On 10/03/10 13:03, Ben Barker wrote:
But I seem to have trouble getting them to receive anything at all.
That's a little vague. Does "trouble" mean "it sometimes works" or "never works"?
Sorry - yes, it was very vague! Never works. If I run wiresahrk I can see udp packets addressed to 224.0.0.4, port 901, flying past, however when I run my python script it does not appear to ever receive anything.
The scritp I am running is almost identical to an exampel I found here:
http://code.activestate.com/recipes/425975-simple-udp-multicast-client- server-using-twisted/
I have managed to use tshark to display the packets :
tshark -i eth0 -x -l -f udp
Can you post a complete example that isn't working for you?
When your code is running, have a look "/sbin/ip maddr" to ensure the group has been added to the socket listen filter eth1 link 01:00:5e:00:00:04 link 33:33:ff:7a:7e:4e link 01:00:5e:00:00:fb link 01:00:5e:00:00:01 link 33:33:00:00:00:01 inet 224.0.0.4 inet 224.0.0.251 inet 224.0.0.1 inet6 ff02::1:ff7a:7e4e inet6 ff02::1
That's interesting.... eth1 is the wrong interface! In fact, it isn't connected to anything at all. eth0 is the interface that should be being used. I will try to swap them around, but presumably this is something I can specify somwhere...
Hmm. What does "ip route" say? Do you have 224.0.0.0/4 routed out of eth1 somehow?