What is NAT?

 

NAT stands for Network Address Translation and it is used to convert a private IP address into a public and a public IP address into a private, but the question is why do we need to convert the private IP address into the public or a public IP address into private I am going to explain you everything including this I will also explain to you what are the advantages and disadvantages of NAT in a computer network.

 

 

IP version 4

 

İp version 4 is a 32-bit address and it has around 4.2 billion of IP addresses, but the population of our beautiful world is around 7.2 billion, according to 2018 and most of the users are also using multiple devices such as a smartphone laptop desktop tablet etc.and for accessing the Internet all this device need I P address right. So, 4.2 billion of IP address is not sufficient for more than 7.2 billion of users, so, for this reason, we are using NAT. NAT is used to convert a private IP address into the public and a public IP address in the private so how this entire concept of NAT that is Network Address Translation works let’s find out.

Let’s take an example, there are four computers in a network, but only one Internet connection. Now the question is how it is possible for these four computers to access this single internet connection at the same time it is possible with the help of NAT that is Network Address Translation

 

 

Here all the four computers are assigned to the private IP address such as 10.0.0.1, 10.0.0.2, 10.0.0.3 & 10.0.0.4 and this private IP address are not writable on the internet It means the same address can be used an unlimited number of times on the different network. I have created a separate post on what is private and public IP address if you want to know more about this follow the link given in the description section below now let’s concentrate on NAT whenever the PC 1 assign with the private IP address 10.0.0.1 wants to access the internet it will first send a request to the router, your router is going to convert this private IP address into public and add a unique port number to it and save this information in its NAT Forwarding Table after that it will forward the request to the internet. So like this with the help of port number it will be easy for the Router to remember which device has requested in the packet now the time your router receives the reply from the internet it is going to check it NAT Forwarding Table and convert this public and P across into private and send the packet to the requested at PC. This is how the entire concept of NAT works. Let’s take another example so that it will be easy for you to understand. The time PC 2 assigned to the private IP address 10.0.0.2 wants to want to access the internet it will first send a request to the router your router is going to convert this private IP address into public and add a unique port number to it and save this information to its NAT Forwarding Table. After that it will forward the request to the internet so like this it will be easy for your router to remember which device has requested in the packet now the time your router receives a reply from the internet it is going to check it NAT forwarding table and convert this public IP address into private and send the packet to the request at PC so this is the basic concept of NAT that is Network Address Translation. Do you know one interesting fact about NAT?

For Internet your entire device in the private network is look-alikes one single device this is because public network only knows this single public IP address of your network not the private IP address of devices in a network like this NAT helps you to hide the real IP address of your network from the external user and act as a firewall. So, guys, this is the basic concept of NAT. Now, let’s find out what are the advantages and disadvantages of using NAT in a computer network.

 

I hope it has been a useful article.