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. @[email protected]’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!

  • shiftymccool@lemm.eeOP
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    11 months ago

    The router is running DHCP and is set to hand out the Pi-hole IP as DNS. Interestingly, there’s only one field for this so maybe the router is choosing itself as DNS2? If I go into WAN settings, there are fields for DNS1 & 2 but if I was under the impression that these should be set for upstream DNS.

    • Norah - She/They@lemmy.blahaj.zone
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      11 months ago

      I’m running the Merlin fork of the Asus firmware, so maybe that adds this option, but in my DHCP settings there’s a switch called:

      Advertise router’s IP in addition to user-specified DNS

      Sidenote: The Merlin version of the firmware is great! It lets you run the Diversion adblocker, which functions in the same way as Pihole. However, the RT-AX55U isn’t supported. The AX58U is though, maybe it might be worth upgrading? It’s a lot simpler than running a Pihole separately.

    • dan@upvote.au
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      11 months ago

      If you can’t figure it out, you can always use your PiHole as a DHCP server and disable your router’s DHCP server.

      If I go into WAN settings, there are fields for DNS1 & 2 but if I was under the impression that these should be set for upstream DNS.

      Try set those to your PiHole IP. Then, even if a DNS request goes to your router, it should send the request to PiHole rather than the ISP’s DNS servers.

      By the way, I’d recommend running two PiHole instances so that the internet doesn’t break if you have to take one of them down. There’s a system for AdGuard Home that lets you keep the config for multiple instances in sync - maybe there’s something like that for PiHole too.

      • shiftymccool@lemm.eeOP
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        11 months ago

        Last time I tried that was… problematic. I suppose I could try again…

        I’m kinda just getting started. The goal is to have a media server in addition to my current raspberry pi server that will act as a second dns. If I can’t find a way to keep them synced, I’ll give adguard a try