Ubiquiti USG with FTTP using the Smart Hub 2 (because of Digital Voice)

[iapainter]

Unlike this post that's setting up USG by bypassing the Smart Hub: 

Solved: Using BT Fibre FTTP with UniFi Security Gateway (U... - BT Community

I want to setup Ubiquiti Secure Gateway (USG) with the Smart Hub 2 that came with my FTTP Fibre 9000 (inc Digital Voice). I could connect USG direct to ONT following the above community post for a  PPoE connection but I need Digital Voice and it's my understanding that the Smart Hub needs to stay if you want Digital Voice to work. Given that I have to keep the smart hub I thought the correct way of doing it would be:

ONT Lan -> BT Smart Hub (Wan) -> BT Smart Hub (Lan Port 1) -> Ubiquiti USG (Wan Port 1) -> Ubiquiti USG (Lan Port 1) -> Uniquiti PoE24 Switch

I've adopted the USG into the Ubiquiti Controller and both the Wan and Lan ports on the USG are green. However, there's no internet. 

When I remove the USG and connect as follows everything is fine

ONT Lan -> BT Smart Hub (Wan) -> BT Smart Hub (Lan Port 1) -> Uniquiti Poe24 Switch

It seem that whenever I put the USG in the middle and there's no Internet.

Could it be that I have to switch DHCP off on the Smart Hub? If I do this, wont it stop Digital Voice working? My plan was to put up with the double NAT situation and have DHCP on the Smart Hub and USG

[licquorice]

Turning off DHCP on the hub won't affect Digital Voice, DV is DECT not WiFi.

Try giving the USG an IP address of 192.168.1.10 and gateway 192.168.1.254

[iapainter]

Thanks for the advice that makes a lot of sense. That said, I'm going round in endless circles and not getting to far. Something seems to be resetting the IP of the USG back to 192.168.1.1 after I change it to 192.168.1.10

Here's what I've done so far. I'm using Unifi Controller v6.2.26 and using SSH into the USG to change the IP.  To change the IP I have this setup ONT->Super Hub Wan-> Super Hub Lan -> Unifi Switch Lan -> Unifi Switch Lan -> USG Lan. I'm following this to change the IP on the USG:

How To: Change the Internal IP On Ubiquiti Usg-Pro-4 Using CLI (pei.com)

I change the IP on the USG and that instantly reflects in the Unifi Controller, then a browser refresh later its back to 192.168.1.1. I noticed in the SuperHub setting its set to a static IP on 192.168.1.1 but there's no means to change it. What looks like a button 'Always Use this IP' is locked and also link local address states 'Assigned by Device'. I'm four hours in, on this and it's driving me nuts, the Unifi config is so awkward and counter intuitive.

As I'm not getting anywhere with change the USG IP, is there a scenario where I can connect the USG direct to the ONT and have the SuperHub as a 'dumb' device without any PPoE and DHCP just managing the Digital Voice. So the topology would be:

ONT Lan -> USG WAN -> USG LAN -> Switch LAN -> Switch LAN -> Super Hub (with PPoE and DHCP switched off)

[licquorice]

192.168.1.1 will be ok. Is the gateway set to 192.168.1.254, that's the important bit.

No, you can't make that configuration work. The SH2 needs to be connected to the ONT.

[iapainter]

Yes the Gateway settings were pretty straight forward

[iapainter]

I have noticed that the WAN port never gets an IP address from the Smart Hub. I would have thought that it should have one? 

[licquorice]

It's the wan port that you need to give the 192.168.1.10 or 1 to not the LAN The USG subnet will be a different subnet to the SH2

[iapainter]

Okay so the USG LAN by default gets allocated 192.168.1.1 and I should manually set the USG WAN to 192.168.1.10. I would have thought the SuperHub would have automatically given the WAN port an IP, it only seems to have the LAN port registered

[licquorice]

I have no knowledge of the USG at all, but it will depend on the USG requesting an IP address from the hub. I suspect you will need to configure the wan connection type as DHCP. You have possibly set it to PPPoE as if it were connected to the ONT.

[licquorice]

Thought the USG might have a manual setup option.