Network Tools

Need to figure out your IPv4 when you're dual-stacked with IPv6? Curious which one your stack prefers?
Want to see how your client handles weird TLS? Or HTTP/3?

IP

Find your public IPv4, IPv6 or check what your network stack prefers.

HTTP

Test which HTTP versions your client supports. http.søb.org negotiates the best available version, while the versioned subdomains let you force a specific protocol - useful when debugging proxies, load balancers, or client behaviour.

TLS

Check which TLS versions your client supports. tls.søb.org accepts both TLS 1.2 and 1.3, while the versioned endpoints are strict. Also available: a short-lived certificate issued via the ACME shortlived-profile, and an endpoint serving a valid certificate without a hostname.

Misc

  • info.søb.org - A collection of everything (IP, HTTP and TLS)
  • slow.søb.org - loads forever; handy for testing timeout behaviour (new!)
  • $ dig +short dns-info-experimential.xn--sb-lka.org TXT   (new!) - find your (upstream) DNS resolvers IP and ASN

Publications

Stuff that doesn't fit in a blog post.

Password Policies & Recommendations (2024)

When someone tells you to rotate passwords on a regular basic, tell them 🖕 and link this page.

ACME-CAA setup for Caddy

A walkthrough of configuring CAA DNS records with ACME account binding, for Caddy webserver. Useful if you want to restrict which ACME accounts are permitted to issue certificates for your domain, protects against dangling DNS records, etc.