Yes — login-auth-microsoft.com has IPv6.

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

IPv6 readiness

Works over IPv6, with one gap: its mail servers lack IPv6.

Website over IPv6 login-auth-microsoft.com has 2 IPv6 addresses and answers on every one we tested. ✓ 2606:4700:3032::ac43:85d6 answers · 443✓ 2606:4700:3034::6815:5cf answers · 443	yes
www over IPv6 www.login-auth-microsoft.com has 2 IPv6 addresses and answers on every one we tested. ✓ 2606:4700:3032::ac43:85d6 answers · 443✓ 2606:4700:3034::6815:5cf answers · 443	yes
Mail servers (MX) have IPv6 None of the mail servers has an AAAA record. mail.login-auth-microsoft.com ✗_dc-mx.81f58d48fe0a.login-auth-microsoft.com ✗	no
Nameservers have IPv6 2 of 2 nameservers checked have an AAAA record, so IPv6-only resolvers can look the domain up. annalise.ns.cloudflare.com ✓guss.ns.cloudflare.com ✓	yes

HTTPS over IPv6 · not part of the grade yet
Loads over IPv6 with a valid certificate: HTTP 404.

https://login-auth-microsoft.com/ via 2606:4700:3032::ac43:85d6 → 404

works

What's keeping login-auth-microsoft.com from an A

Mail servers without IPv6
mail.login-auth-microsoft.com, _dc-mx.81f58d48fe0a.login-auth-microsoft.com 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

A (IPv4)	172.67.133.214 104.21.5.207
AAAA (IPv6)	2606:4700:3032::ac43:85d6 2606:4700:3034::6815:5cf

www.login-auth-microsoft.com Has IPv6

A (IPv4)	172.67.133.214 104.21.5.207
AAAA (IPv6)	2606:4700:3032::ac43:85d6 2606:4700:3034::6815:5cf

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

IPv6 measurement: login-auth-microsoft.com
Measured 2026-11-11 22:26:12 UTC by aaaa.bot (one server on Fly.io, region iad)

A (IPv4):    172.67.133.214, 104.21.5.207
AAAA (IPv6): 2606:4700:3032::ac43:85d6, 2606:4700:3034::6815:5cf
www AAAA:    2606:4700:3032::ac43:85d6, 2606:4700:3034::6815:5cf

Readiness grade B: Works over IPv6, with one gap: its mail servers lack IPv6.
- Website over IPv6: login-auth-microsoft.com has 2 IPv6 addresses and answers on every one we tested.
    2606:4700:3032::ac43:85d6: answers (TCP 443)
    2606:4700:3034::6815:5cf: answers (TCP 443)
- www over IPv6: www.login-auth-microsoft.com has 2 IPv6 addresses and answers on every one we tested.
    2606:4700:3032::ac43:85d6: answers (TCP 443)
    2606:4700:3034::6815:5cf: answers (TCP 443)
- Mail servers (MX) have IPv6: None of the mail servers has an AAAA record.
- Nameservers have IPv6: 2 of 2 nameservers checked have an AAAA record, so IPv6-only resolvers can look the domain up.

Reachability = a TCP connection opened on port 443 (or 80).

HTTPS over IPv6 (not graded): Loads over IPv6 with a valid certificate: HTTP 404.
    https://login-auth-microsoft.com/ via 2606:4700:3032::ac43:85d6 -> HTTP 404, certificate: valid
DNS answers via DNS-over-HTTPS (Cloudflare). Method: https://aaaa.bot/method
Permanent link: https://aaaa.bot/r/qWGPtr8NnZ

Permanent link: aaaa.bot/r/qWGPtr8NnZ · How we measure

Checked 2026-11-11 22:26:12 UTC. Full DNS report: dns.pizza/domain/login-auth-microsoft.com · Age, certificate and blocklists: how.is/login-auth-microsoft.com · JSON: /api/v1/login-auth-microsoft.com