For exam this site http://check.getipintel.net/check.php?ip=IP_address takes IP address as a get ip parameter's value and returnd the likelyhood of it being proxy.
For example, I'm using a proxy on purpose to see what it returns.
http://check.getipintel.net/check.php?ip=166.62.97.241
If it returns 1, it's definitely a proxy, if it returns 0, it's a regular address and if it returns something in middle, for example, 0.08 there's chances it's a proxy too! and what about 0.5? right! we really cant tell in that case.
Good part about it is you can check user for proxy in your applications and take a decision whether to allow him or not.
You can read more about it on their offical website
http://getipintel.net/
Update. Thanks to Stewart for adding good reason why you'd want to use it.
1 - Protect your site from automated XSS / SQL Injection / Brute Force / Crawlers that steal your content -- Well that's just a load of crock since they don't use proxies. Also hackers tend to go via infected computers and not proxies
2 - Serve traffic / content to real users, not bots, which reduces server load (bot detection) -- Again bots run from their own servers not via proxies
3 - Stop bots from scraping your content or bots spamming your website -- See the previous two responses
4 - Prevent trolls / people that are trying to bypass a ban -- True but then it doesn't stop dynamic IP address allocation nor just going to shops and using the countless free WiFi spots available
5 - Greatly reduce fraud on e-commerce sites (anti-fraud) -- Again not really
The site also has bad IP detection, which looks for compromised systems that are involved in web based attacks. If a user starts a web based attack on their own IP, then the system admin has enough information to proceed with further legal action. Thus, comments for 1, 2, 3, and 5 are not exactly true. The system does more than just proxy detection, which is fully described on the website.
ReplyDeleteAs for 4, the system also does partial detection for public networks. If a user has a dynamic IP, then they are constricted to a particular network which means they're a lot easier to find and deal with. This particular technique can be used for all systems that does proxy detection or even fraud detection. It is not an exclusive issue to GetIPIntel.