Is it plugged in?

I couldn't ssh to my Arch Linux Arm that's installed on a Raspberry Pi in my office at work yesterday. Fortunately it's not a million miles away, which is normally the case when you use ssh to control a remote system, so I logged into it locally (Sat down in front of it) and did
$ ifconfig
Now some of you will know that the new hipster command is in fact $ ip addr but I'm old school, bite me. :-)

image source

The Raspberry Pi was giving me whats know as an ipv6 address. As an example it's generally in the format 2001:0db8:85a3:0000:0000:8a2e:0370:7334 rather than something along the lines of 192.168.1.21 which is ipv4 the thing is, ipv4 effectively cannot talk to ipv6 as they are separate layers. (There is a workaround, but I'm not going into that here.)

Now this was weird? Everything was fine last week so what had happened? At this stage, I suspected an update that I'd applied and so headed off down the path of convincing the machine that it should, in fact, use ipv4 by editing the network configuration. After several attempts and a couple of reinstallations of the operating system, I decided to vent my spleen on my Mastodon account with my good friend and fellow Arch Linux user @theru

Now don't ask me why but I decided to check something. The Rasberry Pi uses a 48" TV on the wall in my office for its display. I also have a Small Form Factor (Windows 10 ) PC attached to it as well. I switched to the Windows PC and 'Bingo!' that also was having a network issue. Demanding that one of my Engineers "Get in here!" we start to trace the spaghetti that is the network cables in my room.

@theru I love you you horrible man. LOL