Rebooted switches (managed netgear GS116 and Cisco SLM2008) → at first no success, but after restarting Roon two times, I’ve got a connection an now it seems to run.
But: What was the cause for the problem? I’m running Roon since today over a year without problem.
My guess is missing multicast packets. Routers exhibiting this after a few months is not uncommon. People find it hard to believe their network infrastructure is buggy because web browsing works normally even if multicast fails.
Yes, it must be something in this area.
In former times, I’ve used some VLANs for a video multicasting system and I’ve that I’d removed the special settings for it on all my managed switches.
Have to check all my managed switches settings.