Public and Private IP address

Public IP is a unique IP so we can access it through the Internet. As we seen before, telephones in our home has its unique address so that we can make call from anywhere in the world.

Public IP Address Range

Class A: 1.0.0.0 to 126.0.0.0 /8

Class B: 128.0.0.0 to 191.255.0.0 /16        

Class C: 192.0.0.0 to 223.255.255.0 /24
Class D: 224.0.0.0 to 239.255.255.255 - Reserved for Multicating. 

/* - no of Network bits.

Private IP address is reserved for LAN purpose. In offices we use extension numbers to make calls between departments (eg: 101, 102, 103) instead of unique telephone number.  Using this extension numbers we can only make calls inside the office not from outside. Private IP is used to connect local computers. We can’t access the private IP computers from outside of its network.

Private IP Address Range

Class A: 10.0.0.0 to 10.255.255.255

Class B: 172.16.0.0 to 172.31.255.255

Class C: 192.168.0.0 to 192.168.0.0