Things are a little different this morning, though I am still unable to connect and configure my C-8. I can connect to the internet with the C-8 connected to my switch. However, the Hubitat hub search is either unable to see the C-8, or it comes up with the wrong IP address for the C-8 during the search.
Using the go.hubitat.com configuration webpage, the hub has never been discovered on the basic discovery page, I have always needed to use the advanced discovery page.
A little more information about my home network: My Orbi router is configured to use a less common - but totally legit - reserved private LAN range: 172.16.0.0 thru 172.16.255.255. I can't use the typical 192.168.x.x home network addresses due to weird conflicts with my ISP modem.
I have a Verizon 5G Home Internet gateway for my ISP. The 5G gateway is configured to have all of its router-related functionality disabled (DHCP is disabled, all WiFi radios are disabled, etc.) The connection between the Orbi and the 5G gateway is a stateless autoconfigured IPv6 P2P connection on both ends, with IPv4 disabled on my Orbi, The gateway-Orbi P2P connection is set up as a passthru DMZ connection.
My goal was to make the 5G gateway as invisible to my Orbi and LAN as possible, and letting my Orbi be as unobstructed from the internet as possible (acting similar to an old cable modem). About the only functionality I have enabled on the VZW 5G gateway is its DDNS service, since my gateway switches IP addresses very frequently, sometimes multiple times in a day.
@jameslslate - The hub is getting all its network configuration from my Orbi router, the hub is not being configured manually at all.
@rlithgow1 - I have provided more information about my LAN configuration above, maybe it will help.
@thebearmay - I have about 25 devices on my LAN. Most are configured for the main LAN, some are auto-configured for the guest LAN (which the Orbi DHCP assigns in the 10.0.1.xxx range). The C-8 Hub is connected to the main LAN, and has been assigned an address of 172.16.1.17 by my Orbi.
@jschlote - I have tried http and https, no luck with either.