Here you will learn about ip address network introduction and general overview of routing, subnet mask, subnetting, data communication. IP address is an identifier for a computer or device on a TCP/IP network and Internet. Networks that use the TCP/IP protocols route traffic based on the IP address of the destination computer or network device. The format of the IP address is 32 bits 4 octets 4 bytes such as 100.100.10.1, 210.100.22.30, 1.10.1.2 these are the examples of the IP address. The format is a 32-bit numeric value written as four numbers and separated by periods.

Each number in the IP address can be between 0 and 255. In your private network, you can assign unique IP address randomly. However, when you want to connect your private network to the Public network such as Internet then you must need a registered IP address to communicate on the internet and to avoid duplicate address. The four numbers in an IP address are used in different ways to identify a particular network. The general internet registries such as APNIC, RIP, NCC and LACNIC assigns internet or IP addresses from the following 3 classes.

• Class A- IP address from 0-126. It supports 16 million hosts and 126 networks.
• Class B- IP address from 128-191. It supports 65,000 hosts and 16,000 networks.
• Class C-IP address from 192-223. It supports 254 hosts and 2 million networks.

The number of unassigned IP address is running out and a new classless scheme called CIDR is replacing the classes based system of the IP address. In this system the A, B and C class is tied to adoption of IPV6.

Every device connected to the Internet must need a unique identifier, which is called an IP address. An IP address is a numeric value separated by periods into four octets. These numbers are usually assigned to the ISPs (internet service providers) within region-based blocks. An IP address can be used to identify a region or a country. An internet user’s geographical location can be determined with the help of an IP address. The number system is generally difficult to remember so the IP address may also assign to a Host name.

The host names are usually easy to remember. In simple words, every website on the internet must bound or mapped with an IP address. At one time ISPs usually issue one IP address to each user. Within each ISP a DHCP (Dynamic host configuration protocol) server is configured, which dynamically assigns IP addresses from a given pool to each user who connects to the ISP. Dynamic IP addresses also limit the ability of a user to host websites, mail servers, ftp server, mail server and web portals.

Understanding IP Addresses Scheme

An IP address is an address that is used to uniquely identify a device or computer on an IP-based network. An IP address is an address used to uniquely identify a device on an IP network. An IP address can be divided into two parts network portion and a host portion. Each IP address is associated with a subnet mask. The 32 bit address is broken into 4 octets and 1 octet=8 bits. Each octet is converted to a decimal and is separated by periods.

For example 0000000000.11111111.00000000.11111111 this is a binary representation of an IP address. Each octet’s decimal value ranges between 0 and 255. The binary octets convert into decimal value. Here you can see that how a binary octet converts into decimal value. The right most bit or least significant bit of an octet will hold a value of 20.
The bit left to that bit will hold a value of 21. This process continues until the left most bit or the most significant bit holds the value of 27. If all the binary bits are one the decimal representation will be like this.

1 1 1 1 1 1 1 1
128 64 32 16 8 4 2 1 (128+64+32+16+8+4+2+1=255)

Now here is a sample conversion of the octet if not all the bits are set of 1.

0 0 1 0 0 0 0 1

0 0 32 0 0 0 0 1 (0+64+0+0+0+0+0+1=33)
In the following example you can see the IP address representation both in binary and decimal values.

64. 2. 135. 19 (decimal)64+2+135+19=220
01001010.00000010.1000111.00010011 (binary)

The octets are broken down to provide a large number of the addressing scheme that can accommodate small and very large networks. There are five different classes of the IP networks. Class A, B, C, D and E. The classes from A to C and mainly in use, D and E are experimental and reserved so they are not commonly in use. Due to the classless inter domain routing (CIDR) these addresses are not practically in use.

Network/Subnet Masks

A network mask helps you which portion of the address identifies the network portion and the host portion of an IP address. The three different classes of the IP addresses have their own default masks as shown below.
Class Subnet Mask

Class A: 255.0.0.0
Class B: 255.255.0.0
Class C: 255.255.255.0

An IP address on a class A network that has not been subnetted would have an address and subnet mask pair such as 10.111.20.1 255.0.0.0. If you want to know in more detail that how a mask help you identify the network and host part of the address simply convert the IP address and subnet mask into the binary numbers.

4.16.15.1= 00000100. 00010000.00001111.00000001
255.0.0.0 = 11111111. 00000000.00000000.00000000

If you have the address and the subnet mask in the binary forms then identifying the network portion and the host portion is very easy. Any address value that has the corresponding subnet mask binary value set to 1 show the network ID. Any address bit that has corresponding subnet mask value to 0 represents the host ID.

4.16.15.1= 00000100.00010000.00001111.00000001
255.0.0.0 = 11111111.00000000.00000000.00000000

Network id | host id If you know your IP address of a computer, you can access the services such as online games, FTP, Web and Mail servers, and remote access utilities such as Remotely Anywhere, PCToGo, PCAnywhere, Remote control etc.

How do I change my IP address?
There are a number of methods by which you can change the IP address of your computer.