By router I mean consumer grade that combines router/switch/wireless ap etc. I have a primary router that from the ISP. I want to connect a second router to it via Ethernet cable. The second is to provide the wi-fi (the first would have wi-fi disabled) but I want both to keep Ethernet ports enabled. I know it's strange but this is what I want.
I tried to set it up but ran into trouble. What's the best approach, dmz, port-forwarding or bridging? I had issues with one device not being able to access DNS. Also I find it confusing whether to plug Ethernet into WAN or LAN port on the second router?