I once bought a router to use for my internet when I moved into my new house just to find out that it “wasn’t compatible” with Verizon’s service. I still have it (because I’m terrible about returning things). Is there any point in keeping it? Is there anything fun or interesting that I could do with it?
The easiest way would be to just bridge the ISP router if it supports that feature. To connect back to the ISP router’s webui you can setup outbound NAT on your second router (generally only available on enterprise gear). Don’t double NAT unless there’s no other option.
If you can bridge, the sky’s the limit in terms of what gear you can have on the backend. My bridged modem is directly connected to a L3 switch which links to my Proxmox cluster, and my Opnsense router exists virtually in the cluster and can be migrated freely between the machines.
Your setup sounds very interesting to me. If I wasn’t so obsessed with writing code, I would have been deep into hardware. I imagine that it will become a hobby of mine when I hit my midlife crisis. I’ll be buying up all kinds of hardware, quiting my job, and connecting everything to everything.
Homelabbing is an amazing hobby if you’re into this stuff, and you can go as far down the rabbit hole as you like :)
My lab also supports my coding endeavors since I can deploy VMs, run a local Git server, and so forth. Most of my development is done in a SPICE VDI on Proxmox.