I'm going to bed, I've had enough. Don't worry @enginewitty if you catch this. I've got the @hivepimp bot running smoothly elsewhere.
Running a home network of Raspberry Pis is like managing a tiny datacenter. Each device has its own role—head node, workers, miners, streamers—and when one goes dark, everything feels out of balance. That’s exactly what happened when I realized my Pi Zero, the little board I use for monitoring all the other servers, had seemingly vanished from the network.
At first, I thought it was a simple ping check. I tried hitting *.208, the address I had reserved for the Pi Zero. Instead of a reply, my system came back with:
Reply from *.151: Destination host unreachable.
That meant my machine could reach the network, but another device (my own gateway interface) was reporting that the host was nowhere to be found. So where did the Pi Zero go?
I dug deeper using arp -a, checking if the MAC address for .215 was cached. Nothing. The address wasn’t being claimed by anything on the LAN. Next up was a full network sweep with nmap -sn *.1.0/24. That revealed all the usual suspects—head node at .205, Pis at .213 and .214, Roku at .184, even some mystery devices at .222 and .223. But .215 was completely absent.
So here I was, staring at an empty ARP table and a clean scan, knowing the Pi Zero had either powered off, slipped onto another subnet, or somehow lost its IP config. It’s a small thing—a single board computer—but it’s the one I rely on to monitor all the other Pis. Without it, I feel like I’m flying blind.
This is the reality of DIY clusters: when everything works, it feels like magic. When one piece disappears, it turns into a hunt. Next step for me is checking the router’s DHCP leases to see if my Pi Zero is still alive under a new address, or if it’s time to pull the SD card and reflash it.
The lesson? You better love this stuff... And sometimes, finding a missing Pi Zero is as much detective work as it is networking, almost not worth it.