is a 32 bit binary number which is divided into four part of 8bits each(octance)
8bit 8bit 8bit 8bit
10 . 0 . 5 . 1 –>IP address(network id + Host id)
255.255.255.0 –> Mask
Networkid and host id are based on network mask. In the above example 10.0.5 is network id & 1 is hostid.
CLASSES OF IP ADDRESSES:
CLASS A: if the first number in ip address is b/w 1-127. the subnet is 255.0.0.0. it supports 16 million computers.
CLASS B: if the first number in ip address is b/w 128-191. the subnet is 255.255.0.0. it supports (65534-2)65532 computers.
CLASS C: if the first number in ip address is b/w 192-223. the subnet is 255.255.255.0. it supports (256-2)254 computers.
most of the ip address are public, they are managed by ICANN. Some ip addressed are private, private are free, for example in Class A(192.168.0.0), Class B(172.16.0.0-18.104.22.168), Class C(10.0.0.0)
the first and last ip in any range can not be used, as first is reserved for host and last for broadcast.