- When the GL device’s DHCP server is disabled, then it should work when connected to the LAN port. You’ll need to access the GL device’s admin settings using whatever IP address it receives from the Asus router OR statically configure the GL IP to be something in the Asus router’s range. For example if it uses 192.168.0.1, then make your GL device 192.168.0.20 (assuming .20 is outside of the Asus’s DHCP range)
- If you’re connecting the primary router to the WAN port, then you’ll want to use the advanced settings to reconfigure the WAN port to be part of your LAN instead (though then you’ll still need disable DHCP authoritative mode). Otherwise you end up double NAT’d where your Asus router has one IP range and your GL device is yet another segregated ‘network’ down the tree with its own IP range.
It’s probably simpler to just use the LAN port without the authoritative DHCP server on the GL, unless you happen to want to use both LAN and WAN ports on the device as part of your LAN.