There is quite a few examples to RECEIVE multicast messages with a spcific network interface (NIC, e.g. eth0, 127.0.0.1 etc). However, there is few discussion/examples about how to SEND multicast (UDP) messages to a specific interface, e.g. local loop (127.0.0.1) instead of eth0 by default.
Background: RedHat Linux, Python, 224.1.1.1 5005
Python Code example in Multicast in Python
A similar discuss for IPv6 How to send multicast packets via a specfic interface in Linux
A similar discuss for Windows How to Multicast (send) to first NIC?
Thanks in advance.