I use IE 9 with socks in order to connect to a socks4 server (IE does not support socks5)
The socks4 specifies that a socks4 client has the possibility/obligation(?) – specification – to indicate in the SOCKS4 request message a variable length userID field (after specifying at CONNECT version, command, dest port and dest ip fields)
I didn’t find that information (userId) when using IE 9.
Is there a way that could make IE send USERID information ?
The only way IE sends userId information is when the user is part of an active directory domain. This is at least what I saw while testing.