Assume that we have 2 pc on the same LAN,
local IP of pc1:
local IP of pc2:
Now suppose that both pc1 and pc2 wants to connect to a server on the internet,
we all know that the server will receive 2 requests from the same IP which is the public IP (let us say it is
192.168.1.6 are private, and for that, we have port numbers.
So the server will receive 2 combinations of (
IP, source port number);
let us say they are : (
18.104.22.168, 3455) and (
Now the question is, what will guarantee that pc1 and pc2 will not use the same source port number, then the server will get confused?