I have a Netgate SGS-8860 with a typical LAN on 192.168.1.x
I also have three of the Google WiFi devices.
Google Wifi has one main device that uses an IP address on the LAN, 192.168.1.195 in my case, and then assigns the other Google WiFi devices and any devices connected to the wireless network with a 192.168.86.x address - the 192.168.86 cannot be changed - it's forced by Google.
The issue is any devices on the wireless network can't see devices on the LAN and vice versa. I'd like to route all traffic between them. How would that need to be done?