And that makes 3

This site was briefly offline today (about 30mins) due to the fact that I had to replace our Fritzbox modem for the 3rd time. This time however I managed to find the causality leading to the event.

We are expecting our first kid at the end of September. In preparation to this event, I'm making the house kid-safe. This includes replacing all the wall power outlets (the new ones have a kind of shutter preventing a kid from inserting a tool). To do this I have to switch off the main power. When I do that, the server, network and modem continue on UPS provider power.

About 2.5 weeks ago, I was replacing a wall outlet, when I noticed that the modem lost the Internet connection. After main power came back on, the modem reconnected, but that night the modem lost connection again. When I manual rebooted the modem, it went into a reboot cycle. I only managed to get it online after plugging it directly into a wall outlet instead of the UPS. It then rebooted for about 5 times and connected. I then disconnected the phone wire and reconnected and sure enough the modem started rebooting again. This time it came online after 10 reboots.

I called my provider immediately reporting the malfunction (I had to wait for 1.5 hours on the phone; so much for that famous xs4all service; then they forgot to post the modem, so I had to call again. At the moment I'm really regretting the switch to this provider) and a new modem was sent (eventually). In the meantime I stopped replacing the wall outlets in fear of not being able to get back online.

I received the new modem today. This time I connected it directly to a wall outlet and the phone cable directly to the phone connection, instead of the surge protector on the UPS. This required some rearranging as the surge protector is now on the network cable coming from the modem. Instead of one big safe-zone I now have 2 different zones. I took care not to have network and power cable from the unsafe zone and safe zone in one duct. While I was offline, I also too the opportunity to replace the remaining wall outlets. So instead of the 5 minutes needed to replace the modem, we were offline a little bit longer. But luckily, I'm all set now.

As to the reason why the modems broke... I can only guess. Probably some phase mismatch between the switched power supply of the modem and the inverter of the UPS. I find unlikely that it is caused by noise coming from one of the other pieces of equipment connected to the UPS, since each socket has its own filter. But then again, I'm not an electronics expert.