Configure Eir F2000 modem with Unifi USG

So I don't forget (again) ....

Having implemented a Unifi network infrastructure that's solved my home WiFI problems and introduced a degree of structure and security to my network, I wanted to document how I'd configured my service provider all-in-one modem/router to act as just a modem in front o the Unifi USG that handles or hands off everything else.

The first thing to note is that, once this is set up, it won't be possible to access the ISP modem interface from inside the network. (well, actually, it might be possible, but I was too lazy to figure out the required routing rules and configuration, so I just connect up as outlined below).

My setup sees the incoming DSL line connected to the F2000 as usual. My EirTV IPTV box is directly connected to one of the F2000 LAN ports. Another patch cable runs from another F2000 LAN port to the WAN port on the USG.

When I need to configure the F2000, I connect a laptop directly to a third LAN port. It shows up in the network of Windows 10 as follows (other OS may vary);

I can then log in to the F2000 admin portal. Here's the home page;

All WiFI is switched off in the F2000 as UniFi looks after that. The main configuration to make the F2000 play nice is setting the active connection (Internet -> Internet Settings) to 'Bridged' and configuring the VLAN for that connection as shown;

Here are some of the remaining admin pages that have some configuration. Any not listed have all settings off or at default;

On the Unifi side, there's no special configuration in the USG admin interface;

And in Unifi Settings -> Network -> WAN;

I'm unsure whey 'Use VLAN ID' is unchecked here, but this is the working configuration, so it must not be needed.