Question

I’ve been looking around to find a way to have SocketServer python module to listen on multicast without success.

Anyone managed to do so ?

Any insight will be greatly appreciated !

Thanks

Answer 1

The docs (http://docs.python.org/library/socketserver.html) don’t make any mention about multicast, and the source code (http://hg.python.org/cpython/file/2.7/Lib/SocketServer.py) doesn’t set any socket options you’d expect to see in a multicast listener (e.g. socket.IP_ADD_MEMBERSHIP), so I’d say SocketServer doesn’t support multicast.

I assume (you should try to include a code snippet with the error you’re getting) you’re trying to make a UDPServer and you’re getting an error that is something like:

socket.error: [Errno 10049] The requested address is not valid in its context

This is because UDPServer is a subclass of TCPServer, and when a TCPServer is created it calls bind() on the specified address. You’re not supposed to bind to a multicast address for listening though (hence the error), you use the IP_ADD_MEMBERSHIP socket option to listen for multicast traffic.

Looks like you may have to roll your own multicast server.