You can run a DNS server (2025)(simonsafar.com)

75 points by surprisetalk 5 days ago | 38 comments

  • gerdesj 3 days ago
    I've run DNS servers in the past - BIND and pdns. I've now gone all in ... because ... well it started with ACME.

    As the OP states you can get a registrar to host a domain for you and then you create a subdomain anywhere you fancy and that includes at home. Do get the glue records right and do use dig to work out what is happening.

    Now with a domain under your own control, you can use CNAME records in other zones to point at your zones and if you have dynamic DNS support on your zones (RFC 2136) then you can now support ACME ie Lets Encrypt and Zerossl and co.

    Sadly certbot doesn't do (or it didn't) CNAME redirects for ACME. However, acme.sh and simple-acme do and both are absolutely rock solid. Both of those projects are used by a lot of people and well trod.

    acme.sh is ideal for unix gear and if you follow this blokes method of installation: https://pieterbakker.com/acme-sh-installation-guide-2025/ usefully centralised.

    simple-acme is for Windows. It has loads of add on scripts to deal with scenarios. Those scripts seem to be deprecated but work rather well. Quite a lot of magic here that an old school Linux sysadmin is glad of.

    PowerDNS auth server supports dynamic DNS and you can filter access by IP and TSIG-KEY, per zone and/or globally.

    Join the dots.

    [EDIT: Speling, conjunction switch]

    [-]
    • rdevilla 51 minutes ago
      > Sadly certbot doesn't do (or it didn't) CNAME redirects for ACME.

      Are you certain? Not at a real machine at the moment so hard for me to dig into the details but CNAMEing the challenge response to another domain is absolutely supported via DNS-01 [0] and certbot is Let's Encrypt's recommended ACME client: [1]

          Since Let’s Encrypt follows the DNS standards when
    looking up TXT records for DNS-01 validation, you can
    use CNAME records or NS records to delegate answering
    the challenge to other DNS zones. This can be used to
    delegate the _acme-challenge subdomain to a validation
    specific server or zone.
      ... which is a very common pattern I've seen hundreds (thousands?) of times.

      The issue you may have run into is that CNAME records are NOT allowed at the zone apex, for RFC 1033 states:

         The CNAME record is used for nicknames. [...] There must not be any other
   RRs associated with a nickname of the same class.
      ... of course making it impossible to enter NS, SOA, etc. records for the zone root when a CNAME exists there.

      P.S. doing literally fucking anything on mobile is like pulling teeth encased in concrete. Since this is how the vast majority of the world interfaces with computing I am totally unsurprised that people are claiming 10x speedups with LLMs.

      [0] https://letsencrypt.org/docs/challenge-types/

      [1] https://letsencrypt.org/docs/client-options/

    • adiabatichottub 5 hours ago
      I'm a fan of uACME:

      https://github.com/ndilieto/uacme

      Tiny, simple, reliable. What more can you ask?

      [-]
      • dwedge 1 hour ago
        > don't expect it to automatically set up your webserver to use the certificates it obtains.

        This makes me so happy. Acme and certbot trying to do this is annoying, Caddy trying to get certs by default is annoying. I ended up on a mix of dehydrated and Apache mod_md but I think I like the look of uACME because dehydrated just feels clunky

      • DaSHacka 5 hours ago
        Neat, I've used lego (https://github.com/go-acme/lego) but will certainly have to give uacme a look, love me a simple ACME client.

        acme.sh was too garish for my liking, even as a guy that likes his fair share of shell scripts. And obviously certbot is a non-starter because of snap.

        [-]
        • adiabatichottub 5 hours ago
          Certbot has earned my ire on just about every occasion I've had to interact with it. It is a terrible program and I can't wait to finish replacing it everywhere.

          The new setup is using uAcme and nsupdate to do DNS-01 challenges. No more fiddling with any issues in the web server config for a particular virtual host, like some errant rewrite rule that prevents access to .well-known/.

    • ozim 3 hours ago
      I think CNAME redirections being not supported is reasonable choice. Would make my life easier as well but it opens all kinds of bad possibilities that bad actors would definitely use.
      [-]
      • dwedge 1 hour ago
        Can you give me an example where this is a problem? If someone can create a CNAME they can create a TXT (ignoring the possibility of an API being restricted to just one).

        Without CNAME redirect I wouldn't be able to automatically renew wildcard ssl for client domains with dns that has no API. Even if they do have an API, doing it this way stops me from needing to deal with two different APIs

    • 9dev 3 days ago
      Seconded. Don’t use certbot; it’s an awful piece of user-hostile software, starting from snap being the only supported installation channel. Everything it does wrong, acme.sh does right.
      [-]
      • tryauuum 4 hours ago
        just installed yesterday the certbot on ubuntu 24.04, from the default repos, without any snaps
        [-]
        • mediumsmart 4 hours ago
          same on debian trixie. certbot works fine for me. Zone records in bind, generate the dnskey, cronjob to re-sign it daily and your off to the races. no problems no snaps.
      • locknitpicker 3 hours ago
        > starting from snap being the only supported installation channel.

        This sounds like you are complaining about Ubuntu, not the software you wish to install in Ubuntu.

  • BatteryMountain 1 hour ago
    Get a mini-pc with 2x LAN ports + a mediatek Wifi 6/7 module. Install Proxmox. Make 3 VM's: OpenWrt (or router firmware of choice), unbound and adguard home. Plug your fibre into lan port, plug rest of network into other lan port. In proxmox, set pcie passthrough for one of the Lan ports and the wifi card. Setup openwrt to connect to your isp and points its dns to you adguard home server. Point your adguard home server to your unbound server as upstream. This is a good starting point if you want to get a feel for running your own router + dns. You don't need to use off the shelf garbage routers; x86/x64 routers are the best. On openwrt I configure a special traffic queue so that I don't have buffer overflows, so my connection is super stable and low latency. Combined with the adguard + unbound dns setup, my internet connection is amazingly fast compared to traditional routers.

    Better yet, set up ssh to the proxmox server and ask claude code to set it up for you, works like a charm! claude can call ssh and dig and verify that your dns chains work, it can test your firewall and ports (basically running pen tests against yourself..), it can sort out almost any issue (I had intel wifi card and had firmware locks on broadcasting in 5GHZ spectrum in AP Mode - mediatek doesn't - claude helped try to override firmware in kernel but intel firmware won't budge). It can setup automatic nightly updates that are safe, it can help you setup recovery/backup plans (which runs before updates), it can automate certain proxmox tasks (periodic snapshotting of vm's) and best of all, it can document the entire infrastructure comprehensively each time I make changes to it.

    [-]
    • ssl-3 49 minutes ago
      That seems like a lot of steps that could be reduced to:

        1.  Run OpenWRT
  2.  Use it for the DNS of one's own choosing
  • tzury 56 minutes ago
    Just remember, if you run your own DNS, and you do so for a mission critical platform, the platform is exposed to a udp DDoS that will be hard to detect let alone prevent.

    Unless of course you will invest 5-6 figures worth of US dollars worth of equipment, which by then you can look back and ask yourself, was I better off with Google Cloud DNS, AWS Route 53 and the likes.

  • dwedge 2 hours ago
    I've been tempted by this because I self host everything else, but "adding an entry to postgres instead of using namecheap gui" is overkill, just use a DNS with an API.

    Last few days I've been migrating everything to luadns format, stored in github and then I have github actions triggering a script to convert it to octodns and apply it.

    I could have just used either, but I like the luadns format but didn't want to be stuck using them as a provider

  • defanor 4 hours ago
    I prefer and use the knot DNS server for authoritative DNS (and either knot-resolver or Unbound for caching DNS servers) myself: it is quite feature-rich, including DNSSEC, RFC 2136 support, an easy master-slave setup. Apparently it does support database-based configuration and zone definitions, too, but I find file-based storage to be simpler.
    [-]
    • adiabatichottub 3 hours ago
      The database for configuration and zone data is strictly internal and not tied to an external relational database, like what's shown in the article.
  • WaitWaitWha 3 hours ago
    Running DNSMasq on an old RasPI & USB SSD. No problems no issues. Just quietly runs in the background.
    [-]
    • henrebotha 2 hours ago
      dnsmasq on an RPi Zero 2W is the backbone of my self-hosted setup. Combined with Tailscale, it gives me access from anywhere to arbitrary domains I define myself, with full HTTPS thanks to Caddy.
      [-]
      • ssl-3 15 minutes ago
        At home, I put all of my network infrastructure software in one basket because that seems like the right path towards maximizing availability[1]: It provides one point of potential hardware failure instead of many.

        For me, that means doing routing, DNS, VPN, and associated stuff with one box running OpenWRT. It works. It's ridiculously stable. And rather than having a number of things that could break the network when they die, I only have 1 thing that can do so.

        That box currently happens to be a Raspberry Pi 4 that uses VLANs as Ethernet port expanders, but it is also stable AF with a [shock! horror!] USB NIC. I picked that direction years ago mostly because I have a strong affinity towards avoiding critical moving parts (like cooling fans) in infrastructure.

        But those details don't matter. Any single box running OpenWRT, OPNsense, pfSense, Debian, FreeBSD, or whatever, can behave more-or-less similarly.

        [1]: Yeah, so about that. If the real-world MTBF for a system that relies upon 1 box is 10 years, then the MTBF for a system relying on 2 boxes to both keep working is only 5 years. Less is more.

  • emithq 5 hours ago
    One thing worth noting if you're using your own DNS for Let's Encrypt DNS-01 challenges: make sure your authoritative server supports the RFC 2136 dynamic update protocol, or you'll end up writing custom API shims for every ACME client. PowerDNS has solid RFC 2136 support out of the box and pairs well with Certbot's --preferred-challenges dns-01 flag. BIND works too but the ACL configuration for allowing dynamic updates from specific IPs is fiddly to get right the first time.
  • rmoriz 1 hour ago
    Still running DNS without a database and immutable. Push-based deployment.
  • micw 3 hours ago
    I'd like to run my personal DNS server for privacy reasons on a cheap VPS. But how can I make it available to me only? There's no auth on DNS, right?
    [-]
    • albertgoeswoof 2 hours ago
      It can’t be fully secure but you can use a domain or path with a uuid or similar such that no one could guess your dns endpoint, over dot or doh. In theory someone might log your dns query then replay it against your dns server though.

      You could also add whitelisting on your dns server to known IPs, or at least ranges to limit exposure, add rate limiting / detection of patterns you wouldn’t exhibit etc.

      You could rotate your dns endpoint address every x minutes on some known algorithm implemented client and server side.

      But in the end it’s mostly security through obscurity, unless you go via your own tailnet or similar

    • khoirul 3 hours ago
      You could run it within a Tailscale VPN network. In fact Headscale (Tailscale server) has a very basic DNS server built-in.
      [-]
      • Xylakant 2 hours ago
        That assumes a device that can enter a VPN. I’d like to run a DNS server for a group of kids playing Minecraft on a switch. Since they’re not in the same (W)LAN, I can’t do it on the local network level. And the switch doesn’t have a VPN client.
        [-]
        • ssl-3 1 hour ago
          Perhaps it seems obvious to some, but it's not obvious to me so I need to ask: What's the advantage of a selectively-available DNS for kids playing Minecraft with Nintendo Switch instead of regular DNS [whether self-hosted or not]?

          All I can think of is that it adds obscurity, in that it makes the address of the Minecraft server more difficult to discover or guess (and thus keeps everything a bit more private/griefing-resistant while still letting kids play the game together).

          And AXFR zone transfers are one way that DNS addresses leak. (AXFR is a feature, not a bug.)

          As a potential solution:

          You can set up DNS that resolves the magic hardcoded Minecraft server name (whatever that is) to the address of your choosing, and that has AXFR disabled. In this way, nobody will be able to discover the game server's address unless they ask that particular DNS server for the address of that particular name.

          It's not airtight (obscurity never is), but it's probably fine. It increases the size of the haystack.

          (Or... Lacking VPN, you can whitelist only the networks that the kids use to play from. But in my experience with whitelisting, the juice isn't worth the squeeze in a world of uncontrollably-dynamic IP addresses. All someone wants to do is play the game/access the server/whatever Right Now, but the WAN address has changed so that doesn't work until they get someone's attention and wait for them to make time to update the whitelist. By the time this happens, Right Now is in the past. Whitelisting generally seems antithetical towards getting things done in a casual fashion.)

        • albertgoeswoof 2 hours ago
          Why do you want to do this? What would you redirect / override on this?
    • Loeffelmaenn 3 hours ago
      I just use a VPN like tailscale or wireguard. You can normally also tell clients what DNS to use when on the VPN
    • slow_typist 3 hours ago
      SSH tunnels is a possibility.
  • kev009 2 hours ago
    unbound and nsd for me, always run my own recursor and authority.
  • deepsun 5 hours ago
    How to make it DNSSEC?
    [-]
    • gucci-on-fleek 5 hours ago
      With Knot, you can just add ~8 lines to your config [0], copy the records to your registrar, and then you're done.

      [0]: https://www.knot-dns.cz/docs/3.5/singlehtml/index.html#autom...

      [-]
      • adiabatichottub 4 hours ago
        Knot does make it quite easy. Also, their devs are very responsive to support questions on their mailing list. It is currently my favored DNS.
    • adiabatichottub 5 hours ago
      If you don't absolutely have to, then don't.

      That is to say, if you misconfigure it, or try to turn it off, you will have an invalid domain until the TTL runs out, and it's really just not worth the headache unless you have a real use case.

      [-]
      • deepsun 4 hours ago
        I consider it as basic security measure as SSL. Otherwise any MitM can easily redirect users to a phishing resource.

        Did DNSSEC for company website, worked with zero maintenance for several years. On a cloud-provided DNS. Would want the same on self-hosted DNS too.

        [-]
        • 0x073 3 hours ago
          "Otherwise any MitM can easily redirect users to a phishing resource."

          Yes, but with nowadays https/tls usage it's almost irrelevant for normal websites.

          If bad actors can create valid tls certs they can solve the dnssec problem.

  • Pythius 1 hour ago
    [dead]