I attempted to upgrade my Raspberry Pi 3 (my server) to the latest Debian Stable (Bullseye). But I ran into dependency issues. I'm pretty sure they'd be resolved by themselves if I upgraded. It's just that apt/apt-get/aptitude refuses to upgrade anything as long as I have dependency issues.
That's fine. I should rebuild my config from scratch anyway. I picked my Raspberry Pi 2 out of my electronics box and flashed an SD card with the latest Raspberry Pi OS Lite image. Plugged it into my router. Set a DHCP reservation for it. But then my router lost all ethernet-connected devices.
Okay... Buggy, much? There was a firmware upgrade available. I decided now was a good time to install it, so I did that and rebooted the router. All ethernet connections came back! Victory!
I connected to my Raspberry Pi 2 via SSH. Changed the password of the default user. Saw that the latest image apparently was very old. It still ran Buster. I decided to upgrade it. All went well, but then it was time for bed.
Fast forward a few days and I had time to tinker with it again. Except now it was completely lost from my network. The router wouldn't acknowledge its existence. And when I looked at the Pi the ethernet LEDs weren't blinking at all, and the status LEDs indicated that something was wrong. Maybe an issue with the Pi?
I decided to unplug it and move the SD card to my Raspberry Pi 1 B+ (I have five Raspberry Pis, okay?). Booted it up and plugged the ethernet cable in. The ethernet LEDs were blinking! Yay!
But the router wouldn't acknowledge the existence of this Pi either. Switched the SD card back to the 2 and booted that up. It looks like it's running great now. All LEDs say all is fine. But it's still invisible to the router.
All I wanted was to upgrade a server...
-- CC0 Björn Wärmedal