Down for a while, the Frost Jedi Open Proxy Detector is back up! A few improvements have been made and more on the way. Work on
the phpBB mod inspired by this page -
Block Open Proxy Registrants -
will resume soon, too.
As defined by
RFC 2068, a proxy is "an intermediary program which
acts as both a server and a client for the purpose of making requests on behalf of other clients." RFC 2068 continues,
"requests are serviced internally or by passing them on, with possible translation, to other servers. A proxy must
implement both the client and server requirements of this specification."
The type of a proxy is determined by, among other things, the amount of information that the proxy reveals about the
person using it. For example, transparent proxies add, to their HTTP requests, one of two HTTP headers - VIA or
PROXY_CONNECTION - that are unique to proxies, and another HTTP header - X_FOWARDED_FOR - from which the original IP
address can be determined. In contrast, Anonymous proxies, lack the X_FOWARDED_FOR header. High Anonymity proxies
(also known as Elite proxies), unlike Anonymous proxies, can't be identified at all as proxies from their HTTP
requests at all (ie. their requests don't include any of the three afore mentioned HTTP headers). A proxy which
sends out HTTP requests from a different IP address than the ones it recevies them from is known as a Gateway proxy.