- If your problem is brief brownouts or similar
my experience is that some consumer broadband routers have cheap power supplies that leaves them in bad states when PCs will pull through
you could put them on a UPS.
-
If your problem is that your router is unstable, you could just replace your router. Like, if you need remote access and you have a flaky router, that seems like a prime choice.
-
You could have a power control device or something and have another machine on your network set up so that if it loses Internet connectivity for some sustained period of time, it power-cycles the router.
-
If this is for when you're a long ways away, do you have a friend who you'd trust with a key and flipping a switch?
-
I expect that there are business-oriented routers that will have integrated watchdog features that will auto-reboot if they hang. I have not gone looking, though.
-
Possibly, if it's compatible with your use case, and uptime is critical enough here, having a second, backup server elsewhere, possibly not self-hosted. I mean, your connectivity is always going to be bounded by the reliability of your residential Internet connection otherwise.