Basics of TCP/IP Networking
This article is about the basics of TCP/IP networking.
Tcp and Ip are what let networks talk to each other. Tcp is the rules and Ip is
the addressing. You need both working to have a functional network.
Computers work with binary numbers the easiest. So, Ip uses binary numbers for
addressing. Binary numbers include either 0 or 1 as digits. The size of the
number depends on the digits allowed. Binary is good at working with logical operations.
Logical operations are such things as "and", "or", and "not". An AND operation compares two binary values. If bothy of these values are 1 then it is true. An OR operation is similar but if either of the values are 1 then it is true. NOT changes the value of an operation to the opposite.
Next thing I want to talk about is IP addresses. There can be many different devices on a network. These devices can be just about anything from a printer to a microwave. These devices have to be identified so the network knows what to do.This is done by giving devices IP addresses. It is like apartment numbers in a big apartment building. An IP address consists of a network address and a host address.
Speaking of addresses, subnetting lets you use your addresses more efficiently. You are given a range of addresses to use when you get your initial IP address. If you segment your network to make it smaller to just what you use, this speeds up network performance. That is the purpose of subnetting. If you are a network administrator and in charge of a large company network, this is something you might have to deal with. You won't if you just have a small home network.
Any machine with a direct connection to the internet will have a unique address. Not everyone has a direct connection either. If you are behind a firewall then you will have in indirect connection. Your IP address will not be unique at this point. Most home networks use this configuration. This saves space and makes it easier to deal with.
If you use a firewall, then it probably uses NAT or network address translation.
It does this to hide the IP addresses from the public. As network packets leave
the firewall to the outside world, the internal IP addresses get translated to
the public address. The reverse is true of traffic coming from the outside
world.
DHCP, or dynamic host configuration protocol, configures your IP addresses for
you. It does this to let each device have a unique identifier. DHCP is installed
on one of your servers. The devices on your network talk to it and get
configured by it. This is how they get their unique IP addresses. If you did not
have DHCP, you would have to do this all by yourself. Small networks can do this
without a problem. In fact, servers and printers will usually have static IP
addresses. If you have a large network then you might give two different devices
the same address. This will cause problems quickly. Using DHCP prevents this.
As I mentioned before, DHCP will need to be on a server. Most server operating
systems have it as a feature anyway so we usually do not have to worry about
installing it. It is really just activating the feature.
DHCP scopes are just the range of addresses that DHCP has permission to work
with. You can set whatever scope you want. This is done differently in both
Windows and Linux but it means the same thing. You can also exclude certain
addresses or ranges within a certain scope. If you do this, DHCP will not give
out any of those addresses. This is useful if you have your printers on a
certain range and do not want those addresses to ever be given out.
The next topic I want to talk about is DNS. It stands for domain name system. It
is the mechanism that lets us use names instead of having to remember IP
addresses for every website you go to. To function, DNS uses domains. Under each
domain are the networks that are created by people. In each network there are
desktops, laptops, and printers. Each of these has its own distinct name made up
of the network and domain.
You will configure your server operating system with the DNS server you want to
use. This is different in Windows than it is in Linux but the principles are the
same. Then, when setting up your clients, you configure them to point to the DNS
located on your server.