NAT stands for Network Address Translator. As evident from its name, it is a translator of network addresses. This post tells you about the need for NAT, what it does, and why.
What is NAT or Network Address Translator
Network Address Translator, or simply called NAT, is an important part of the device between your LAN and the Internet. It could be located in the router you are using to connect the local network to the Internet or any similar device, like a modem. Using a router for NAT is especially better because you can also set up your firewall using the router.
The primary function of NAT is to manage IP addresses so that outsiders cannot hack into your network. A home or office network contains many devices such as computers, tablets, printers, scanners, and phones to name a few. Each one is assigned a private IP address. Now, the IP address is the address that helps routers in sending data to specific machines. Anything connected to the Internet has an IP address else it can’t be used.
IP, or Internet Protocol, is of two types:
Almost all the computers and other devices connected to the Internet have an IPv4 address. The ‘v’ in ‘IPv4’ stands for ‘version’. When the Internet was in its formative years and IP addresses were being created and assigned to computers and other devices it was thought that there is an ample number of addresses for everything connected to the Internet. The number of total IPv4 addresses could be a maximum 2ˆ32. The way the Internet is used now, 2ˆ32 will not be able to create IPv4 addresses for all the devices people want to connect to the Internet.
That is the reason why engineers had to come up with IPv6, which can hold up to 2ˆ128 IP addresses. That is a huge number and researchers believe that the new format will be enough to cover all the objects connected to the Internet. This, however, will take a long time as older devices have to retire, and the new ones have to be deployed that can handle IPv6 addresses. In the meantime, NAT is here to support us with IPv4 addresses.
What does NAT do?
NAT, or the Network Address Translator, is placed on the device that sits between your computers/IoT devices network and the Internet. That device is usually router as most of us use the router to create a firewall. It can also be a modem, a tethered phone, or a computer acting as a server. Whatever it may be, it is present there to give a public IP address (IPv4) to your entire computer and IoT (Internet of Things) network.
That is to say that instead of assigning IPv4 addresses to each device on your network, NAT gives out one single IP address. All other devices in your computer/IoT are given one private (internal) IPv4 address. It can be anything between 192.168.0.0 and 192.168.255.255. The data packets coming from the Internet, contain the external IPv4 address in their header. Based on the type of data, the NAT (Network Address Translator) forwards it to the private or internal devices so that the data can be processed as required.
In short, NAT helps control the IPv4 addresses from running out, by managing local or private (or internal) IPv4 addresses of all the entities on a computer and/or IoT network. So, if there are six computers and two printers on your network, each has a private IP address, making it a total of eight IP addresses (private). NAT treats them individually within the network but for the Internet, it is just one (single device) IP address.
Coming to need, if you have an IPv6 address, you do not need NAT. If you are still on IPv4, you need the Network Address Translator until your network completely moves to IPv6 format.
The above explains what is NAT and its use. Have more questions? Ask in the comments box below.