Dummies, Wireless

Chapter 4: Planning a Wireless Home Network
DHCP — and in most cases NAT — servers and typically include
switches. In fact, the AP and the modem can also include a built-in
router that provides instant Internet sharing all in one device.
As we mention earlier in the chapter, nearly all APs now available for home
networks have a built-in broadband router.
Read through Chapter 10 for details on how to set up Internet sharing.
Given the fact that you can buy a router (either as part of an access point
or a separate router) for well under $60 these days (and prices continue to
plummet), we think it’s false economy to skip the router and use a softwarebased,
Internet connection sharing setup. In our minds, at least, the advantage
of the software-based approach (very slightly less money up front) is
outweighed by the disadvantages (requiring the PC to always be on, lower
reliability, lower performance, and a much bigger electric bill each month).
Both software-based, Internet connection sharing and cable or DSL routers
enable all the computers in your home network to share the same network
(IP) address on the Internet. This capability uses network address translation
(NAT). A device that uses the NAT feature is often called a NAT router. The
NAT feature communicates with each computer on the network by using a
private IP address assigned to that local computer, but the router uses a
single public IP address in data it sends to computers on the Internet. In
other words, no matter how many computers you have in your house sharing
the Internet, they look like only one computer to all the other computers on
the Internet.
Whenever your computer is connected to the Internet, beware the potential
that some malicious hacker may try to attack your computer with a virus or
try to break into your computer to trash your hard drive or steal your personal
information. Because NAT technology hides your computer behind the
NAT server, it adds a measure of protection against hackers, but you shouldn’t
rely on it solely for protection against malicious users. You should also consider
purchasing full-featured firewall software that actively looks for and
blocks hacking attempts, unless the AP or router you purchase provides that
added protection. We talk about these items in more detail in Chapter 9.
As we recommend in the “Choosing an access point,” section earlier in this section,
try to choose an AP that also performs several other networkoriented
services. Figure 4-4 depicts a wireless home network using an AP that
also provides DHCP, NAT, a print server, and switched hub functions in a single
stand-alone unit. This wireless Internet gateway device then connects to the
DSL or cable modem, which in turn connects to the Internet. Such a configuration
provides you with connectivity, sharing, and a little peace of mind, too.
If you already have a wired network and have purchased a cable or DSL router
Internet gateway device without the AP function, you don’t have to replace
the existing device. Just purchase a wireless access point. Figure 4-5 depicts
89