This is my current setup: Asus RT-N16 running TomatoUSB (main router) - main WiFi (192.168.1.0/24) Buffalo WHR-HP-G54 running DD-WRT (connected to the main router via wire) - extends main WiFi - guest WiFi on separate subnet (192.168.2.0/24) The Buffalo router is not handling DHCP for the main wifi, but has some commands to handle DHCP for the guest wifi only (see my setup here) I currently have QoS set up on Tomato router (perfected after many months of fiddling), but I would like to limit traffic to the guest wifi (configured on the dd-wrt router). I tried adding a rule to the Tomato QoS for Source IP "192.168.2.0/24" and set it to Lowest, but it doesn't seem to see this traffic. I believe the subnet separation only occurs within DD-WRT and once the traffic is routed through the Tomato router, it all looks the same to Tomato, but I'm not sure if this is the case. I tried setting up QoS on DD-WRT, but I don't think it will not work as the DD-WRT router is handling wireless traffic ONLY and will not take into account all other traffic on my network. Since the Tomato router sees all traffic within my network, including both wireless networks, I would assume that is the best place to limit the guest wifi traffic, but I don't know how to specify the guest wifi traffic only. Any suggestions??