There are numerous recommendations to ban proxy connections like:
#RewriteCond %{HTTP:USERAGENT_VIA} !^$ [OR]
#RewriteCond %{HTTP:VIA} !^$ [OR]
#RewriteCond %{HTTP:HTTP_PC_REMOTE_ADDR} !^$ [OR]
#RewriteCond %{HTTP:HTTP_CLIENT_IP} !^$ [OR]
etc.
What I canīt find is a comprehensive description, what these connections practically mean and how they are in use. If the complete list is set on, it depending on browser happens, that a favicon.ico is no longer displayed, because the browser uses to fetch it via a proxy sideline (=Firefox). Another occurance is, that if a webpage is called and left alone for a while and then refreshed, the browser complains something like "lost connection".
In addition I found, that proxies are not as often given either an additional optional service in companies or serving spamming otherwise. In some cases they seem to be the only solution of people in censoring countries (typically Near East). Massive advertising of banning any proxy connections obviously can serve censoring aims.
Undoubtfully lots of hacks and exploits solely run via proxy connections for obvious reasons. So clever setup of these rules remains desirable.
Is there some more detailed information on these proxy-channels that allows a closer taylored solution for own setups?
