The main 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 is assigned a private IP address. Now the IP address is the address that helps routers send data to specific machines. Everything connected to the Internet has an IP address, otherwise it cannot be used.
IP, or Internet Protocol, is of two types:
Almost all 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 infancy and IP addresses were created and assigned to computers and other devices, it was believed that there were a large number of addresses for everything connected to the Internet. The total number of IPv4 addresses can be a maximum of 2ˆ32. The way the Internet is used today, 2ˆ32 will not be able to create IPv4 addresses for all the devices people want to connect to the Internet.
That’s why the engineers had to come up with IPv6, which can hold up to 2ˆ128 IP addresses. That’s a huge number, and the researchers believe the new format will be enough to cover all internet-connected objects. However, this will take a long time as old devices need to be retired and new ones need to be deployed to manage IPv6 addresses. In the meantime, NAT is there to help us with IPv4 addresses.
What does NAT do?
NAT, or Network Address Translator, is placed on the device that sits between the network of your computers/IoT devices and the Internet. This device is usually a router because most of us use the router to create a firewall. It can also be a modem, a connected telephone or a computer acting as a server. Either way, it’s there to give a public IP address (IPv4) to your entire computer and IoT (Internet of Things) network.
That is, instead of assigning IPv4 addresses to each device on your network, NAT gives a single IP address. All other devices on your computer/IoT are given a private (internal) IPv4 address. It can be anything between 192.168.0.0 and 192.168.255.255. Data packets from the Internet contain the external IPv4 address in their header. Depending on the type of data, the NAT (Network Address Translator) forwards it to private or internal devices so that the data can be processed as needed.
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In short, NAT helps control IPv4 address exhaustion, managing the local or private (or internal) IPv4 addresses of all 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 a total of eight (private) IP addresses. NAT treats them individually within the network, but for the Internet it is a single IP address (single device).
If needed, if you have an IPv6 address, you don’t need NAT. If you’re still on IPv4, you need the Network Address Translator until your network completely switches to IPv6.
Read more: How to change NAT type on Windows PC
The above explains what NAT is and how to use it. You have more questions ? Ask in the comments box below.