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Time: October 24th, 2023

This post includes an ultimate review of NAT (Network Address Translation). Keep scanning to learn more about NAT, including its definition, purposes, working principles, and different types of NAT. By reading this article, you can have a better understanding of NAT.

What is NAT (Network Address Translation)

We can utilize a private IP address on our private network instead of the one public IP address required to access the Internet. A technique known as NAT (Network Address Translation) converts one or more local IP addresses into one or more global IP addresses and vice versa in order to give local hosts access to the Internet. In the packet that will be routed to the destination, it also translates port numbers, masking the host's port number with a different port number. The NAT table is then updated with the relevant IP address and port number entries. NAT often uses a router or firewall to function. A networking system needs a unique IP address to communicate with the internet. This 32-bit number identifies and locates the network device so that users can communicate with it.

How Does NAT Work

How does NAT take effect? A NAT firewall can function as an intermediary between the public network and private networks—the internet and any local networks—through network address translation. This enables every member of a group of devices to act outside of their network using a single distinctive IP address.

The border router, which typically has one interface in the local (inside) network and one interface in the global (outside) network, is set up for NAT (Network Address Translation). NAT changes a local (private) IP address into a global (public) IP address when a packet travels outside the local (inside) network. When a packet enters the local network, its global (public) IP address is converted to a local (private) IP address.

The packets will be lost and an Internet Control Message Protocol (ICMP) host unreachable packet will be sent to the destination if NAT runs out of addresses, that is, if there are no more addresses in the pool configured.

Types of NAT (Network Address Translation)

NAT comes in numerous variations. Moreover, different types of NAT might have a variety of uses. These are common types of NAT (Network Address Translation).

1. Static network address translation SNAT. SNAT uses 1:1 network address translation to translate unregistered IP addresses to registered IP addresses. When a device needs to be accessible from outside the network, it is especially helpful.

2. Dynamic network address translation DNAT. A target is chosen from a list of registered IP addresses by this type of NAT, which then translates an unregistered IP address to the registered one.

3. Reverse network address translation RNAT. RNAT enables people to connect to themselves over a public or internet-based network.

4. Overloading network address translation NAT. NAT overload, port-level multiplexed NAT, single address NAT, and port address translation (PAT) are further names for this. To map several private, local, unregistered IP addresses to a single registered IP address and determine which traffic originates from which NAT IP address, this type of dynamic NAT uses various ports. PAT is typically more affordable than network address translation when several users are connected to the internet using a single public IP address.

5. Overlapping network address translation NAT. When two organizations combine whose networks employ RFC 1918 IP addresses, or when registered IP addresses are assigned to numerous devices or otherwise in use on more than one internal network, overlapping NAT may occur. The networks in both situations must interact, and the organization(s) use overlapping NAT to do so without readdressing every device.

The NAT router intercepts addresses and stores them in a table so that addresses can be replaced with registered unique IP addresses. Both internal IP addresses and registered unique addresses must be translated by the network address translation router into private network-specific IP addresses. To do this, either static NAT or dynamic NAT using DNS may be applied.


That is the ultimate guide to NAT (Network Address Translation).Here, we explained what NAT is, its working principle and the different types of NAT. NAT serves as a firewall to separate the public and private networks. By limiting direct access from the external network, it conceals the internal IP addresses and offers an extra degree of security for the devices behind the NAT gateway. In addition, NAT also possess other beneficial features that worth of your exploration.

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