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!

  • grayatroxEnglish
    1•6 months ago

    Your router is the gateway to the internet. I could be wrong here, but this is why your devices can see it. They need to know where they can access the internet.

    • AtemuEnglish
      1•6 months ago

      DHCP is a protocol where the “router” tells the devices that it is the gateway.

      • grayatroxEnglish
        2•6 months ago

        So gateway refers to where to find the DHCP server?

        • AtemuEnglish
          2•6 months ago

          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.

        • @[email protected]English
          2•6 months ago

          Gateway is the path where your devices go if it needs to go out of the network, eg. the Internet, different subnet.

        • @[email protected]English
          1•6 months ago

          No, that’s handled by ARP requests. In this case, it’s likely that the DHCP server is on the gateway, as that’s a pretty common setup for home ISP router arrangements.

          Gateway refers to a router that has access to other networks. In this case, the default gateway, which will be the router that has access to the internet.

          DNS or name servers are a separate option in DHCP leases, as are the IP addresses for DHCP servers, which are more of a windows thing generally.

          In this case this comment is probably an accurate description of what’s happened:

          https://lemm.ee/comment/7429148