Game Development Reference
In-Depth Information
by a device I have hooked up to my network. Whenever one of my computers boots,
it is assigned a host ID automatically. The device that hands out the addresses is
called a Dynamic Host Configuration Protocol (DHCP) server and is exactly what
you find on most wireless routers. If I didn
'
t have one of these devices, I
'
d have to
assign each of my computers a unique IP address. What a hassle.
There are some special IP addresses you should know about, as well as some special
network IDs (see Table 19.2).
Table 19.2 Special IP Addresses and Network IDs
Address
Description
127.0.0.1
Called the loopback address and always refers to
your computer. It is also called the localhost.
127.x.x.x
Loopback subnet; this network ID is used for
diagnostics.
255.255.255.255
This IP address refers to all hosts on the local
network.
10.x.x.x
172.(16-31).x.x
192.168.x.x
Private networks; any address with these network
IDs is considered on the local network, and not on
the Internet at large. Use these addresses for your
home or local company network if they don
'
t
need to be visible on the Internet.
When you browse the Web, your Web browser program attaches to another com-
puter on the Internet, downloads a Web page and anything attached to it, and ren-
ders the Web page so you can see it. But when you browse the Web, you don
tgoto
http://207.46.131.43, do you? If you put this specific address in your browser, you
'
'
ll
be rewarded with Microsoft
'
s Web page.
Luckily for us, there
s an easier way to find computers on the Internet. Clearly,
www.microsoft.com
is easier to read and remember than 207.46.131.43. The
designers of the Internet designed a distributed database called the Domain Name
System, or DNS.
This system is structured like a hierarchical tree. The first level of the tree consists of
the top-level domains (TLD), some of which are listed in Table 19.3.
TLDs are also available for foreign countries to use, although they are generally used
in as free and open a manner as the rest of the Internet. For example, .uk is used for
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