IP ADDRESSING(http://mynetworkplanet.blogspot.com/2009/07/ip-address.html)
sabyasachi
A unique number called the internet protocol (IP) address identifies
every machine that is on a network. The IP address is a unique 32 bit
logical address expressed as four decimal numbers, each representing
eight bit, separated by periods, for example 192.168.1.1 . IP
addresses are two types, static and dynamic. Static IP addresses never
change. Example a device assigned a static IP address will always use
the same address. On the other hand, in dynamic IP addressing the IP
address for a device will change each time the device connects to the
network.
Class full IP Addressing:
The scheme of IP addressing using address classes is called class full
IP addressing. This addressing scheme does not allow any other network
prefix address. IP address contains two addresses embedded within one
IP address: network address and host address. The class of the address
determines which part belongs to the network address and which part
belongs to host address. They are divided into various classes namely
class A, B, C, D, and E. Class D is used for multicasting while class
E is used for Research and Development propose.
* Class A IP Address: Class A IP address consists of an 8 bit
network id and 24 bit host id. This class divided into 128 network
blocks (numbers of networks) where the first network block address
starts from 0.0.0.0 to 0.255.255.255, where the first byte identifies
the network. The first network block and the last network block are
reserved. Hence, class A provides 128 network blocks while each block
in class A provides 16,777,214 host addresses. An example of a class A
IP address is 102.32.16.105, where “102” identifies the network and
“32.16.105” identifies the host on that network.
o 8-bit network ID and 24-bit host ID.
o (2^24)-2= 16,777,214 host address.
o 128 networks block.
o Network block 0.0.0.0 to 0.255.255.255 and 127.0.0.0 to
127.255.255.255 are reserved for special propose.
o Network block 10.0.0.0 to 10.255.255.255 is used for
private network.
o 125 network blocks are used for public network.
* Class B IP Address: Class B addresses consists of a 16-bit
network id and 16-bit host id. This address class consists of 16,384
network blocks. The first block starts from 128.0.0.0 to
128.0.255.255. in this address class the first two bytes represent
network id that is 128.0.X.X where ‘X’ is any number between 0 to 255.
Class B provides 16 special and reserved network address blocks. Each
network address block in this class contains 65,536 host address. An
example of a class B IP address is 168.212.226.204 where “168.212”
identifies the network and “226.204” identifies the host on that
network.
o 16 –bit network is and 16-bit host id.
o (2^16)-2 = 65,534 host address.
o 16,384 network block.
o 16 special and reserved network address blocks.
o 16,368 network blocks are used for public use.
* Class C IP Address: A Class C IP address consists of 24-bit
network id and 8-bit host id. The first network blocks started from
192.0.0.0 to 192.0.0.255. The address class supports 2,097,152 network
blocks. In this address class, the first three bytes represent the
network is that is 192.0.0.X where ‘X’ is any number of 0 to 255.
Class C provides 256 network blocks, which are reserved for private
addresses. Each block of class C address provides 256 host addresses.
An example of a class C IP address is 200.168.221.226 where
“200.168.221” identifies the network and “226” identifies the host on
that network.
o 24-bit network id and 8-bit host id.
o (2^8)-2 = 254 host addresses.
o 20, 97,896 network blocks are used for public use.
o 256 network block which are used for private address.