I was wondering if it's possible with asus rt-ac66u wireless router to create a configuration where the router provides two SSIDs as follows:
The first ("intranet") should be bridged (with no DHCP or NAT) to the LAN ports, i.e operating in AP mode only. There will be no DHCP provided for LAN ports either of course. LAN ports and AP clients will not be routed to the WAN port at all.
The other SSID ("guest") should be routed through the ASUS with the "standard" DHCP/NAT configuration to the WAN port, which will function as it normally does (i.e. will get IP address from cable modem e.g.).
