Network Address Translation Explained With Simple Example
by Network Address Translation or NAT is a method to map multiple local private IP address to one or more public IP addresses. To achieve this generally a network device for eg: Router which is sitting in the private network, changes the source IP and port field of the IP header in a packet.
Since IP Addresses are limited (IPv4) and as internet devices are too large in number. Hence, NAT is used to apply one or more public IP addresses to a pool of devices present in a private network to save IP addresses.
Theoretically using NAT one public IP Address is sufficient for an ISP hosting a large number of subscribers.