What is IP Address? Explain its different classes. 

IP Addressing is an Internet Protocol or IP is an address of a computer or other network device on a network using IP or TCP/IP. IP address is a 32-bit binary number. Some of the bits in the address represent the NETWORK Segment and other bits represent the HOST. This address is separated by dots into four 8-bit octets, and each octet is converted to a single decimal value. Each decimal number can range from 0 to 255, but the first number cannot be 0.

All four numbers cannot be 0 (0.0.0.0) or 255 (255.255.255.255) because

0.0.0.0 Network ID

255.255.255.255 Broadcast ID

IP address is represented by two ways - 1). BINARY              2). DECIMAL

For example, the number "192.2.5.23" is an example of DECIMAL address.

the number "11000000. 00000010. 00000101. 00010111" is an example of BINARY address.

CLASSES OF ADDRESS

There are five classes of 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.

CLASS A

Range: - 1.0.0.0 to 127.255.255.255

Number of Networks: - 126 (IP Address 127.0.0.1 is reserved)

->>These address 127.0.0.1 is a special purpose address reserved for use on each computer. 127.0.0.1 is conventionally a computer's loopback address.

Network software and utilities can use 127.0.0.1 to access a local computer's TCP/IP network resources. Messages sent to loopback IP addresses like 127.0.0.1 do not reach outside to the local area network (LAN) but instead are automatically re-routed by the computer's own network adapter back to the receiving end of the TCP/IP stack.

Typically all IP addresses in the range 127.0.0.1 - 127.255.255.255 are reserved for private use.

No. of Nodes Per Networks: - 16 million (16,777,214)

Default Subnet mask: - 255.0.0.0

Use: - This type of allocation is generally given to very large networks such as multi-national companies.

CLASS B

Range: - 128.0.0.0 to 191.255.255.255

No. of Networks: - 16,382

No. of Nodes Per Networks: - 65,534

Default Subnet mask: - 255.255.0.0

Use: - These blocks are generally allocated to Internet Service Providers and large networks, like a college or major hospital.

CLASS C

Range: - 192.0.0.0 to 223.255.255.255

No. of Networks: - 2,097,150

No. of Nodes Per Networks: - 254

Default Subnet mask: - 255.255.255.0

Use: - This type of class is generally given to small to mid-sized companies.

CLASS D

Range: - 224.0.0.0 to 239.255.255.255

Use: - These addresses in this class are reserved for a service called Multicast.

CLASS E

Range: - 240.0.0.0 to 255.255.255.255

USE: - These addresses in this class are reserved for experimental use.

PRIVATE IP ADDRESS

An IP address is considered private if the IP number falls within one of the address ranges reserved for private uses by Internet standards groups. These private address ranges exist:

    10.0.0.0 through 10.255.255.255

    169.254.0.0 through 169.254.255.255 (APIPA only)

    172.16.0.0 through 172.31.255.255

    192.168.0.0 through 192.168.255.255

Private IP addresses  are typically used on local networks including home, school and business LANs including airports and hotels.

Devices with private addresses cannot connect directly to the Internet. Computers outside the local network cannot connect directly to a device with a private IP.