Use encryption, using vpns for such a trivial task is a “really bad idea”
There are many cases when somebody wants to have their dns public, maybe they want to share with their friends, family, community, audience (not everyone is a solo server user)
Also, it’s good to use your dns even before connecting to the vpn. Just use encryption, it’s safe and nice
Keeping 53 opened is not that bad, the only thing you will notice is an increased load on your server if somebody tried to ddos somebody’s server using your dns
P.S. Or as somebody mentioned below, use rate limiting. It’s described pretty well in some other comments. Not just “spooky internet port”
Use a public dns provider. Cloudflare, route53, dyndns (are they still around?), etc. Cheap, reliable, no worries about joining a ddos by accident. Some services are better left to experts until you really know what you’re doing.
And if you do really know what you’re doing you’ll use a dns provider rather than host your own.
Host your own private DNS - yes, knock yourself out. I highly recommend it.
Public DNS? No - don’t do that.
There are two services homegamers should be extra cautious of and should likely leave alone - DNS and email. These protocols are rife with historic issues that affect everybody, not just the hosting system. A poorly configured DNS server can participate in a DDOS attack without being “hacked” specifically. A poorly configured mail server can be responsible for sending millions of spam emails.
For a homegamer you probably only need a single public DNS record anyway (with multiple CNAME if you want to do host based routing on a load balancer). You take on a lot of risk with almost zero benefit.
From outside? Set up a Cloudflare account and point the NS from your registrar to it.
From inside? Set up unbound on a docker host and don’t open it to the internet. Use that one when you’re local and the normal public DNS when you’re outside. But everything I’m seeing in here makes me sure you shouldn’t even consider opening ports in your firewall to expose inside host services. Use a VPN when you’re roaming, and only use your DNS for local servers/hosts via that VPN. The only use for your outside domain name should be to point a single hostname to your outside IP address so you can use it for your VPN endpoint.
Use DNS challenges for LetsEncrypt cert requests and remove host entries from your Cloudflare after you get your cert.
I use a DNS server on my local network, and then I also use Tailscale.
I have my private DNS server configured in tailscale so whether on or off my local network everything uses my DNS server.
This way I don’t have to change any DNS settings no matter where I am and all my domains work properly.
And my phone always has DNS adblocking even on cell data or public Wi-Fi
The other advantage is you can configure the reverse proxy of some services to only accept connections originating from your tailscale network to effectively make them only privately accessible or behave differently when accessed from specific devices
This is why the concept of running services until different ports than default isn’t a real security measure, it doesn’t actually take any effort to figure out what kind of service is running on a port.
I use technitium but it’s like pihole, designed for a few concurrent users in a local network? Instead you want that anyone in the world can use your DNS?
But you would only attract bad actors, normal users won’t use a random DNS server as it could redirect specific sites to phishing pages
This right here. As a member of the OpenNIC project, I used to run an open resolver and this required a lot of hands-on maintenance. Basically what happens is someone sends a very small packet requesting the lookup of something which returns a huge amount of data (like DNSSEC records). They can make thousands of these requests in a short period, attempting to flood out the target domain’s DNS servers and effectively take them offline, by using your open server as the attacker.
At the very least, you need to have strict rate-limiting controls on DNS lookups. And since the requests come in through UDP, they can spoof their IP address so you can’t simply block an attacker. When I ran into this issue, I wrote up scripts to monitor for a lot of requests to the same domain name and outright block those until the attack stopped. It wasn’t a great solution, but it did at least make sure my system wasn’t contributing to an attack.
Your best bet is to only respond to DNS requests for your own domain(s). If you really want an open resolver, think about limiting it by creating some sort of sign-up method (for instance, ddns servers use a specific URL to register the changing IP of known users), but still keep the rate-limiting in place.
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