Understanding TCP/IP
TCP/IP is the language
of the Internet, and is a
T
CP/IP (Transmission Control Protocol/Internet Protocol, or IP for short)
is the name given to a whole group of related protocols which comprise
the language of the Internet. Although there's nothing intrinsically better
about TCP/IP relative to better known LAN protocols such as Novell's IPX/SPX
cross platform protocol
or Microsoft's NetBEUI, it is rapidly becoming the de facto standard network
protocol for one simple reason the Internet.
despite its long
IP has gone through multiple versions since its original development. Currently,
association with Unix.
version 4 is by far the most widely used. However, there are later revisions.
Because of the rise in
Version 5 was never released, but its successor, once termed IPng (IP next
generation) but now ratified as IPv6, is out there and will gradually replace the
importance of the
current version (IPv4). This is undoubtedly going to be a tremendous pain for
Internet and
everyone involved, as the changes are major, but it will be necessary. IPv4 uses
32 bit addresses, allowing for a theoretical maximum of 4,294,967,295 unique
connectivity, it makes
addresses. In October 1999 the number of human beings passed six billion, and
the number of computers probably isn't too far behind and one day, they might
sense to consider using
all need to be connected.
IP in your intranet or
Clearly, 32 bit addresses won't be enough for very much longer, and this is the
LAN or at least being
driving reason for IPv6, which uses 128 bit addresses, allowing a startlingly vast
range of addresses: approximately 3.402824 x 10
38
. Estimates vary, but this should
aware of its implications.
be rather more than enough to allow every atom in the universe a unique IP
address. Although the other changes between these versions are mostly minor
By Liam Proven
and internal, the two protocols are not directly compatible; though they can share
IT Journalist
a network, IPv4 nodes and IPv6 nodes cannot directly communicate. Changing
from one to the other is therefore a substantial task, and the transition will cause
a comparable amount of trouble to the Y2K bug and will come only a few years
later. Right now, however, it is IPv4 that we must deal with, and that's what we
will look at here.
IP And Your LAN
Because the Internet is becoming so widespread as to be nearly universal, it is also
becoming more useful in business. As more companies get connected, the viabil
ity of the Internet for business to business communication increases. Similarly,
as more people use the Internet for personal or leisure purposes, its value as a
way of reaching customers grows. Finally, even if neither of these appeals, the
standardisation on Internet communications protocols and the fact that much
Internet software is free means that, even for purely internal systems, businesses
can reap significant cost savings by using Internet technologies.
As the Internet runs over IP, so do Internet based applications. Whereas proprie
tary email systems such as Microsoft Mail use other, protocol independent means
of communication (such as shared file systems), Internet based email programs
communicate over IP, so client machines need an IP based connection to the
Address Class
First Octet
Network Mask
A
1. to 127.
255.0.0.0
B
128. to 191.
255.255.0.0
C
192. to 233.
255.255.255.0
D
224. to 239.
None
Figure 1 Summary of Internet address classes.
Issue 126:January 2001
PC Network Advisor
File: T1838.1
page 9
Tutorial:Internet
www.pcnetworkadvisor.com
Next page >
New! The best sites for quality inkjet printer cartridges and the best sites for cheap inkjet cartridges