Yes — ntp.org has IPv6.

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

B
IPv6 readiness
Works over IPv6, with one gap: its mail servers lack IPv6.
Website over IPv6
ntp.org has an AAAA record and answers on it.
✓ 2001:1838:2000:41b::80:0 answers · 443
yes
www over IPv6
www.ntp.org has 2 IPv6 addresses and answers on every one we tested.
✓ 2001:1838:2000:41b::80:0 answers · 443✓ 2001:5a8:601:7::80:0 answers · 443
yes
Mail servers (MX) have IPv6
None of the mail servers has an AAAA record.
mx0.chi1.ntfo.org ✗
no
Nameservers have IPv6
2 of 4 nameservers checked have an AAAA record, so IPv6-only resolvers can look the domain up.
ns1.everett.org ✓dns1.udel.edu ✗dns2.udel.edu ✗anyns.pch.net ✓
yes
HTTPS over IPv6 · not part of the grade yet
Loads over IPv6 with a valid certificate after 1 redirect: HTTP 200.
https://ntp.org/ via 2001:1838:2000:41b::80:0 → 302https://www.ntp.org/ via 2001:1838:2000:41b::80:0 → 200
works
 Load ntp.org over IPv6 from up to six other places — a second opinion.

What's keeping ntp.org from an A

  1. Mail servers without IPv6
    mx0.chi1.ntfo.org has no AAAA record, so mail from IPv6-only servers can't reach it directly. If a provider runs your mail, that's their setting; if you run it, add AAAA records for these hosts.

Check again

ntp.org  Has IPv6

A (IPv4)209.148.110.246
204.93.207.22
AAAA (IPv6)2001:1838:2000:41b::80:0

www.ntp.org  Has IPv6

A (IPv4)204.93.207.22
209.148.110.246
AAAA (IPv6)2001:1838:2000:41b::80:0
2001:5a8:601:7::80:0

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/OmNMnVsk9G · How we measure

Checked 2026-10-30 21:37:18 UTC. Full DNS report: dns.pizza/domain/ntp.org · JSON: /api/v1/ntp.org