NAT vs. port forwarding

Question

Possible Duplicate: What is port forwarding and what is it used for?

What is the difference between NAT and port forwarding? Are they two different names for the same thing? What would be a short practical example?

Solution

NAT and port forwarding are different, but they are often used in conjunction with each other.

NAT is network address translation. It translates traffic from one IP address to another. An example: NATing your WAN IP address 1.2.3.4 to your internal webserver 192.168.0.1.

Port forwarding (sometimes called PAT - Port Address Translation) is similar, but it functions on the port level. You can forward port 80 from your WAN IP address to your internal webserver, for example. You can also forward to a different port - i.e. port 8080 on the WAN is forwarded to port 80 on your internal web server.

Comments

[Ƭᴇcʜιᴇ007]

possible duplicate of What is port forwarding and what is it used for? and/or Understanding port forwarding and NAT

[Bunkai.Satori]

+1 and thank you for very good explanation. i will mark this answer as the "accepted answer".

[Jim G.]

Zhenxiao, normally you would specify a specific port or range of ports, but you can NAT all traffic from one IP to another.

[JorgeeFG]

In which case will the IP get replaced? Because I have an exposed server in port 80 (im not the router's administrator) but the IP the log has is the gateway one. So I don't see the real IP of the request

[barlop]

-1 What about NAPT? can you explain if NAPT is NAT with port forwarding? You've said that PAT is Port Forwarding, so that'd mean that NAPT is not NAT and that is false or very unclear at best.

[Nikhil Girraj]

I believe port forwarding and PAT are not the same.