ns1.vodafone.cz publishes IPv6 but doesn't answer on it.

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

F
IPv6 readiness
Publishes IPv6 but doesn't answer on it — worse than having none.
Website over IPv6
ns1.vodafone.cz has an AAAA record, but nothing answered on ports 443 or 80. IPv6 visitors wait for a timeout before falling back to IPv4.
✗ 2a00:11b0:5:1::80 no answer
broken
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.
ns1.vodafone.cz ✓ns2.vodafone.cz ✓
yes
 Which outside scripts, fonts, payments or chat ns1.vodafone.cz loads from have no IPv6.
 Load ns1.vodafone.cz over IPv6 from up to six other places — a second opinion.

What's keeping ns1.vodafone.cz from an A

  1. Fix or remove the AAAA record for ns1.vodafone.cz
    Something published an IPv6 address but nothing answers on it, so IPv6 visitors wait for a timeout first. Either make the server listen on IPv6 (and allow ports 443/80 through its firewall), or delete the AAAA record until it does.

Check again

ns1.vodafone.cz  Has IPv6

A (IPv4)217.77.165.80
AAAA (IPv6)2a00:11b0:5:1::80

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/LjKL3elTgG · How we measure

Checked 2026-11-15 19:06:59 UTC. Full DNS report: dns.pizza/domain/ns1.vodafone.cz · Age, certificate and blocklists: how.is/ns1.vodafone.cz · JSON: /api/v1/ns1.vodafone.cz