This means that the operating system is responsible for forwarding traffic to other programs or sockets on the same host that joined a multicast group, since it won't be read from the interface. On the hardware level, multicast traffic is treated like broadcast traffic in that it is not routed back to the physical port it was sent from in order to prevent link level loops. It is difficult to search for this problem specifically with regards to operating system behavior or standardization. This is quite a common question with many StackOverflow questions on it, but they are often misunderstood or poorly worded. The real problem is having programs on the same host receive multicast data sent by each other (or, equivalently, having sockets within a single program receive multicast data sent by each other), when they're both configured to use the same multicast group. However, this is typically only necessary if there are other computers on the network that may interfere by using the same multicast group. Transmit_file(argv,argv,INTERFACE_IP,UDP_PORT) īinding or routing to the loopback device is necessary if you do not want IP multicast traffic (such as IGMP messages) to be sent across the network. I have already tried following commands sudo ifconfig lo multicastĪny suggestion in this regard would be very helpful. I'm able to see packet getting transmitted in wireshark but the src ip is taken from my default network interface (i.e interface which is my default gateway)

But when tried to play the same on vlc it didn't worked. Leaving aside other bitrate and controlled multicast issues, I tried to read one video file and multicast on loopback device. The idea is to receive a video stream via RTSP/HTTP or any other network protocol and multicast it on the loopback address so that I can use VLC to play the stream using multicast address. I wish to send UDP multicast packets to loopback address and receive the same in other application.

Indirection in ip multicast