Watching UDP Multicast Stream on Linux

1. Configure a network interface to use a proper version of IGMP.
2. Add a routing entry to the routing table:
   

   # ip route add 224.0.0.0/4 dev eth0
   

   
   You can add a routing entry by initsctipts:
   

   $ cat /etc/sysconfig/network-scripts/route-eth0
   224.0.0.0/4 dev eth0
   
   # ifup eth0
   
   # ip route show | grep 224
   224.0.0.0/4 dev eth0  scope link
   

3. Configure iptables:
   

   # iptables -A INPUT -i eth0 -d 224.0.0.0/4 -j ACCEPT
   # iptables -A OUTPUT -o eth0 -d 224.0.0.0/4 -j ACCEPT
   

4. Watch an UDP multicast stream:
   

   $ mplayer udp://239.255.128.1:1234
   $ vlc udp://@239.255.128.1:1234