I have an ASUS RT-AC66u and I am using Tomato by Shibby 140 AIO 64K I've used a different 3rd party firmware previously and have set up a guest network with no problem. However I encountered a bug with it's WPA2 implementation if you have a Wi-Fi printer it will drop and be inaccessible until you reboot either the router or printer and remain for only a couple of hours. Flashed Tomato by Shibby and Printer works fine and is stable, awesome build. Primary network 10.0.0.0/24 Guest network 192.168.0.1/24 WAN is disabled and bridged to LAN. Use user-entered gateway if WAN is disabled is selected I have the IPTables, but this site won't let me post them and keeps giving me a warning that a "sneaky URL has been detected in the content". I can PM them to someone, or if someone can show me how I can post them here I will. No luck, no matter what I do I can't get the guest WiFi to get internet access.