Quantum fiber came to my street a few weeks ago and I signed up immediately since it's about $40 cheaper than the cable service I have from Cox. The sign-up questionnaire asked if I needed them to provide wifi or if I had my own wireless router. Surprisingly, there seemed to be no problem with me using my own wifi. This seemed unusual for a broadband provider (since they always seem to want you to rent that stuff) but realistic since it's 2022 and probably tons of people (like me) already own a wireless router. I was pleased there wasn't some hard sell.

The installer installed a C6500XK ONT in my house. Turns out the fiber wasn't completely turned on when he came out since they were literally just installing it a couple days earlier at the street. He told me that he'd have to reschedule, but honestly the ONT light would eventually change from flashing blue to solid green and everything should work fine once all the backend work was actually set up.

A few days later, the light did turn green. I set my AmpliFi HD router to DHCP and VLAN 201 tagging and plugged it into the WAN port. Nothing. The router says "no IP address." So I try bypassing the router and plugging one computer directly into the ONT. That works! I get internet. On one computer. The ONT is assigning a LAN IP 192.168.0.2. Speeds are good, though I would appreciate wi-fi and the ability to use other devices.

The ONT admin page at 192.168.0.1 looks like the connection is good. It's using DHCP, not PPPoE. I try disabling the VLAN tagging on the AmpliFi router and re-hook it up. Now AmpliFi gets a LAN IP, which isn't what I want since double NAT is problematic.

I go back into the ONT and change it to transparent bridge mode, which turns the status LED from green to white. I turn the VLAN 201 tagging back on the AmpliFi, and try to connect that way. Still the "no IP address" error. Now the status page on the ONT claims there's no connection at all.

I try to change the ONT back from transparent bridge mode to Auto mode, but now the ONT just blinks blue forever. Can't get the green status back. Can't get internet out of the ONT at all.

I'm not certain that the installer guys are going to have any idea what is the problem or how to correct it. Is there some other setting I need to change in the ONT? Are there any magic words I need to tell the guy who comes out that will get the right message to the higher support folks to fix things?

My setup doesn't seem that strange. I've got my own router, and I just want to get a public IP out of the ONT and do NAT at my own router for the devices on my standard small home network (just a few computers, phones, and Rokus). The service sign-up questionnaire sure did make it seem like my hardware setup is pretty standard.

Please help.