Internet Protocol

IP is used by the Internet (The world's largest Internetwork, which Connect thousands of networks worldwide) and within many companies. its addresing scheme scales well for global addressing although, like the telephone industry, address space is running out.
IP use centrally administered major network numbers to allow internetworks to connect to the internet. if you require internet connectivity, you will need to get network address space from an organization called the InterNIC. (The InterNIC controls address allocation for the Internet).

Network Numbering
The IP address space is 32 bits long and is used to represent both the network and the node, an IP address is writtenas four decimal numbers separated by dots (Called dotted decimal notation); for Example, 172.16.10.1. each of the four numbers is called an octet because it represents 8 bits, and each octet has a maximum value of 255. for routing purpose, the IP address is broken into three parts: Major network, subnet, and node. see picture :



172.16.0.0 network is the class B, the subnet mask is 255.255.255.0 networks are uniquely numbered at the third octet, subnets 1,2,10,20,30 and 40 have been assignet to the distinct networks. please see picture :