What is NAT PAT in Networking? – PAT (Port Address Translation) works very differently from Static and Dynamic NAT. PAT adds port numbers to the source part of the private IP addresses and maps them to the global IP address. The most widely used type of NAT is PAT.
What is NAT PAT in Networking?
What is NAT PAT in Networking?
In network environments, the private IP addresses use on the local network. Local private IP addresses can not access the Internet directly. In order for computers on the local network to access the Internet, a Public (Global) IP address assigned by the ISP (Internet Service Provider) is needed.
When you buy an ADSL line to your home or office, an ISP usually gives you an ADSL Modem. Once you have set up the Internet, your computers on the local network can access the Internet.
While access the Private IP addresses to the Internet, it converts by NAT configured as active on the ADSL Modems. A computer with a private IP address can only access the Internet through NAT.
In this article, we will talk about PAT (Port Address Translation), another type of NAT.
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Understanding NAT and PAT
PAT is a different kind of NAT. The computers on the local network use NAT when leaving the Internet. Above we talked about Internet connection of home users. If one network environment owned by a home user or a small business, they own one ISP Public IP address.
Also referred to as PAT (NAT Overload).
By configuring individual computers in this network environment, we can take them to the Internet with Static NAT. If Dynamic NAT applied to this network environment, only one computer can access the Internet with a single IP address, but the second computer will wait for the session to be shut down.
The most commonly used method is the NAT PAT method. In this network environment, PAT can be applied.
The general working logic of NAT is as shown in the following figure.
Computers on the internal network are subject to NAT processing while providing access to any website on the Internet.
How Does PAT Work?
The above operation is only general working logic. To answer questions about how does PAT works, let’s examine the network topology created in the Cisco Packet Tracer program.
The entries in the above display are NAT records originated on Cisco Router0 when pinging PC0 and PC1 to the Router1 at the same time. 192.168.10.10 and 192.168.10.20 Ip addresses converted to 10.0.0.1 Ip addresses. If we defined a single IP address by creating a single access list in Dynamic NAT, then one of the two computers would fail to ping.
The biggest advantage of the PAT process is that it can take more than one computer to the Internet at the same time. This process is done by port numbers to match IP addresses. Thus, all the computers on the network will be able to access the Internet with a single Public IP address.
NAT uses PAT numbers to match IP addresses. In addition, the NAT PAT configuration on Cisco Routers is configured with the command in the image above. In addition, it can be created in Static PAT for a specific computer on the Cisco Router.
For basic use of Cisco Packet Tracer, you can read the article called “How to Use Cisco Packet Tracer Step by Step?“.
Understanding NAT PAT in Networking ⇒ Video
To understand NAT PAT in networking, you can watch the video below. Also, you can subscribe to our YouTube channel…
What is NAT PAT in Networking? – PAT is widely used and is the most recommended method. The configuration you watch on the video best explains the PAT’s working logic.