Our home is on an island about 3 miles offshore. We use a wireless point-to-point link for Internet access.
Our ISP supplied all-in-one cable modem/router resides in an electrical box on the shore. There are no users here, and the only device plugged into the modem/router is the wireless bridge. The modem/router is in the default 'routed with nat' setting with DHCP enabled for the LAN. If required, I have the option to set it to 'routed without nat' or 'bridged', and can disable DHCP.
The ISP supplied all-in-one box gets it's WAN IP dynamically. The internal LAN IP is set to 172.16.0.1 and DHCP is enabled for the LAN starting at 172.16.0.10.
The bridges have static IP's of 172.16.0.2 and 172.16.0.3 with a gateway of 172.16.0.1.
3 miles away is the other wireless bridge that is connected to a switch. Also connected to the switch is a wifi access point (for wifi only devices) and various ethernet devices (NAS, printer, etc.).
The problem I have is that when the PTP link goes down (for various reasons) I also lose the DHCP server, meaning the LAN goes down.
I have a spare router at home (TP-Link Archer C7) that I can use to replace the switch and access point if need be, but I'm not sure how to configure it in conjunction with the shore-side router.
Do I leave the shore-side router set to 'routed with nat' but disable DHCP? How do I setup the home-side router? It would be great if I could still access the bridges from the LAN at home (if possible).
Any help offered would be greatly appreciated.