—
eMule, for example—configure the router to forward connections on the port (or ports) on