Network Layer:-

Internet Protocol(IP):-

• It is a network layer protocol for source to destination, host to host and end to end delivery of packets (OSI model) or data-gram (TCP IP model) on the basis of IP address. Hence, it only provides transmission services and addressing services.
• It is connection-less hence not reliable and there is no error control and flow control but it is fast.
• It defines IP address IPV4 & IPV6.

IPV4(Internet Protocol Version 4):- Part 1

• The address size is 32 bits hence the address space is 2^32 that is around 4 Billion.
• The address defined in binary notation and doted decimal form ranging from 0.0.0.0 to 255.255.255.255.
• There is an unnecessary wastage of addresses by adapting class full addressing.

Class full addressing:-

• Class full addressing is wastage of IP addresses because in this the IP addresses reserved for certain purpose and can not shared with uni-cast addresses.
• For Example:- Network address is the address in which all the host bits are zero.
• Example:- 10.0.0.0 is a Class A network address.
• 130.1.0.0 is a Class B network address.
• If all the host bits are 1 then it is a Broadcast address.
• Example:- 11.255.255.255 is a Class A broadcast address.
• 222.1.2.255 is a Class C broadcast address.
• In Class A 0.0.0.0 is reversal for backbone network address and 0.0.0.1 to 0.255.255.255 is reversal for backbone hosts.
• 127.0.0.1 to 127.255.255.254 is reserved for loop back addresses which used for detecting the faults and errors in the network.

NOTE:- Backbone address and loop back addresses defined only in class A where as network address broadcast address and private addresses defined in class A, B, C and not in D & E.