Take the 2-minute tour ×
Server Fault is a question and answer site for system and network administrators. It's 100% free, no registration required.

I'm running Apache 2.2 on a linux box. Is there any reliable way of detecting if a visitor to my website is connecting from a VPN? I've heard of attempting to open a tcp connection on the remote ip address, which can sometimes identify the user as using a proxy. But could the same method work with VPN users?

share|improve this question

2 Answers 2

up vote 5 down vote accepted

Plain and simple - you can't. There are way too many types of VPN, way too many providers, and overall way too many variables here to be able to reliably tell if someone is using a VPN.

share|improve this answer

I doubt it, it would look the same way as if someone was using NAT.

share|improve this answer
You can't even reliably determine yourself if you are using a VPN. –  David Schwartz Mar 13 '12 at 22:30

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.