@mbstudio/dns-check

A command-line tool that compares a DNS record across multiple resolvers.

Installation

npm install --global @mbstudio/dns-check

Usage

# The A record type is used by default
dns-check example.com

# Query a different record type
dns-check example.com -t NS
dns-check example.com --type MX

# Check whether a specific value is returned
dns-check example.com --expected 93.184.216.34
dns-check example.com -t NS -e a.iana-servers.net

With -e or --expected, the Status column shows ✓ OK when the expected value is present in the resolver response, or ✗ NO otherwise. Resolution errors remain displayed as ✗ Failed.

By default, the following public resolvers are queried: Google (8.8.8.8), Cloudflare (1.1.1.1), Quad9 (9.9.9.9), OpenDNS (208.67.222.222), AdGuard DNS (94.140.14.14), CleanBrowsing (185.228.168.9), Completel - SAS (83.145.86.7), ServiHosting Networks S.L. (84.236.142.130), Universitaet Leipzig (139.18.25.33), Universidad LatinoAmericana S.C. (200.33.3.123), Swisscom AG (195.186.1.111), and NTT (118.3.227.163).

Some of these resolvers apply protection against malicious domains or content filtering. A different result may therefore be intentional, rather than a DNS propagation issue.

Add a resolver

dns-check add -ip 9.9.9.9 -name Quad9

Added resolvers are saved in your system configuration directory and included in future checks.

dns-check resolvers
dns-check remove Quad9

Development and publishing

npm install
npm run build
npm run release:check

Publish to npm

The package is configured to publish publicly under the @mbstudio scope. After authenticating to the npm account that owns that scope, publish it with:

npm login
npm publish

prepack and prepublishOnly compile the project before packaging and publishing. publishConfig.access ensures that this scoped package is public.