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!

  • returned@sh.itjust.worksEnglish
    14·
    11 months ago

    The DHCP server pushes the DNS configuration to the clients. Is your Asus router running the DHCP server? If so, in DHCP configuration, set the DNS to point to your Pi-Hole

    • shiftymccool@lemm.eeOPEnglish
      1·
      11 months ago

      I have my router as DHCP and I also have the DNS set to the pi-hole which I’m assuming is how the devices are getting it. I’m just not sure why it’s getting my router IP as well.

      • kylian0087@lemmy.worldEnglish
        4·
        11 months ago

        Perhaps because the curent lease has not expired yet. Remove the lease in the router or force the client to get a new lease

      • grayatrox@lemmy.worldEnglish
        1·
        11 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.

        • Atemu@lemmy.mlEnglish
          1·
          11 months ago

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

            • Lemmeduit@lemmus.orgEnglish
              2·
              11 months ago

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

            • Atemu@lemmy.mlEnglish
              2·
              11 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.

            • med@sh.itjust.worksEnglish
              1·
              11 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

      • returned@sh.itjust.worksEnglish
        1·
        11 months ago

        Some devices get confused if there is only one DNS server provided by the DHCP… Maybe try setting your PiHole IP for both “Primary” and “Alternative” DNS server

        • shiftymccool@lemm.eeOPEnglish
          1·
          11 months ago

          I only have one dns field. Apparently, there’s a fork of asus software that provides 2 so my suspicion is that the router is automatically supplying its own IP as dns2

  • walden@sub.wetshaving.socialEnglish
    3·
    11 months ago

    Like the other poster said, this will be configured on your routers settings. You can configure more than one DNS address, the 2nd (etc.) being backups if the first one stops working.

    • shiftymccool@lemm.eeOPEnglish
      1·
      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.zoneEnglish
        2·
        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.auEnglish
        1·
        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.eeOPEnglish
          1·
          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

  • BearOfaTime@lemm.eeEnglish
    31·
    11 months ago

    Is DNS enabled on your router? It’s usually (or should be, imo) a separate setting from DHCP.

    Turn off the routers DNS server, then it’ll have no reason to add the IP to the DHCP Config.

    Double check the DHCP Config on the router to ensure it’s only deploying the Pihole address.

  • Decronym@lemmy.decronym.xyzBEnglish
    1·
    11 months ago

    Acronyms, initialisms, abbreviations, contractions, and other phrases which expand to something larger, that I’ve seen in this thread:

    Fewer Letters More Letters
    DNS Domain Name Service/System
    IP Internet Protocol
    PiHole Network-wide ad-blocker (DNS sinkhole)

    3 acronyms in this thread; the most compressed thread commented on today has 7 acronyms.

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