Suggestion/Opinion on Reverse IP look up for Anonymour proxies

Question

Sometimes it is not possible to find if user is using Anonymous proxy. So i came up with some ideas:

Get IP of client, do reverse check and check if it returns a hostname and also get number of any websites hosted on same ip then it could be a proxy connection assuming it is website hosting provider ip. Store ips of hosting providers which allow proxy hosting and query them to check if IP matches and block them. So guys do you think this technique is possible or might work to some extent?

I know these are not best solutions. I'm not a expert but a newbie, please do correct me if i mentioned something wrong or something is technically incorrect.

Answer 1

I Think the idea has some merit but is alot of leg work and really not maintainable.

Finding out if the ip address has a hostname really wont help as lot of ISP's assign hostnames to peoples home connections that have static IP's (like mine does)

You could check against a list of known hosts that allow proxies but you do run the risk of blocking out legitimate traffic, I know that there are services that provide lists of proxy websites that are used to block them out at DNS level (using applications like squid) so you may be able to use that data to check against but im not 100% sure on that