Hostfilterbypass.com
Accept-Encodingx-gzip, gzip, deflate
User-AgentCCBot/2.0 (http://commoncrawl.org/faq/)
Accepttext/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8

The above information can help you determine how well your proxy or VPN is working.
Pay special attention to the User-Agent header which, if everything is set up correctly, should be different from yours.