Ways to find out source of a HTTP request?

Question

What are the various ways through which I can find out the source from which a HTTP request is generated? I know only one, i.e. HTTP referrer field. Is there any other way also?

EDIT: Here I am only interested in knowing that whether the request is generated from a machine directly or from some other website. And in case of some other website, then which one? I am not interested in IP level details.

Answer 1

Correct answer is "Nope​​​​​​​​​​​​. – SLaks♦ Oct 31 at 17:34"