Go to the previous, next section.
Every single machine on the Internet has a unique address,(2) called its Internet number or IP Address. It's
actually a 32-bit number, but is most commonly represented as four
numbers joined by periods (`.'), like 147.31.254.130.
This is sometimes also called a dotted quad; there are literally
thousands of different possible dotted quads. The ARPAnet (the mother
to today's Internet) originally only had the capacity to have up to
256 systems on it because of the way each system was addressed. In
the early eighties, it became clear that things would fast outgrow
such a small limit; the 32-bit addressing method was born, freeing
thousands of host numbers.
Each piece of an Internet address (like 192) is called an
"octet," representing one of four sets of eight bits. The first two
or three pieces (e.g. 192.55.239) represent the network that a
system is on, called its subnet. For example, all of the
computers for Wesleyan University are in the subnet 129.133.
They can have numbers like 129.133.10.10, 129.133.230.19,
up to 65 thousand possible combinations (possible computers).
invisible.xbm
invisible.xbm
IP addresses and domain names aren't assigned arbitrarily--that would
lead to unbelievable confusion. An application must be filed with the
Network Information Center (NIC), either electronically (to
hostmaster@nic.ddn.mil) or via regular mail.
Go to the previous, next section.