What is IP address? Classes of IP?

What is IP address?   Classes of IP?

                                               Posted by   :  mayur kakade...... :-)

What is IP address 

Every machine on a network has a unique identifier. Just as you would address a letter to send in the mail, computers use the unique identifier to send data to specific computers on a network. Most networks today, including all computers on the Internet, use the TCP/IP protocol as the standard for how to communicate on the network. In the TCP/IP protocol, the unique identifier for a computer is called its IP address.

Address serves two principal functions: host or network interface identification and location addressing

For example, the number "69.72.169.241" is an example of such an address. These addresses are similar to an addresses used on a house and is what allows data to reach the appropriate destination on a network and the Internet.

There are five classes of available IP ranges: Class A, Class B, Class C, Class D and Class E, while only A, B, and C are commonly used. Each class allows for a range of valid IP addresses. Below is a listing of these addresses.

Classes	Information
Class A	Uses first 8 bits for Network ID & Last 24 bits for Host ID.
Class B	Uses the first 16 Bits for Network ID & the last 16 bits for Host ID
Class C	Uses the first 24 Bits for Network ID & the last 8 bits for Host ID
Class D	Represents a 32 bit multicast group ID
Class E	Currently not being used

This is the classification of IP address

Class	Address Range	Supports
Class A	1.0.0.1 to 126.255.255.254	Supports 16 million hosts on each of 127 networks
Class B	128.1.0.1 to 191.255.255.254	Supports 65,000 hosts on each of 16,000 networks.
Class C	192.0.1.1 to 223.255.254.254	Supports 254 hosts on each of 2 million networks.
Class D	224.0.0.0 to 239.255.255.255	Reserved for multicast groups.
Class E	240.0.0.0 to 254.255.255.254	Reserved for future use, or Research and Development Purposes.

Ranges 127.x.x.x are reserved for the loopback or localhost, for example, 127.0.0.1 is the common loopback address. Range 255.255.255.255 broadcasts to all hosts on the local network.

Automatically assigned addresses

There are several IP addresses that are automatically assigned when you setup a home network. These default addresses are what allow your computer and other network devices to communicate and broadcast information over your network. Below is the most commonly assigned network addresses in a home network

IP	Assigned
192.168.1.0	0 is the automatically assigned network address.
192.168.1.1	1 is the commonly used address used as the gateway.
192.168.1.2	2 is also a commonly used address used for a gateway.
192.168.1.3 - 254	Addresses beyond 3 are assigned to computers and devices on the network.
192.168.1.255	255 is automatically assigned on most networks as the broadcast address.

If you have ever connected to your home network, you should be familiar with the gateway address or 192.168.1.1, which is the address you use to connect to your home network router and change its settings.