http://ntrg.cs.tcd.ie/undergrad/4ba2/multicast/antony/example.html

Make sure that Multicast is enabled in kernel. May need recompiled.

ifconfig, check if interface has “MULTICAST”.

ip route add 224.0.0.0/4 dev wlan0.

disable icmpechoignorebroadcasts: echo 0 > /proc/sys/net/ipv4/icmpechoignorebroadcasts.