Hello all! I think I'm having a bit of trouble with my home network. It appears that all of my devices are using my Pi-hole DNS because I can see them all listed in the UI. But, when I check the devices, I can see both the Pi-hole IP address and the router's. Pi-hole is listed first, so I'm assuming everything is using that, but I don't want the devices on my network to even know about the router DNS. I've heard of aggressive devices like Roku exploiting things like this.
I have an ASUS RT-AX55, so I believe I have full control of any setting I need. Any advice? Is this not even a problem?
EDIT: The latest firmware for the RT-AX55 is 3.0.0.4.386_52041, and, according to this (https://www.asus.com/support/FAQ/1050080/) I need 3.0.0.4.388.22525 to get the setting I need. @princessnorah@lemmy.blahaj.zone's screenshot shows the settings I need but I only have one DNS field. My suspicion was correct that the router was sending itself as DNS2. It's an imperfect solution, but I changed my upstream DNS on my router to point to the Pi-hole for now. It's a bit frustrating to not see the actual device the traffic is coming from instead of "router" but at least ALL of my traffic is now being routed through the correct DNS server.
At this point, it looks like I cross my fingers and try using Pi-hole DHCP again or get a new router.
EDIT2: I found that the RT-AX55 doesn't have the UI to change DNS2, but the property is there if you use SSH. Just log in and run this: nvram set dhcp_dns2_x=<PIHOLE_IP> | nvram commit. Problem solved!
Thanks for the help, y'all!
Note that what is typically referred to a "router" in a home setting is actually many different devices/services in one. It's usually a combination of router, switch, firewall, DHCP server, DNS server, Wireless Access Point, modem and probably a couple other things I forgot.