The current multi-functions routers generally promulgate the dynamically obtained IP by their administration http web page, and pop up a user’s name and password verification window before the administration page. To automatically respond to the user’s name and password verification and get the promulgated IP ,the WinInet library is needed.WinInet library is the extended interface of Win32 Internet which is provided by MFC.By WinInet,the location difference of INTERNET data is masked, then INTERNET data can be stored and retrieved as conveniently as local data. The common WinInet classes include CInternetSession, CHttpFile,CHttpConnection, and so on.The steps of obtaining dynamic IP from the router’s page by WinInet classes are as follows