Basic Checks:

(Header Analysis)

(Header Breakdown: Software)

(Header Breakdown: IP address chain)

Your browser sends HTTP headers to the server. Proxy servers may remove some and add others. This is a passive check that uses only information you are already sending. Visible Software and IP addresses seen are extracted from the headers as well.

(Reverse DNS lookup)

A reverse DNS lookup is done on your final IP address to obtain a hostname. This is an active check but not an unusual one.

(Tor Detection)

This is an active check. It detects if your visible IP address is a Tor exit node.

(Ipredator Detection)

This is a passive check. It detects if you are using the Ipredator VPN service.

(Raw HTTP Headers)

This is a dump of the raw headers received by the server for your request.

("Do not track" Setting)

"Do not track" is an optional header that may be set by your browser.

(Geo Location)

Geo Location is done by comparing your visible IP address against a local Geo Location database. This is a passive check.

Advanced Checks:

(DNS Server Check)

This is a passive test. A custom URL is genenerated for your test and all DNS servers that resolve that URL are noted and displayed.

(Reverse TTL check)

This one is magic. It is a passive test, it reveals the largest minimum TTL required for TCP packets to travel between our server and the requesting host.

(Form Data Check)

In some situations, proxy software is configured to treat requests differently if they contain submitted form information. This check compares a blank request against a form submission and displays any differences.

(Port Check)

This is an active check. During the test our server reaches out and tries a few known proxy ports on the requesting IP. If they are open, it then tries to submit an http request and displays the results.

(Reverse Traceroute)

This is an active check. Our server performs a traceroute to the requesting IP.

IPv6:

Many tests are also available in IPv6 mode. In order for this to function your Internet connection must be IPv6 enabled.