Yes — cdn.benu.cz has IPv6.

Has both IPv4 (A) and IPv6 (AAAA) addresses.

B
IPv6 readiness
Works over IPv6, with one gap: www doesn't fully work over IPv6.
Website over IPv6
cdn.benu.cz has 2 IPv6 addresses and answers on every one we tested.
✓ 2606:4700:10::6814:2279 answers · 443✓ 2606:4700:10::ac42:9608 answers · 443
yes
www over IPv6
www.cdn.benu.cz has no AAAA record.		no
Mail servers (MX) have IPv6
No MX records, so mail goes to the domain's own address (implicit MX). It has an AAAA record.		yes
Nameservers have IPv6
2 of 2 nameservers checked have an AAAA record, so IPv6-only resolvers can look the domain up.
hunts.ns.cloudflare.com ✓joyce.ns.cloudflare.com ✓
yes
HTTPS over IPv6 · not part of the grade yet
Loads over IPv6 with a valid certificate: HTTP 403.
https://cdn.benu.cz/ via 2606:4700:10::6814:2279 → 403
works
 Which outside scripts, fonts, payments or chat cdn.benu.cz loads from have no IPv6.
 Load cdn.benu.cz over IPv6 from up to six other places — a second opinion.

What's keeping cdn.benu.cz from an A

  1. Add IPv6 for www.cdn.benu.cz
    www.cdn.benu.cz has no AAAA record. Get www's IPv6 address from whoever hosts www and add it as an AAAA record. If the same server already serves both names (and its certificate covers www), you can reuse cdn.benu.cz's AAAA record(s) for www. How to add an AAAA record

Check again

cdn.benu.cz  Has IPv6

A (IPv4)104.20.34.121
172.66.150.8
AAAA (IPv6)2606:4700:10::6814:2279
2606:4700:10::ac42:9608

www.cdn.benu.cz  No address

A (IPv4)none
AAAA (IPv6)none

Browsers on dual-stack networks will usually pick IPv6 here (the "Happy Eyeballs" algorithm races both and prefers v6).

Copy the evidence — a citation-ready record of this measurement

 Permanent link: aaaa.bot/r/3je9co5tjZ · How we measure

Checked 2026-11-05 21:28:31 UTC. Full DNS report: dns.pizza/domain/cdn.benu.cz · Age, certificate and blocklists: how.is/cdn.benu.cz · JSON: /api/v1/cdn.benu.cz