Arduino UNO ethernet shield2 + Multicasting

Hello I wonder if there is a tutorial(s) or somebody who can explain to me how I do multicast in the Arduino IDE.

I like to send one command ex. "hello" to multiple computers with the same python script and let them receive this message "hello".

Is there anyone who can help me on this one ?

Thanks in advanced

...R

I don't have a lot of experience with this myself but it seems like you must use UDP to broadcast a message over the local network. TCP/IP messages can only ever go to one address.

UDP doesn't propagate outside a local network, so if your computers are on different networks or the internet you will need to do more work.

Yes, UDP multicast is quite easy within a network.

For TCP, you need at least one PC to act as a server, then re-broadcast messages to connected clients.

Hi thanks for your replies.

It is in a LAN network ( it always will ). I never use the TCP protocol.

UPDATE : I found Ethernet3 library wich support multicast ( W5500 ) but there doesn't seem to be any tutorials except for the source files ofcourse.

https://github.com/sstaub/Ethernet3

I found some code here http://blog.roeften.com/2015/03/multicast-communications-between.html but I haven't tried it.