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IP Addressing


I try to discuss in brief some key terms in IP Addressing in networking.
1.       Class full IP Addressing
2.       Class less IP addressing
In network computer needs to identify their destination and host computer  among others, to communicate each other. So it used 32 bit binary number for that, and split it into equal 4 parts and convert it to decimal for easy use.
E.g   11000000.10100000.00000001.00000001
         192.168.1.1
 To identify one computer from large network is not easy by concerning one by one digit. So that there are two things within on IP. Network address and Host(computer or any device) address.

This process like this, when we post a letter it address look like this,(No 35,Reid Avenue,Colombo 07).If we post that letter from galle the post office(galle) just looks the colombo and sends it to the colombo.Rest of the parts of address (road and number) looks by colombo post office.The IP address also looks like that.Router look the network address and try to send it to that network.In that network it looks which host that it should go.


So that we split this IP into main two parts.(splitting parts are only logicaly not in physically.)
for e.g. if we take 192.168.1.1 class C address the network address is 192.168.1.0.

Network address is taken from all the host site bits concern as Zero.In above eg 192.168.1 part belongs to network and other 8 bits belongs to hosts site.When all hosts site bits takes as zero network address is given.When we give all hosts site bits as 1 (ones) that give broadcast address. 192.168.1.255 is the broadcast address.




According to dividing position there were 4 main classes.
Class A =  8 bits for network 24 for host.  Within this class there are nearly 2 to power 8 difference network addresses and 2 to power 24 difference hosts can keep in each network. Likewise in class B there are 16 bits for network and hosts class C 24 bits for network and 8 bits for hosts.
But in this system IP addresses are limited to nearly 4 billon and it is now not enough. Even if we need to 10 computer lab to give IP’s we had to take class C IP address. And  in class C there are 256 hosts can give IP’s in one network. Thing getting worst when we concern Class A and B.
So this is now not in use. Subnet mask address is replaced that. In subnetting the pointer of network and host dividing can keep any bit position within 32 bit number. That help to reduce wastage of IP address.
Next article will discuss about classless IP. (Subnetting)
Location: Sri Lanka

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