What is a NAT Firewall?


What is a NAT Firewall? The victimization of the ordinary netizens by unauthorized users called hackers have been increased exponentially. These hackers break into your computer and misuse your information for spamming (read 7 ways to avoid being hacked). There are a lot of tools in the market that has been introduced to reduce the threat of cybersecurity. One of these tools is the NAT Firewall. The NAT Firewall is used to add an extra layer of security to your internet network.

What is a Firewall?

In computer networking, the term firewall refers to a system of network security. That monitors and controls the data flow. That is going out and coming in. Based on the predefined security criteria. Internet data is in the form of packets of information. That is sniffed thoroughly by the firewall. To make sure there is no malicious stuff coming from the external source. The firewall can be hardware or software and even the combination of both. It works as a barrier between a trusted internal network. And an external network and provides a secure connection.

What is a NAT Firewall?

The term NAT stands for Network Address Translation. It is used to translate the IP addresses. Of a lot of devices connected to a local area network to a single IP address. This IP address is usually employed by the routerThat is being used to connect the device to the internet. This makes the other external devices that intend to access the computers in the local network. See the single IP address of the router. Hiding all the devices IP addresses from the external threats. However, the router can be configured as a firewall. That will shield the network and will allow only the authorized device.  access the computers on the local network. This can add an extra level of security to your internet network that will block any unauthorized attempt of accessing your internet network.

How a NAT Firewall Works?

After allowing the authorized system to access any device in the local area network, the NAT then translates the IP address of the router to a particular computer address. This address is predefined in the NAT table that defines the internal IP addresses of all the devices connected to the local network. This table also describes the world wide web address viewed by the devices outside the network. Although every device connected to the local network has its IP address, the external sources can only see the IP address of the router when connecting to any of the devices in the local network. In short, The NAT firewall works as a middleman between a group of computers connected to a local network and the internet or the world wide web.


The NAT firewall blocks all the unauthorized systems trying to access the local area network by the rules predefined in the NAT table. To understand it easily look at this example. By giving an example of three devices named 1, 2, and 3. Let’s connect all the three devices to one local network. If device 1 wants to call device 4 which is outside the network, the call will first go through a gateway.

This gateway will then intercept the call, replacing the IP address of device 1 with the IP address of the gateway and makes the call on its behalf. Thus, device 4 would think that the call is from the gateway. And it will keep the identity of the actual caller (device 1) in secrecy. And it does not matter for device 4. Now, device 4 replies to the call to the gateway. And the gateway forwards the response to the device 1. It will be unaware of the switches it has on the way.

A Gateway

The gateway is the NAT firewall that works as an agent between an internal device 1 in the local network and the device 4 outside the network or the internet. When you attempt to access any website you need to have an internet connection network. The NAT Firewall of this network translates the IP address of your device to its own and sends your request to the server of the website (that can see the IP address of the router only). 

Importance of NAT Firewall

As previously discussed that the NAT firewall adds an extra level of security to the Internet network (read more about internet security and privacy in our ultimate privacy guide). It scans all the access requests coming to any device from outside the network. If these requests are legitimate, then the NAT firewall allows the system to access the device inside the network. 

VPNs With NAT Firewall

Using VPN with NAT Firewall will more likely diminish the effect of the NAT Firewall. It is because the NAT firewall scans the data packets and then allows it to access any device on the network. But these packets become unreadable when using a VPN because it encrypts all the data traffic (know more about best encrypted VPN). However, there are some VPNs available in the market which are compatible with NAT Firewall and do not make the NAT firewall ineffective.

Conclusion – What is a NAT Firewall?

In a nutshell, the NAT firewall provides a subsidiary level of security to a local internet network connection. It shields the computers from all the malicious stuff send by the external sources. Thus, if you want to feel safer over the internet, you are highly recommended to use NAT firewall and save your device from the external threats of hacking and identity theft (get the most secure VPN services for high-end internet security and privacy).

The cybersecurity challenge has fueled up the development of these network security systems. People around the world are now looking for the necessary security measures to feel safe over the internet and preserve their online privacy. Thus, the NAT firewall is an essential tool to add an extra level of security to your computer network.


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