Yes — ietf.org has IPv6.

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

IPv6 readiness

Website, mail and DNS all work over IPv6.

Website over IPv6 ietf.org has 2 IPv6 addresses and answers on every one we tested. ✓ 2606:4700::6810:2c63 answers · 443✓ 2606:4700::6810:2d63 answers · 443	yes
www over IPv6 www.ietf.org has 2 IPv6 addresses and answers on every one we tested. ✓ 2606:4700::6810:2c63 answers · 443✓ 2606:4700::6810:2d63 answers · 443	yes
Mail servers (MX) have IPv6 Every mail server has an AAAA record. mx.ietf.org ✓	yes
Nameservers have IPv6 2 of 2 nameservers checked have an AAAA record, so IPv6-only resolvers can look the domain up. ken.ns.cloudflare.com ✓jill.ns.cloudflare.com ✓	yes

HTTPS over IPv6 · not part of the grade yet
Loads over IPv6 with a valid certificate after 1 redirect: HTTP 200.

https://ietf.org/ via 2606:4700::6810:2c63 → 301https://www.ietf.org/ via 2606:4700::6810:2c63 → 200

works

Nothing keeping you from an A

Nothing to fix
Show it off: add the badge to your README.
[![IPv6](https://aaaa.bot/badge/ietf.org.svg)](https://aaaa.bot/ietf.org)

Check again

ietf.org Has IPv6

A (IPv4)	104.16.44.99 104.16.45.99
AAAA (IPv6)	2606:4700::6810:2c63 2606:4700::6810:2d63

www.ietf.org Has IPv6

A (IPv4)	104.16.44.99 104.16.45.99
AAAA (IPv6)	2606:4700::6810:2c63 2606:4700::6810:2d63

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: ietf.org
Measured 2026-10-30 23:04:30 UTC by aaaa.bot (one server on Fly.io, region iad)

A (IPv4):    104.16.44.99, 104.16.45.99
AAAA (IPv6): 2606:4700::6810:2c63, 2606:4700::6810:2d63
www AAAA:    2606:4700::6810:2c63, 2606:4700::6810:2d63

Readiness grade A: Website, mail and DNS all work over IPv6.
- Website over IPv6: ietf.org has 2 IPv6 addresses and answers on every one we tested.
    2606:4700::6810:2c63: answers (TCP 443)
    2606:4700::6810:2d63: answers (TCP 443)
- www over IPv6: www.ietf.org has 2 IPv6 addresses and answers on every one we tested.
    2606:4700::6810:2c63: answers (TCP 443)
    2606:4700::6810:2d63: answers (TCP 443)
- Mail servers (MX) have IPv6: Every mail server 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 after 1 redirect: HTTP 200.
    https://ietf.org/ via 2606:4700::6810:2c63 -> HTTP 301, certificate: valid
    https://www.ietf.org/ via 2606:4700::6810:2c63 -> HTTP 200, certificate: valid
DNS answers via DNS-over-HTTPS (Cloudflare). Method: https://aaaa.bot/method
Permanent link: https://aaaa.bot/r/Z9AonbJIBm

Permanent link: aaaa.bot/r/Z9AonbJIBm · How we measure

Checked 2026-10-30 23:04:30 UTC — one of the top 1,000 sites, re-checked weekly. Re-check now. Full DNS report: dns.pizza/domain/ietf.org · JSON: /api/v1/ietf.org