https://en.wikipedia.org/wiki/AirPort_E ... ison_chart
Not for the faint of heart, but explains why Guest Networking isn't working.Apple did something only Apple does. They made the requirement that the main router that connects your home to the Internet also be an Airport Extreme, otherwise the Guest Network simply does not work.
https://www.thegeekpub.com/5191/use-air ... idge-mode/ENABLE VLAN 1003 ON YOUR SWITCH
If you’re Airport Extreme is not connected directly to your router, you’ll need to enable VLAN tagging on the the ports of your switch in order for it to pass the VLAN 1003 802.1q tags to your router.
CONFIGURE YOUR ROUTER TO IMITATE THE AIRPORT EXTREME GUEST NETWORK
At this point traffic should be passing all the way to your router, but your router doesn’t know what to do with it, and since there is no DHCP server on this VLAN, connected devices cannot get an IP address.
This is going to be very specific to your type of router, and not all routers support VLANs.