January 19th, 2003, 09:54 PM
Network Terms Simplified
It has been suggested that I write a tutorial on basic fundamentals of
networking. Networking of course, is how computers communicate with each
other, share files, hardware, etc. This tutorial is intended for those who
can network their computers if they know what the terms mean. I cannot get
OS (operating system, i.e. windows, linux etc) specific in this one, since
it is intended for you the networker, to grasp certain terms that are
sometimes bothersome. So here goes:
1. MAC Address - This is the address that is specific to your computers
hardware. MAC stands for Media Access Control. Think of this as your
"Physical address" Address meaning where your computer is located on the
2. IP Address -Internet Protocol; This numeric address specifies your
computers location on
the network. It can change very easily. For instance say you are laying
out the ground work for a new network. You want the addresses to be
chronological, you have say 3 computers. You wouldnt worry about the mac
addresses for they are machine specific.
Computer A ====network_cable========ComputerB============ComptuterC
192.168.1.100 192.168.1.101 192.168.1.102
IP Address^ IP Address^ IP Address^
Therefore computer A has the address 192.168.1.100 computer B has the
address 192.168.1.101 and computer C has the address 192.168.1.102
These fall in order and are unique to themselves. The "192" in
192.168.xxx.xxx is a certain area of ip addresses. It is usually
recommended when networking you DHCP your addresses, meaning have a DHCP
server automatically assign internal ips.
The basic different between internal and external ips is that internal is
what is on your network (e.g. 192.168.xxx.xxx) while an external is what
ip you are given when you connect to the internet.
3. DHCP - Dynamic Host Configuration Protocol. It allows you the network
admistrator to not have to edit each computers address on your network.
What it does is assign each computers addresses automatically. While this
doesnt seem too helpful on a small network, it is a great tool when you
have a very LARGE network.
4. ARP - Address Resolution Protocol. This is generally not used by a home
user or even a small business (manually that is) but what it does is maps
IP addresses to MAC addresses.
5. A router is normally a device that decides where the packets will go
(forwarding) on your network. Although the router can sometimes be
software installed on a computer, for instance SMOOTHWALL, its normally a
piece of firmware that has a power plugin, led lights for confirmation,
and rj-45 connector(s) for you to plug your network cable in. It is a
great tool to use if you have several computers on a network that you want
internet distributed upon as well as more security. A NAT router (Network
Address Translation) is generally the most secure of all. Its is often
part of a firewall built within the router, or even by itself. It maps the
routers internal address's separate from the externals, keeping nasty data
out without a test.
6. Firewall - A firewall is a program or a set of programs that protect
certain things or resources of your network from other networks. What a
firewall does in general, is look over each packet (piece of data
including headers) and determine whether it should forward it or not. Most
modern firewall programs provide information to you when it is confused of
whether passing the packet(s) along or not. Firewalls are normally
incorporated with routers or network devices of some sort.