How Does NAT/PAT Work?
I’ll give you an answer that isn’t simply copy/paste from some random web resource. NAT is a somewhat less commonly implemented than most people think, since what lots of cheap home router manufacturers like to call “NAT” is really PAT. When you have NAT enabled, whenever a machine from your network requests an outside address, say, “10.10.10.10”, your router notes the IP address of the local machine along with the IP address that you’re trying to obtain in a “NAT table”. It then changes the source IP address in the IP packet header (basically, takes the packet of information you’re sending, and changes the information to make it appear like it came from your public internet address), and sends it out on the Internet. Whenever the router receives incoming traffic from the Internet, it takes the addressing information in the IP packet header and looks for a match in your NAT table. If the traffic source (where it came from) is “10.10.10.10”, your router will find a match in the NAT tabl
