If you have a spare 'dumb' switch around, you could see if that brings the ID41 to life.

In which case, it is possibly a config issue on the switch (I believe Roon finds the ID41 using mDNS, which requires multicast broadcasting to be enabled and it is possible on an intelligent, level 2/3 switch to do all sorts of things that would prevent that from working - although a complete factory reset should turn the Cisco into dumb mode again, with the potential to be configured to do more intelligent stuff).

On USB not working, I've experienced this, as has at least one other member very recently, but with different causes. In my case, it was a blown chip on the card, in the other I seem to recall it was a config issue on the processor (a search for posts on the USB this year should throw up a result).

Prolific music listener / Hi-Fi addict!