How to troubleshoot the loss of Proxmox home network connection

[thusband]

I lost my network connection for Proxmox after I accidentally disconnected the USB connection for a Coral accelerator. When I plugged it back in the connection was lost.

I have Home Assistant along with Frigate (network video recorder) in a Proxmox VM on an Intel NUC. The Coral is connected via USB. I can hook up a monitor and keyboard to the NUC and access Proxmox root so I guess the NUC is OK but my experience with the terminal command line troubleshooting is pretty limited. I replaced the Ethernet cable from the NUC to my router but nothing changed. The Proxmox NUC had a static IP address and I see it in the static IP listings in the router but it doesn't show as connected in the router. I finally reinstalled Proxmox (I wanted to put Frigate in a container anyway) but nothing changed. Now I'm not sure what I need to do next to troubleshoot the lost network connection.

Any pointers greatly appreciated.

 

[leesteken]

It's this more or less the same question as you asked before: https://forum.proxmox.com/threads/c...-accidentally-disconnecting-usb-coral.136605/ ?
Troubleshooting a network connection issues is very similar to all those threads about not being able to reach the Proxmox web GUI: please login with a physical keyboard and display and show a photo of the output of ip a and cat /etc/network/interfaces.

 

[thusband]

Yes, this is a continuation. After I reinstalled and couldn't connect I thought I might have a different problem. Now, however, I can't explain it but I can now connect to the web GUI. I reconnected the keyboard and monitor to get into root to get the output of ip a and cat /etc/network/interfaces and tried the IP address again for the heck of it. This time it connected to the web GUI! I'm not understanding why I couldn't get in before.

Here's a photo of the output anyway. Does everything look OK?

Many thanks for your patience and help.

 

[leesteken]

Yes, this is a continuation. After I reinstalled and couldn't connect I thought I might have a different problem. Now, however, I can't explain it but I can now connect to the web GUI. I reconnected the keyboard and monitor to get into root to get the output of ip a and cat /etc/network/interfaces and tried the IP address again for the heck of it. This time it connected to the web GUI! I'm not understanding why I couldn't get in before.

Here's a photo of the output anyway. Does everything look OK?

Many thanks for your patience and help.
View attachment 58787

It looks fine but you now don't have the problem anymore, so it's hard to say what was wrong.