c# - How do I get the correct IP from HTTP_X_FORWARDED_FOR if it contains multiple IP Addresses?

Question

If Request.ServerVariables["HTTP_X_FORWARDED_FOR"] returns multiple ip's, which one do I take and how would I do it in c#? It is my understanding that if it is blank or null, then the client computer is not going through a proxy and I can just get their ip from Request.ServerVariables["REMOTE_ADDR"]. Is this a correct statement?

By "which one do I take", I mean do I take the first IP in the list or the last IP and is all I have to do is just split it into an array and take the one I want. I am not really sure how HTTP_X_FORWARDED_FOR works.

Answer 1

According to this, the format of X-Forwarded-For HTTP header is:

X-Forwarded-For: client1, proxy1, proxy2, ...

So the IP address of the client that you want should be the first one in the list