aos / udns

A simple DNS server

udns

A barebones, simple DNS server implementation for edification and use with my Wireguard VPN.

I've written a blog post about the implementation of this DNS server.

Requirements

• go (tested on 1.14, but could/should work on older versions)

Installation & Usage

1. Clone repository
2. Build with go build
3. Run with:

./udns [-port 8053] [-zonefile file.zone] [-address "127.0.0.1"] [-forward-server "1.1.1.1:53"]

• Port defaults to 8053
• Zonefile defaults to master.zone (you can use http://zonefile.org to create a zonefile)
• Address defaults to empty
• Forward server defaults to 1.1.1.1:53

There is also a bundled systemd unit file that can be modified and copied into /etc/systemd/system/ for an auto-starting service.

A note about Linux distributions with systemd

If you are using systemd-resolved, keep in mind that you will not be able to run this with an empty address on port 53. This is because systemd-resolved creates a local DNS server/cache/resolver that listens on 127.0.0.53:53 and an empty address attempts to listen on all availabe IP addresses of the local system. To get around this, you can specify an -address for others to listen on, a simple one being 127.0.0.1.