Network/Port Address Translation

2nd Topic for the week!~

Network Address Translation(NAT)

It is the process of mapping internal private IP address to a pool of global IP addresses (provided by the Internet Service Providers).
It allows one to one, and many to many IP translations.

When a organisation has many users, it is pointless to purchase an equal number of global IP addresses from the Internet Service Providers. So what can be done is to set up a private network using private IP addresses. Now, since private IP addresses can be repeated as many times as possible in private networks, they need something to allow their users to access the Internet normally. That is where the NAT would come in, mapping global IP addresses to private IP addresses allows users from private networks to access the Internet as per normal.

Port Address Translation(PAT)


Port Address Translation is an extension of Network Address Translation that allows multiple devices on a local area network (LAN) to be mapped to a single public IP address. The goal of PAT is to conserve IP addresses.

With PAT, multiple computers can be given the exact same IP address but with different port numbers assigned to it. This can happen simultaneously, and the router would still know which computer to send specific packets to because each computer has a unique internal address.

Port Address Translation is also called porting, port overloading, port-level multiplexed NAT and single address NAT.