Yes — flexireg.domains has IPv6.

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

C
IPv6 readiness
Works over IPv6, with gaps: www doesn't fully work over IPv6; its mail servers lack IPv6.
Website over IPv6
flexireg.domains has 2 IPv6 addresses and answers on every one we tested.
✓ 2a02:2090:1:3::4 answers · 443✓ 2a02:2090:1:4::4 answers · 443
yes
www over IPv6
www.flexireg.domains has no AAAA record.		no
Mail servers (MX) have IPv6
None of the mail servers has an AAAA record.
relay1.flexireg.net ✗relay2.flexireg.net ✗
no
Nameservers have IPv6
1 of 4 nameservers checked have an AAAA record, so IPv6-only resolvers can look the domain up.
ns3-geo.nic.ru ✗ns4-geo.nic.ru ✗ns8-geo.nic.ru ✗ans1-moscow.nic.ru ✓
yes

First measured 2026-11-04; last confirmed 2026-11-04.

HTTPS over IPv6 · not part of the grade yet
The certificate served over IPv6 at 2a02:2090:1:3::4 isn't valid for flexireg.domains: ERR_TLS_CERT_ALTNAME_INVALID.
https://flexireg.domains/ via 2a02:2090:1:3::4 · ERR_TLS_CERT_ALTNAME_INVALID
problem
 Which outside scripts, fonts, payments or chat flexireg.domains loads from have no IPv6.
 Load flexireg.domains over IPv6 from up to six other places — a second opinion.

What's keeping flexireg.domains from an A

  1. Add IPv6 for www.flexireg.domains
    www.flexireg.domains 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 flexireg.domains'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 2a02:2090:1:3::4 isn't valid for flexireg.domains: ERR_TLS_CERT_ALTNAME_INVALID. Often the IPv6 address points at a different server (or an old one) than IPv4 does. Make sure 2a02:2090:1:3::4 serves the same certificate as your IPv4 address.
  3. Mail servers without IPv6
    relay1.flexireg.net, relay2.flexireg.net have no AAAA record, so mail from IPv6-only servers can't reach them directly. If a provider runs your mail, that's their setting; if you run it, add AAAA records for these hosts.

Check again

flexireg.domains  Has IPv6

A (IPv4)31.177.76.15
31.177.80.15
AAAA (IPv6)2a02:2090:1:3::4
2a02:2090:1:4::4

www.flexireg.domains  IPv4 only

A (IPv4)31.177.76.15
31.177.80.15
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/6l9VgD7pen · How we measure

Checked 2026-11-15 15:50:19 UTC. Full DNS report: dns.pizza/domain/flexireg.domains · Age, certificate and blocklists: how.is/flexireg.domains · JSON: /api/v1/flexireg.domains