Anonymity of Proxy
The exchange of information in Internet is made by the "client - server" model. A client sends a request (what files he needs) and a server sends a reply (required files). For close cooperation (full understanding) between a client and a server the client sends additional information about itself: a version and a name of an operating system, configuration of a browser (including its name and version) etc. This information can be necessary for the server in order to know which web-page should be given (open) to the client. There are different variants of web-pages for different configurations of browsers. However, as long as web-pages do not usually depend on browsers, ...view middle of the document...
Value is a real IP address of a client (your IP), this variable is also added by a proxy server if you use one.
HTTP_ACCEPT_LANGUAGE ? what language is used in browser (what language a page should be displayed in)
HTTP_USER_AGENT ? so called "a user?s agent". For all browsers this is Mozilla. Furthermore, browser?s name and version (e.g. MSIE 5.5) and an operating system (e.g. Windows 98) is also mentioned here.
HTTP_HOST ? is a web server?s name
This is a small part of environment variables. In fact there are much more of them (DOCUMENT_ROOT, HTTP_ACCEPT_ENCODING, HTTP_CACHE_CONTROL, HTTP_CONNECTION, SERVER_ADDR, SERVER_SOFTWARE, SERVER_PROTOCOL, ...). Their quantity can depend on settings of both a server and a client.
These are examples of variable values:
REMOTE_ADDR = 220.127.116.11
HTTP_ACCEPT_LANGUAGE = ru
HTTP_USER_AGENT = Mozilla/4.0 (compatible; MSIE 5.0; Windows 98)
HTTP_HOST = www.webserver.ru
HTTP_VIA = 18.104.22.168 (Squid/2.4.STABLE7)
HTTP_X_FORWARDED_FOR = 22.214.171.124
Anonymity at work in Internet is determined by what environment variables "hide" from a web-server.
If a proxy server is not used, then environment variables look in the following way:
REMOTE_ADDR = your IP
HTTP_VIA = not determined
HTTP_X_FORWARDED_FOR = not determined
According to how environment variables "hided" by proxy servers, there are several types of proxies
They do not hide information about your IP address:
REMOTE_ADDR = proxy IP
HTTP_VIA = proxy IP
HTTP_X_FORWARDED_FOR = your IP