All IPv4 address can be divided into two categories:
- Public and
Public IP address:
- These address are meant for the external world that is for the internet.
- These are also known as WAN address.
- These address are routed on the internet.
Private IP address:
- These address are not seen on the internet that is they are reserved for internal use behind a router or or other NAT devices.
- They are also referred as local IP address.
- They are used within a particular organization or a network(LAN) and cannot be used to communicate with the internet that is with external world.
- This is one of the solution to overcome with the depletion of IPv4 addresses.
Classful IP address:
In classful address, there are five classes that is
Class A : 0.0.0.0 to 127.255.255.255
Class B : 128 .0.0.0 to 184.108.40.206
Class C : 192.0.0.0 to 220.127.116.11
Class D: : 18.104.22.168 to 22.214.171.124
Class E : : 126.96.36.199 to 255.255.255.255
For each class, there is a Private IP address:
Class A : 0.0.0.0 to 127.255.255.255 PA : 10.0.0.0 to 10.255.255.255
Class B : 128 .0.0.0 to 188.8.131.52 PA : 172.16.0.0 to 172.31.255.255
Class C : 192.0.0.0 to 184.108.40.206 PA : 192.168.0.0 to 192.168.255.255
Example of Private IP address:
- Consider a organisation system with Private IP address and a NAT router which translate these private IP address to companies single public IP address used for connecting to external world.
- Again for response these this public IP address are translated to specific private IP address
- On the NAT router there is a mapping for internal Private IP address along with the Port used for application(PAT)
Leave a Reply