title: Multicast from docker to host's eth
body: <p>currently i am trying to send some multicast data from my docker's application throughout my host's eth2 host interface. i did use <code>--net=host</code> option in docker and this was working perfectly, and unfortunately since i need to open multiple instances that uses same port, its impossible for me to use net=host anymore. i have to go through the <code>bridged</code> mode of <code>docker0</code></p>
  
  <p>in my docker's interface i have <code>eth0</code> which is linked to my <code>docker0</code> as
  10.101.131.60.</p>
  
  <p>therefore i did : <code>route add -net 225.1.1.0/28 dev eth0</code> to pass all multicast packets that my app send to 225.1.1.0/28 to my eth0, which is connected to host as <code>docker0</code>.</p>
  
  <p>therefore, i used wireshark to listen whether my application really throws the message packet to my <code>eth0</code> inside container, and it really does sending multicasts when i use wireshark inside container.</p>
  
  <p>now throughout i also used wireshark to listen to my <code>docker0</code> and the packets were there. Now how do i "Forward all my multicast packets" throughout docker0 to my eth2? i used several iptables approach, but none of them seemed to be useful, perhaps that its being ignored?</p>
  
  <p>any help would be appreciated... thanks!</p>