Windows 10 VPN not able to connect through RBR20, can connect via mobile hotspot

[wifitech]

Connecting to a Ubiquiti Unifi USG VPN using the Windows 10 built-in VPN client works perfectly fine via mobile hotspot, and used to work on this network, but now it cannot connect via the Orbi. I can connect to the hotspot and connect all day long, but through the Orbi it does not work. I have factory reset the Orbi and still no joy. Any ideas?

[CrimpOn]

You may be assuming people know more than they do.  Can you please describe two things (a) where is the Ubiquiti (device?) located in relation to the Orbi (between the Orbi and the modem? behind the Orbi? some other location?) and (b) what is the goal?  (to connect to devices inside the Orbi network from outside? or, to connect from inside the Orbi to devices in another location?

[wifitech]

Thanks for the reply. Two different networks. Network A includes a windows 10 computer which connects via the RBR20 to a cable modem. Running Windows 10's VPN client, that computer connects to network B's ubiquiti usg VPN across the internet.

The goal is to connect one device behind the Orbi to an external network via VPN. This works fine via other connections. I can connect the computer to my cell phone's hotspot and it will connect to the VPN instantly. Same goes for other sites using the same ISP but no Orbi. And in fact it has worked behind the Orbi before although intermittently. The Orbi seems to be the problem.

[CrimpOn]

Could you do me a favor and check that no services are blocked?

On the Orbi web interface, the Advanced Tab->Security->Block Services.

I believe the default is not to block any services, but I notice that several types of VPN are the drop down list.

Can you confirm exactly which type of VPN the Ubiquiti uses?  In a brief search, I turned up references to UDP ports 500 & 4500 and TCP port 1701 (L2TP)?  My thought is that Orbi allows outbound connections, but not inbound connections.  For that, specific ports have to be forwarded to your Windows 10 machine.  (And, I have no idea if this is the problem, or if it is which ports need to be forwarded.)

There is a fascinating thread about Windows 10 VPN here: https://community.ui.com/questions/VPN-USG-Pro-4-Windows-10-Client-Not-Connecting/c8ec2d1f-7c99-49b4...