Yes — weillcornell.org has IPv6.

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

This is a saved measurement from 2026-11-04 17:34 UTC. Check weillcornell.org live now

IPv6 readiness

Works over IPv6, with gaps: its mail servers lack IPv6; its nameservers lack IPv6.

Website over IPv6 weillcornell.org has 2 IPv6 addresses and answers on every one we tested. ✓ 2620:12a:8000::4 answers · 443✓ 2620:12a:8001::4 answers · 443	yes
www over IPv6 www.weillcornell.org has 2 IPv6 addresses and answers on every one we tested. ✓ 2620:12a:8000::4 answers · 443✓ 2620:12a:8001::4 answers · 443	yes
Mail servers (MX) have IPv6 None of the mail servers has an AAAA record. inbound-smtp.us-east-1.amazonaws.com ✗	no
Nameservers have IPv6 No nameserver has an AAAA record — an IPv6-only resolver can't reach this domain's DNS. azr-iblxext1.med.cornell.edu ✗lex-iblxext1.med.cornell.edu ✗york-iblxext1.med.cornell.edu ✗	no

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

https://weillcornell.org/ via 2620:12a:8000::4 → 200

works

What's keeping weillcornell.org from an A

Mail servers without IPv6
inbound-smtp.us-east-1.amazonaws.com 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.
Nameservers without IPv6
azr-iblxext1.med.cornell.edu, lex-iblxext1.med.cornell.edu, york-iblxext1.med.cornell.edu all have no AAAA record, so a resolver that only speaks IPv6 can't look your domain up. Most DNS providers offer IPv6 nameservers; ask yours, or move DNS to one that does.

Check again

weillcornell.org Has IPv6

A (IPv4)	23.185.0.4
AAAA (IPv6)	2620:12a:8000::4 2620:12a:8001::4

www.weillcornell.org Has IPv6

Alias of	live-wcmc-pops.pantheonsite.io → fe4.edge.pantheon.io
A (IPv4)	23.185.0.4
AAAA (IPv6)	2620:12a:8000::4 2620:12a:8001::4

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: weillcornell.org
Measured 2026-11-04 17:34:21 UTC by aaaa.bot (one server on Fly.io, region iad)

A (IPv4):    23.185.0.4
AAAA (IPv6): 2620:12a:8000::4, 2620:12a:8001::4
www AAAA:    2620:12a:8000::4, 2620:12a:8001::4

Readiness grade C: Works over IPv6, with gaps: its mail servers lack IPv6; its nameservers lack IPv6.
- Website over IPv6: weillcornell.org has 2 IPv6 addresses and answers on every one we tested.
    2620:12a:8000::4: answers (TCP 443)
    2620:12a:8001::4: answers (TCP 443)
- www over IPv6: www.weillcornell.org has 2 IPv6 addresses and answers on every one we tested.
    2620:12a:8000::4: answers (TCP 443)
    2620:12a:8001::4: answers (TCP 443)
- Mail servers (MX) have IPv6: None of the mail servers has an AAAA record.
- Nameservers have IPv6: No nameserver has an AAAA record — an IPv6-only resolver can't reach this domain's DNS.

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

HTTPS over IPv6 (not graded): Loads over IPv6 with a valid certificate: HTTP 200.
    https://weillcornell.org/ via 2620:12a:8000::4 -> HTTP 200, certificate: valid
DNS answers via DNS-over-HTTPS (Cloudflare). Method: https://aaaa.bot/method
Permanent link: https://aaaa.bot/r/tdCqkRLF3_

Permanent link: aaaa.bot/r/tdCqkRLF3_ · How we measure

Checked 2026-11-04 17:34:21 UTC. Full DNS report: dns.pizza/domain/weillcornell.org · Age, certificate and blocklists: how.is/weillcornell.org · JSON: /api/v1/weillcornell.org