Can't send UDP packet to multicast address. See traceback. s.sendto( bytearray, ("227.5.6.7", 6543)) socket.error: [Errno 10065] A socket operation was attempted to an unreachable host
I tested multicast without any issues using the attached script. I used RC3 on both Windows 7 and Linux. I did need to disable the firewall on my Windows system before multicast would work. Start one or more clients using: "python mtest1.py client" Send data using: "python mtest1.py server hello 10"
Are you using a default gateway ? Are you sure this gateway supports multicast ? See for example http://www.sockets.com/err_lst1.htm#WSAENETUNREACH : """ WSAENETUNREACH (10051) Network is unreachable. Berkeley description: A socket operation was attempted to an unreachable network. WinSock description: Almost same as Berkeley. For WinSock, this error is equivalent to Berkeley's EHOSTUNREACH error, the catch-all error for unreachable hosts. "You can't get there from here." TCP/IP scenario: The local network system could generate this error if there isn't a default route configured. Typically, though, WinSock generates this error when it receives a "host unreachable" ICMP message from a router. The ICMP message means that a router can't forward the IP datagram, possibly because it didn't get a response to the ARP request (which might mean the destination host is down). Note: this error may also result if you are trying to send a multicast packet and the default gateway does not support multicast (check your interface configuration). """ By the way, when you submit this kind of issue, it's a lot easier to analyse if you provide a sample code.
