I'm back to embarrass myself once again by announcing that my C5 appears to be unreachable. The hub LED is green, but it's totally unresponsive.
I awoke this AM to find automations working properly, but the hub was unreachable via Google, the Android app or the http interface.
The hub is entirely unresponsive, including on port 8081. When I disconnect- and reconnect the RJ-45, I can see the light go out and back on again on my switch, which means the C5 is physically connected, but my router has it greyed-out. Hubitat's cloud servers say that it last checked-in right around 2:20AM, just after the switch to Standard Time from DST.
I just left it unplugged for ten minutes and powered it up again. Automations still work properly, so something's running. When I try to connect to it at its assigned IP address, the connection times out. When I try to find it conventionally via the Android app, it times out. But when I do an advanced search, via its MAC address, not only is the hub found, but its IP address is correct as reserved.
But when I hit "Connect to hub," it times out. Any ideas?
What type of home network equipment so you have? It might be worth trying a reboot of all network gear to see if that resolves the problem? Maybe try a new Ethernet Patch Cable? A different network port on the switch/router?
Can you PING the IP address from another computer on the same network?
The first thing I did was reboot the router (Synology RT2600ac), the D-Link switch to which it's attached and my cable modem. Plugging the Ethernet cable directly into a known working port on the router, bypassing the switch, doesn't help.
Ping reports that 10.10.10.200 is unreachable.
I just unplugged the Ethernet cable and ran advanced discovery again. It still "found" the hub, so I expect the data is cached somewhere and the fact that find-by-MAC works is a red herring.
I left the hub unplugged for a half hour, powered it back up, and now I find it is reachable again, but for some reason my dashboards won't load. That's not such a big deal, so I'll work on that myself for a while.
It sounds like a corrupt database. Go to your hubip:8081, download latest backup to your pc, then do a soft reset and upload your backup from the pc. Then that said, if this happens again, try switching browsers as well as clearing your cache. I've seen the same thing happen when the browser was trying to use secure https instead of http
Since the problem disappeared on its own, I've come to the conclusion that it was an Ethernet problem after all. Remember, I couldn't reach the IP, no matter what port, including via ping. Now, I wish I'd done more debugging.