Hi,
I first set up the second ethernet port on the server on which Rock is located to the setting described (using the web page). I then changed the network settings on my RaspberryPi, which has the DietPi distribution, using also those same settings (fixed ip address…). Plugged an l’an cable from the second ethernet port of the server to the ethernet port of the Pi and it works. Only issue now is you can no longer access the player (RaspberryPi)…
Hope that helps,
Stephane
Edit: both the IP on the server and player are fixed, but they need to be different