I have a unmanaged c++ application that also runs on Mac/Linux/Soalris. Since I moved to Windows7 x64 RC (I was on Vista x64 before) my program stopped working. After some debugging it looks like I have to explicitly specify which interface I need to bind with. If I specify INADDR_ANY it does not work. Would this be a network driver issue (Intel (R) WiFi Link 5100AGN version 12.4.1.4 date 3/26/2009) or is this a Windoes issue?Here are general steps that I am takingm_socket = socket( AF_INET, SOCK_DGRAM, 0);//IPPROTO_UDP); unsigned int on(1); int ret = setsockopt(m_socket, SOL_SOCKET, SO_REUSEADDR, (SETOPTCAST)(&on), sizeof(on) ); memset( (void*)&m_servaddr, 0, sizeof(m_servaddr) ); m_servaddr.sin_family= AF_INET;m_servaddr.sin_port= htons( m_port ); m_servaddr.sin_addr.s_addr= htonl( INADDR_ANY );// Does not work//m_servaddr.sin_addr.s_addr= inet_addr( "192.168.0.99") ); // Works int ret = bind(m_socket, (SOCKADDR*)&m_servaddr, sizeof(m_servaddr)); // No Error here on both cases mreq.imr_multiaddr.s_addr = inet_addr( mcgroup.c_str() ); mreq.imr_interface.s_addr = htonl(INADDR_ANY );// Does not workmreq.imr_interface.s_addr = inet_addr( "192.168.0.99") ); // Works setsockopt(m_socket, IPPROTO_IP, IP_ADD_MEMBERSHIP, (SETOPTCAST)(&mreq), sizeof(mreq)); when I try to read I block for ever (INADDR_ANY) or works when local IF specifiedCheersRobert

Hi Robert: You'd find more help for this question at the MSDN Developer forums. This forum isn't meant for discussion of development issues. Best of luck, Nick

I understand. But it sure looks like this is a problem with Windows 7. Since the same code with out any changes does work on Vista x32. x64 as well XP. (including linux mac and solaris)