Detect fake IP address?

Question

How do you know if an IP address for data received via a web form came from a fake IP address?

If discovery is possible in PHP, is there a library that will also try to find the real IP address?

Answer 1

Äh - you cannot. There cannot be a fake IP address.

See, HTTP (which is an encore for web forms) runs on top of TCP.

If I trick my IP address into a TCP process, I will never be able to establish a TCP connection. If you have established a TCP connection, I cannot send data to your server.

- , , ( , ):

Ergo: , TCP-, IP- IP-.

, IP-?