Network Address Translation allows private IPv4 addresses to be translated to an IPv4 public address to communicate over the Internet. This saves public IP addresses as not every device needs a public IP address and if we allowed that we would’ve run out of IPv4 addresses by now.
NAT allows multiple private IPv4 addresses to be translated to one public IP address, therefore saving public IP addresses.
There are three different types of NAT.
- Static NAT – This is a one-to-one translation, one private IP address will be translated to one public IP address
- Dynamic NAT – You don’t need to manually map each IP static with dynamic NAT but you do need to ensure you have enough public IPs for the private IPs to be translated to.
- Overloading (PAT) – This is a many-to-one translation, multiple private IP addresses will be translated to one public IP, kinda cool right? This is the reason we haven’t run out of IPv4 addresses yet.