Manage DNS and DoH servers from netwatch

🛈 This script can not be used on its own but requires the base installation. See main README for details.

Description

This script reads server state from netwatch and manages used DNS and DoH (DNS over HTTPS) servers.

Requirements and installation

Just install the script:

$ScriptInstallUpdate netwatch-dns;

Then add a scheduler to run it periodically:

/ system scheduler add interval=1m name=netwatch-dns on-event="/ system script run netwatch-dns;" start-time=startup;

Configuration

The DNS and DoH servers to be checked have to be added to netwatch with specific comment:

/ tool netwatch add comment="doh, hostname=cloudflare-dns" host=1.1.1.1;
/ tool netwatch add comment="dns, hostname=google-dns" host=8.8.8.8;
/ tool netwatch add comment="doh, dns, hostname=quad-nine" host=9.9.9.10;

This will configure cloudflare-dns for DoH (https://1.1.1.1/dnsquery), and google-dns and quad-nine for regular DNS (8.8.8.8,9.9.9.10) if up. If cloudflare-dns is down the script will fall back to quad-nine for DoH.

Giving a specific query url for DoH is possible:

/ tool netwatch add comment="doh, hostname=nextdns, doh-url=https://dns.nextdns.io/dns-query" host=199.247.16.158;

Note that using a name in DoH url may introduce a chicken-and-egg issue!

Sometimes using just one specific (possibly internal) DNS server may be desired, with fallback in case it fails. This is possible as well:

/ tool netwatch add comment="dns, hostname=pi-hole" host=10.0.0.10;
/ tool netwatch add comment="dns-fallback, hostname=cloudflare-dns" host=1.1.1.1;

Tips & Tricks

Use in combination with notifications

Netwatch entries can be created to work with both - this script and netwatch-notify. Just give options for both:

/ tool netwatch add comment="doh, notify, hostname=cloudflare-dns" host=1.1.1.1;