Dummies, Wireless

Chapter 11: Gaming Over a Wireless Home Network
Port forwarding effectively opens a hole in your firewall that not only allows
legitimate game or other application data through but may also let the bad
guys in. Set up port forwarding only when you have to, and keep an eye on
the logs. (Your router should keep a log of whom it lets in — check the manual
to see how to find and read this log.) We also recommend that you consider
using personal firewall software on your networked PCs (we like ZoneAlarm,
www.zonelabs.com) and keep your antivirus software up to date.
Some routers let you set up application-triggered port forwarding (sometimes
just called port triggering), which basically allows your router to look for certain
signals coming from an application on your computer (the triggers) and
then enable port forwarding. This option is more secure because when the
program that requires port forwarding (your game, in this case) isn’t running,
your ports are closed. They open only when the game (or other application)
requires them to be open.
When you set up port forwarding on your router, you’re selecting specific
ports (ports are subsegments of an IP address — a computer with a specific
IP address uses different numbered ports to connect different applications
to the network) and sending all incoming requests using those ports to a
specific computer or device on your network. When you get involved in setting
up port forwarding, you notice two kinds of ports: TCP (Transmission Control
Protocol) and UDP (User Datagram Protocol). These names relate to the two
primary ways in which data is carried on the Internet, and you may have to set
up port forwarding for both TCP and UDP ports, depending on the application.
Every router or access point will have its own unique system for configuring
port forwarding. Generally speaking, you find the port forwarding section of
the configuration program and simply type into a text box on the screen the
port numbers you want to open. For example, Figure 11-2 shows port forwarding
being configured on a NETGEAR WPN824 router/access point.
As we mention earlier in this chapter, ports are assigned specific numbers. To
get some gaming applications to work properly, you need to open (assign)
port forwarding for a big range of port numbers. The best way to find out
which ports need to be opened is to read the manual or search the Web page
of the game software vendor. You can also find a relatively comprehensive list
online at practicallynetworked.com/sharing/app_port_list.htm.
If your router is UPnP enabled (Universal Plug and Play, a system developed
by Microsoft and others that, among other things, automatically configures
port forwarding for you) and the PC game you’re using uses Microsoft DirectX
gaming, the router and the game should be able to talk to each other and
automatically set up the appropriate port forwarding. Just make sure that
you enable UPnP in your router’s configuration system. Usually you simply
click a check box in the router’s configuration program.
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