Hi team

In my home I have a Spark fibre connection using a Fritzbox 7530 which is connected via ethernet to an unmanaged 16-port switch (all gig ports / cables). I also have a Ubiquiti Unifi AC Lite connected to a separate port on the fritzbox. This setup has been working fine for the best part of 10 years, the only new(ish) part is the Fritz 7530 which replace a 7390 about three months ago.

Yesterday I woke up to find that anything connected via the switch was complaining no network, and some devices had gone ahead and self-assigned a 169 IP.

In the Fritz UI many of the devices still showed as connected with a valid IP (btw I am using the Fritz's DHCP here - no static addressing, though some devices are given the same IP by the DHCP server).

I disconnected and reconnected the ethernet cable between the switch and the fritz and rebooted the switch. Lo and behold, everything worked so I figured the cable had somehow unseated itself after 10 years continuous service.

Then, this morning, the same thing happened again. This time I replaced the cable between the switch and the Fritz, and for good measure I connected it to a different port on the Fritz. This initially solved the problem again, but this time only for a couple of hours before I again lost everything connect to the Switch.

The Fritz's self-diagnostics show no issues and there is nothing in the error logs. The switch is unmanaged so nothing to look at there.

So now I'm stuck wondering whether the switch is dying, or if the Fritz is faulty. Any tips / suggestions to isolate the problem?

Cheers!