IPv4  Reserved Addresses

There are some IPV4 address that can be used in the internet. These are special address and meant for the special purpose.

Private IP Addresses

The IP address have three classes that address which you use must belong to one of these classes.

The address which we used outside is public address and the address which we use inside the network is private address.

Private address is mainly used for testing and message exchange within local network.

In order to communicate with the outside world, these IP addresses must have to be translated to some public IP addresses using NAT process, or Web Proxy server can be used.

Loopback IP Addresses

The IP address range 127.0.0.0 – 127.255.255.255 is reserved for loopback, i.e. a Host’s self-address, also known as localhost address.

The loopback address is mainly used for the testing purpose that is why it is reserved and cannot be used.

Link-local Addresses

In case a host is not able to acquire an IP address from the DHCP server and it has not been assigned any IP address manually, the host can assign itself an IP address from a range of reserved Link-local addresses. Link local address ranges from 169.254.0.0 -- 169.254.255.255.