Yes — ftp.planeo.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
ftp.planeo.cz has an AAAA record and answers on it.
✓ 2a00:19a0:3:74:0:d9c6:74bc:1 answers · 443
yes
www over IPv6
www.ftp.planeo.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.
duke.ns.cloudflare.com ✓teagan.ns.cloudflare.com ✓
yes
HTTPS over IPv6 · not part of the grade yet
The certificate served over IPv6 at 2a00:19a0:3:74:0:d9c6:74bc:1 isn't valid for ftp.planeo.cz: DEPTH_ZERO_SELF_SIGNED_CERT.
https://ftp.planeo.cz/ via 2a00:19a0:3:74:0:d9c6:74bc:1 · DEPTH_ZERO_SELF_SIGNED_CERT
problem
 Which outside scripts, fonts, payments or chat ftp.planeo.cz loads from have no IPv6.
 Load ftp.planeo.cz over IPv6 from up to six other places — a second opinion.

What's keeping ftp.planeo.cz from an A

  1. Add IPv6 for www.ftp.planeo.cz
    www.ftp.planeo.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 ftp.planeo.cz's AAAA record(s) for www. How to add an AAAA record
  2. The certificate served over IPv6 is wrong
    The certificate served over IPv6 at 2a00:19a0:3:74:0:d9c6:74bc:1 isn't valid for ftp.planeo.cz: DEPTH_ZERO_SELF_SIGNED_CERT. Often the IPv6 address points at a different server (or an old one) than IPv4 does. Make sure 2a00:19a0:3:74:0:d9c6:74bc:1 serves the same certificate as your IPv4 address.

Check again

ftp.planeo.cz  Has IPv6

A (IPv4)217.198.116.188
AAAA (IPv6)2a00:19a0:3:74:0:d9c6:74bc:1

www.ftp.planeo.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/dgKlil5KT5 · How we measure

Checked 2026-11-15 17:02:32 UTC. Full DNS report: dns.pizza/domain/ftp.planeo.cz · Age, certificate and blocklists: how.is/ftp.planeo.cz · JSON: /api/v1/ftp.planeo.cz