@Arkandel said in Tracking Alts on Dynamic IPs:
I don't know how IP matching possibly works in large cities where most people subscribe to a tiny number of ISPs. In Toronto other than a handful of techies I know almost everyone's either using Rogers or Bell, and all it takes to change your dynamic IP is turn your modem off and on again.
Most of these larger ISP's and back-end tiers lease subnets of their larger subnets to these smaller ISP's.
With some small amount of digging around, you can get the subnets for these tiny ISP's and block those specific ISP's and not the larger subnets.
A few exceptions are china ISP's where a lot of their information is hidden behind the great wall of china, where a lot of times you have to block entire A-class addresses if someone's being a turd and trying to attack your site as their subnet information is obfuscated.
But generally you're pretty good by blocking based on the subnet lookups you can find of any given ISP.
For those who try to hide using proxies, you can get most of the IP lists of the most common proxies and even have dynamic methods to block the more nefarious proxies like TOR with some hardcode mods.
There's always ways around things, but it boils down to what level of restriction you want. The more you tighten, the more chance of impacting innocents. So you have to weigh every choice you do.