Talker can publish "Hello World" but listener cannot receive about ros2-toolchain-crosscompile HOT 4 CLOSED

route add -net 224.0.0.0 netmask 240.0.0.0 dev lo
ifconfig lo multicast

After running the above cmds, talker/listener demo works. Thanks for your help.

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Are you running the demo on an actual arm64 device? It is important to note that ROS2 multicast communication doesn't work in QEMU.

from ros2-toolchain-crosscompile.

Are you running the demo on an actual arm64 device? It is important to note that ROS2 multicast communication doesn't work in QEMU.

Yes. I run the demo in an actual arm64 device. And the print log of "route -n" is:

Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
224.0.0.0 0.0.0.0 240.0.0.0 U 0 0 0 eth0

I guess it means my arm64 linux kernel support multicast.

from ros2-toolchain-crosscompile.

I'm not sure exactly how to read the output of route -n to tell if multicast is enabled. Does that tell you that it is?

I think if netstat -g has an all-systems.mcast.net output, then it is enabled.

Other than that, I'm not that experienced with debugging network communication issues in ROS2.

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