http://bugs.winehq.org/show_bug.cgi?id=5800
------- Additional Comments From mike@codeweavers.com 2006-31-07 03:09 -------
InternetCheckConnection is at: wine/dlls/wininet/internet.c # 2766
I'd advise you to use InternetOpenConnection, and not try to guess the server/port to connect to yourself.
Hans's suggestion to do investigate what Windows does is a good one too. Maybe use ethereal?