Destination host unreachable forcing to shutdown

[jramos]

Hello.

I have a very strange behavior with my Proxmox. From time to time, I lose connection to Proxmox. That happened to me yesterday and today but today I had a ping running with the following output:

 ping -t 192.168.1.104

Reply from 192.168.1.104: bytes=32 time=13ms TTL=64
Reply from 192.168.1.104: bytes=32 time=5ms TTL=64
Reply from 192.168.1.104: bytes=32 time=7ms TTL=64
Reply from 192.168.1.104: bytes=32 time=4ms TTL=64
Reply from 192.168.1.104: bytes=32 time=5ms TTL=64
Reply from 192.168.1.104: bytes=32 time=4ms TTL=64
Reply from 192.168.1.104: bytes=32 time=4ms TTL=64
Reply from 192.168.1.104: bytes=32 time=44ms TTL=64
Reply from 192.168.1.104: bytes=32 time=7ms TTL=64
Request timed out.
Request timed out.
Reply from 192.168.1.121: Destination host unreachable.
Request timed out.
Reply from 192.168.1.121: Destination host unreachable.
Reply from 192.168.1.121: Destination host unreachable.
Reply from 192.168.1.121: Destination host unreachable.
Reply from 192.168.1.121: Destination host unreachable.
Reply from 192.168.1.121: Destination host unreachable.
Reply from 192.168.1.121: Destination host unreachable.
Reply from 192.168.1.121: Destination host unreachable.
Reply from 192.168.1.121: Destination host unreachable.
Request timed out.
Reply from 192.168.1.121: Destination host unreachable.
Reply from 192.168.1.121: Destination host unreachable.
Reply from 192.168.1.121: Destination host unreachable.
Reply from 192.168.1.121: Destination host unreachable.
Reply from 192.168.1.121: Destination host unreachable.
Request timed out.
Request timed out.
Request timed out.
Request timed out.
Reply from 192.168.1.121: Destination host unreachable.
Reply from 192.168.1.121: Destination host unreachable.
Reply from 192.168.1.121: Destination host unreachable.

When this happens, I don't have any other way than just force a shutdown by pressing the button.

HW info

CPU(s) 6 x Intel(R) Core(TM) i5-9500 CPU @ 3.00GHz (1 Socket)
Kernel Version Linux 6.8.12-11-pve (2025-05-22T09:39Z)
Boot Mode EFI
Manager Version pve-manager/8.4.1/2a5fa54a8503f96d

Are there any logs that I could check for the problem?

 

[Hannes Laimer]

Hey,

definitely check journalctl -b (-b for since last boot). dmesg may also contain something useful. What does your /etc/network/interfaces look like? And could you post the output of ip a? Is it only the host, or are VMs also not reachable?