Is there an on-line service that will tell you if a given IP is a known VPN / proxy? I know that scamalytics seems to do this, I'm just not sure how comprehensive their database or methods are for this.
I'm talking about IP's that are not assigned to the usual suspects. I'm talking about IP's that might be sub-assigned by residential or commercial ISP's.
If I'm sufficiently curious I'll hit the IP on port 80 or 443 and see if anything's there. Is there a more reliable or effective way (ie what port?) to do your own proxy / VPN test?
