What is nat in a router?

Many users, having a router, think that they only need it so that only they can connect to the Internet. In fact, it also performs the function of connecting other users to the server. In this article we will tell you what NAT is in a router, why it is needed and how to configure it.

NAT in a router - what is it?

Network Address Translation is translated from English as “network address translation” - this is the process of translating internal addresses into external addresses. If this function is not configured, the router will block access to any ports to all incoming connections from the global Internet, but if the parameters are configured, it will allow.

Settings

To configure nat in the router yourself, you need to perform the following series of steps:

• Launch any browser on your computer and type the address of this device 192.168.1.1 or 192.168.0.1 in the search bar.
• Then enter the username and password Admin/Admin. Afterwards, you can replace this login and password with your own.
• In the window that opens, select Settings - Network - Routing (routes) and click on New rule, which will allow you to set routing conditions in any way. There are five ways: through DNS name, port, broadcast to a specific user, network interface, or address substitution using the source address.
• Next, you need to set traffic conditions using one of the four proposed options (Auto, Gateway, Trunk, Interface) and click “Next” and “Close”.

After completing this series of steps, the router is ready for use.

There are times when you need to configure nat on your computer. To do this, go to “Control Panel” through “Start” and launch “Network Connections”. Select a new network device and right-click on it, in “Properties” select “Advanced”. And check the box next to “Allow other network users to use this connection” and click OK.

Setting up loopback

The meaning of the nat loopback is that if a packet comes from the internal network to the external IP address of the router, it is considered to have come from outside - which means that the firewall rules relating to external connections apply. If the packet successfully passes through the firewall, then nat is triggered, which becomes an intermediary between two computers located on the same network.

Attention! Without the nat loopback function, it would be impossible to find out about the network service settings or access the server. For each domain it would be necessary to configure the hosts file manually.

Nat types

There are several types of Network Address Translation. Let's look at each of them in detail:

• Static NAT is used only by companies, since they have many IP addresses that do not change and must always be accessible from the outside. For example, in order to open a website, you need to know its IP address and port, but since the port is always automatically entered by a special program, you only need to know the DNS name. User addresses on the Internet are not visible.
• Dynamic NAT. When the user is on the Internet, the router itself selects only one among the received IP addresses, and then enters it into the nat table.This record is immediately erased as soon as the user leaves the network.
• PAT or NAT Overload. This type is more suitable for users as individuals. Since a single external address and two ports (internal and external) are issued, which are specified by the users themselves. You can access this service only using a specific program.

Important! Often ports need to be configured manually.

How to change the type

In order to change the NAT type from one to another, you need to go to your router by entering the combination 192.168.1.1 or 192.168.0.1 in the search line of your browser, and enter your username and password. Then look at your IP address and network settings of your device. Then you need to contact your Internet connection provider so that they can reconfigure your router to the type you need. To do this, he will need to provide all the data.