Who is your internet service provider?
MonkeyBrains, San Francisco
Please list the make and model of your modem and router?
Apple Airport Extreme
Do you have any additional network hardware, like additional routers or managed switches?
No
Does your network have any VPNs, proxy servers, or enterprise-grade security?
No
Connected Audio Devices
Description of Issue -
What is the exact port forwarding error message you see in the Roon Settings → ARC tab?
Roon Settings → ARC tab says Ready
(I had to manually configure a port forward as described in your installation instructions, there was an error until I did that)
I’ve downloaded roon ARC on my android phone, and signed in, and clicked the Connect button (it says my core was last seen an hour ago), and it just spins.
In addition to the Airport Extreme, do you have any other network devices, i.e., what connects to the Airport WAN socket?
Incidently, you should upgrade your core to either Ubuntu 20.04 or 22.04 LTS, since the version you are running is no longer supported nor receives security updates.
No other devices. A restart of roon this morning fixed things. I am beginning to suspect it was not running during my distress call.
BTW, for a trip down the rabbit hole, try to find anything actionable in support docs about
verifying that roon is running on your linux box. Everything I encountered did a vague
hand-wave about exactly what you might do. I ended up grepping ps output.