How to find why network suddenly stops working on my Proxmox?

[Arctica67]

I'm new to Proxmox. I installed it on a Lenovo ThinkCentre M90Q with 32 GB RAM some 2 weeks ago. Installation went fine with 9.0.11 running. Continued with a VM running Home Assistant, also no problem at all. Fixed IP on both Proxmox host and the Debian VM running Home Assistant. It's been running without any problems for 2 weeks.

The problem:
Yesterday, at work, I suddenly noticed that I could not connect to neither Home Assistant nor Proxmox. When PING'ing their IP addresses I didn't get response. "OK", I thought, "It's probably easy to see what the problem is when I get home"
So, I get home, and then it is a bit more weird. I hook up a monitor and a keyboard to the machine. And I have the login prompt and can login physically to the Proxmox machine. I am not so familiar with Debian/Linux, so I try some extremely basic things. I can PING 127.0.0.1 obviously. But if I PING anything else, like 8.8.8.8 or even the local networks gateway, I get no response. Same thing (of course) with trace route.
So, something has happened with the network connectivity. But what? Anyway, a reboot made everything work again and I thought that this will be one of those weird "if it happens once and never again - just ignore it". But now, only some 8 hours again, it has happened again.

The question:
How do I troubleshoot this? Which logs would tell me what the problem is? I don't think it is a hardware problem as such, the machine is brand new, and I have installed hundreds of them at work and never had any hardware issues with the NIC ever (We are using them at work with Windows). But of course, Murphy's law is never far away to come into play. But any help in the right direction is most helpful as its most probably a beginner's configuration error that is the reason.

 

[Arctica67]

I guess I should have investigated a bit more myself before reverting to ask for help in the forum
I found this in the proxmox log window:

Oct 29 06:08:15 proxmox1 kernel: e1000e 0000:80:1f.6 enp128s31f6: Detected Hardware Unit Hang:  TDH                  <23>  TDT                  <80>  next_to_use          <80>  next_to_clean        <22>buffer_info[next_to_clean]:  time_stamp           <102868335>  next_to_watch        <23>  jiffies              <102b18e40>  next_to_watch.status <0>MAC Status             <80083>PHY Status             <796d>PHY 1000BASE-T Status  <3800>PHY Extended Status    <3000>PCI Status             <10>

Now I only need help with how to rectify the hardware hanging, I will google and ChatGPT search it of course, but appreciate a lot of someone has any suggestion. Thanks!

Actually, I might already have found the solution by reading this thread:

https://www.reddit.com/r/Proxmox/comments/1drs89s/intel_nic_e1000e_hardware_unit_hang/

Sorry if I wasted people's time. but at least maybe someone else with same problem might benefit from same solution.

 

[Onslow]

Welcome, @Arctica67 !
If the solution has worked for you, I suggest you describe it (quote it) in this thread. So that the info doesn't depend on outer links which may vanish some day, as it happened too many times in the Internet history ;-(.

Then you may edit (I think) the topic of the thread (add "Intel e1000e") and prefix it with "[SOLVED]" from the drop-down menu. Thanks!

 

[Arctica67]

Welcome, @Arctica67 !
If the solution has worked for you, I suggest you describe it (quote it) in this thread. So that the info doesn't depend on outer links which may vanish some day, as it happened too many times in the Internet history ;-(.

Then you may edit (I think) the topic of the thread (add "Intel e1000e") and prefix it with "[SOLVED]" from the drop-down menu. Thanks!

Good advice. Let me have the system run for a couple of days. If it works without any problems I will update as you say. Thanks!