A client sends a request (what files he wants) and a server sends a response (mandatory files). These records can be crucial for the server so that you can understand which webpage should be given (open) to the client. There are distinct versions of web pages for different arrangements of browsers. Nevertheless, provided that web pages don’t generally rely on browsers, it’s wise to conceal these details from your web server.
What your browser transmits to your webserver:
a name and a variant of an operating system
a name and a variant of a browser
IP address of a client
Other info
The most significant part of such advice (and totally useless for a web server) is advice about IP address. Using your IP it’s not impossible to understand the following:
a state where you’re from
a city
your supplier’s name and email
your real address
Info transmitted by a client to your server is available (reachable) for a server as environment variables. Every advice unit is a value of some variant.
REMOTE_ADDR ? IP address of a customer
HTTP_VIA ? Then a proxy can be used if it’s full.
HTTP_X_FORWARDED_FOR ? Then a proxy can be used if it’s full. Value is a genuine IP address of a customer (your IP), this variant can also be added by a proxy server if you use one.
HTTP_TAKE_LANGUAGE ? what language can be used in browser (what language a page should be shown in)
HTTP_USER_REPRESENTATIVE ? so called “an user?s representative”. This is Mozilla.
HTTP_HOST ? is a webserver name
This can be a little part of environment variables. Actually there are considerably more of them (DOC_ROOT, HTTP_TAKE_ENCODING, HTTP_CACHE_CONTROL, HTTP_CONNECTION, SERVER_ADDR, SERVER_SOFTWARE, SERVER_PROTOCOL, …). Their amount can be determined by settings of a client and a server.
These are instances of values that are varying:
HTTP_TAKE_LANGUAGE = ru
HTTP_USER_AGENT = Mozilla/4.0 (compatible; MSIE 5.0; Windows 98)
HTTP_HOST = www.webserver.ru
HTTP_VIA = 196.25.1.1 (Squid/2.4.STABLE7)
Anonymity on the job in Internet is based on what environment variables “hide” from a webserver.
In case a proxy server just isn’t used, then environment variables appear in the next manner:
DISTANT_ADDR = your IP
HTTP_VIA = not ascertained
HTTP_X_FORWARDED_FOR = not ascertained
Clear Proxies
They don’t conceal details about your IP address:
DISTANT_ADDR = proxy IP
HTTP_X FOR = your IP _FORWARDED_
The function of proxy servers that are such just isn’t the progress of your anonymity in Internet. Their goal is organization of combined use of Internet of several computers, advice cashing, etc.
Anonymous Proxies
All proxy servers, that conceal a client’s IP address in any manner are called anonymous proxies
Straightforward Anonymous Proxies
These proxy servers tend not to conceal a fact that the proxy can be used, however they replace your IP
DISTANT_ADDR = proxy IP
HTTP_X FOR = proxy IP _FORWARDED_
These proxies are the most spread among other anonymous proxy servers.
Distorting Proxies
Together with straightforward anonymous proxy servers these proxies don’t conceal the fact a proxy server can be used.
DISTANT_ADDR = proxy IP
HTTP_X FOR = arbitrary IP address _FORWARDED_
These proxy servers can also be called “high anonymity proxy”. In contrast to other kinds of anonymity proxy servers they conceal a fact of using a proxy:
DISTANT_ADDR = proxy IP
HTTP_VIA = not ascertained
HTTP_X_FORWARDED_FOR = not ascertained
Depending functions there are anonymity and clear proxies. Yet, recall, using proxy servers you conceal just your IP from a web server, but other info (about browser settings) is accessible!