[arch-general] Linux server crash causing router switch to stop working

[Andy Pieters]

On Mon, 24 Jan 2022 at 15:50, Genes Lists via arch-general <
arch-general at lists.archlinux.org> wrote:

>
> > It's hard to know for sure exactly what's happening, as the server is
> > headless.  It does have a KVM-over-IP hooked up to it, though.  But when
> > Perhaps you can login after server is back and look at journal spanning
> period before and after the problem (e.g. journalctl --since -2h).
>

There is a kernel module that enabled kernel log to be sent over network
[1] but the described problem has all the flavour of a hardware issue. I'd
try replacing the LAN cable between server and router first, and if at all
possible the network card as well..

If that's not possible, try running tcpdump on another machine and have it
capture in promiscuous mode. After a crash you can load the saved pcap file
into wireshark GUI and inspect for clues (apologies if you're a lemon
farmer and I'm teaching you how to juice lemons)

[1] https://wiki.ubuntu.com/Kernel/Netconsole