Hello, assemblerists!

Now I write the program - the scanner of public proxies. I would like to learn, how it is better to determine, whether the exchange via HTTP protocol is supported by given IP-address? And if the exchange is supported, whether that is given server (IP:port) is a public proxy-server?

Yours faithfully, Dmitry.
Posted on 2002-03-21 04:22:32 by Dmitry V. Zhadan
You could connect using the standard port 8080 most proxies use (some just 80), request some website and see if the response is a valid http response. If you ask for a website which is not on that server and it does return that website, it must be a proxy.

However how and which IPs do you want to scan for being proxy servers? I don't think random portscanning is legal.

Thomas
Posted on 2002-03-21 09:37:24 by Thomas
Hello, M-r Moderator!

Thank you for the answer. The problem was solved very simply - at all how I thought.
> You could connect using the standard port 8080 most proxies
> use (some just 80), request some website and see if the
> response is a valid http response. If you ask for a website
> which is not on that server and it does return that website, it
> must be a proxy.
Some HTTP public proxies works via ports 3128,8000,8888.
> However how and which IPs do you want to scan for being
> proxy servers? I don't think random portscanning is legal.
Some servers, working via HTTP and FTP protocols, send the content only to the users who are taking place within the country where there is a server. The majority of such servers is in Russia and China (and some in USA, Canada, Europe).
Some HTTP servers in Russia is artificially limit speed of proceeding traffic for the non-Russian users. (for example, many Web-sites based on newmail.ru provider).
Both in the first, and in the second case the problem is solved with connection through a public proxy in the necessary country.
Lists of public proxies existing in the Internet are updated extremely irregularly, and do not correspond to true on 99 %.
The software similar to mine, are sold on the lawful base. It's IP-Tools software (the general purpose scanner), and the Advanced Adminstrative Tools software (the scanner of public and anonymous proxies under the user's list).
> Thomas

Dmitry.
Posted on 2002-03-24 05:02:25 by Dmitry V. Zhadan