Yes — cdn.constantcontact.com has IPv6.

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

This is a saved measurement from 2026-11-02 09:57 UTC. Check cdn.constantcontact.com live now

IPv6 readiness

Website, mail and DNS all work over IPv6.

Website over IPv6 cdn.constantcontact.com has 4 IPv6 addresses and answers on every one we tested (4 more not tested). ✓ 2600:9000:27ce:600:e:7aba:fec0:93a1 answers · 443✓ 2600:9000:27ce:e600:e:7aba:fec0:93a1 answers · 443✓ 2600:9000:27ce:4400:e:7aba:fec0:93a1 answers · 443✓ 2600:9000:27ce:f600:e:7aba:fec0:93a1 answers · 443– 2600:9000:27ce:2e00:e:7aba:fec0:93a1 not tested– 2600:9000:27ce:3a00:e:7aba:fec0:93a1 not tested– 2600:9000:27ce:e200:e:7aba:fec0:93a1 not tested– 2600:9000:27ce:4000:e:7aba:fec0:93a1 not tested	yes
Mail servers (MX) have IPv6 No MX records, so mail goes to the domain's own address (implicit MX). It has an AAAA record.	yes
Nameservers have IPv6 4 of 4 nameservers checked have an AAAA record, so IPv6-only resolvers can look the domain up. dns1.p01.nsone.net ✓dns2.p01.nsone.net ✓dns3.p01.nsone.net ✓dns4.p01.nsone.net ✓	yes

HTTPS over IPv6 · not part of the grade yet
Loads over IPv6 with a valid certificate: HTTP 403.

https://cdn.constantcontact.com/ via 2600:9000:27ce:600:e:7aba:fec0:93a1 → 403

works

Nothing keeping you from an A

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

Check again

cdn.constantcontact.com Has IPv6

Alias of	d3ia13pvjpp24b.cloudfront.net
A (IPv4)	3.167.99.104 3.167.99.121 3.167.99.11 3.167.99.105
AAAA (IPv6)	2600:9000:27ce:600:e:7aba:fec0:93a1 2600:9000:27ce:e600:e:7aba:fec0:93a1 2600:9000:27ce:4400:e:7aba:fec0:93a1 2600:9000:27ce:f600:e:7aba:fec0:93a1 2600:9000:27ce:2e00:e:7aba:fec0:93a1 2600:9000:27ce:3a00:e:7aba:fec0:93a1 2600:9000:27ce:e200:e:7aba:fec0:93a1 2600:9000:27ce:4000:e:7aba:fec0:93a1

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: cdn.constantcontact.com
Measured 2026-11-02 09:57:17 UTC by aaaa.bot (one server on Fly.io, region iad)

A (IPv4):    3.167.99.104, 3.167.99.121, 3.167.99.11, 3.167.99.105
AAAA (IPv6): 2600:9000:27ce:600:e:7aba:fec0:93a1, 2600:9000:27ce:e600:e:7aba:fec0:93a1, 2600:9000:27ce:4400:e:7aba:fec0:93a1, 2600:9000:27ce:f600:e:7aba:fec0:93a1, 2600:9000:27ce:2e00:e:7aba:fec0:93a1, 2600:9000:27ce:3a00:e:7aba:fec0:93a1, 2600:9000:27ce:e200:e:7aba:fec0:93a1, 2600:9000:27ce:4000:e:7aba:fec0:93a1

Readiness grade A: Website, mail and DNS all work over IPv6.
- Website over IPv6: cdn.constantcontact.com has 4 IPv6 addresses and answers on every one we tested (4 more not tested).
    2600:9000:27ce:600:e:7aba:fec0:93a1: answers (TCP 443)
    2600:9000:27ce:e600:e:7aba:fec0:93a1: answers (TCP 443)
    2600:9000:27ce:4400:e:7aba:fec0:93a1: answers (TCP 443)
    2600:9000:27ce:f600:e:7aba:fec0:93a1: answers (TCP 443)
    2600:9000:27ce:2e00:e:7aba:fec0:93a1: not tested
    2600:9000:27ce:3a00:e:7aba:fec0:93a1: not tested
    2600:9000:27ce:e200:e:7aba:fec0:93a1: not tested
    2600:9000:27ce:4000:e:7aba:fec0:93a1: not tested
- Mail servers (MX) have IPv6: No MX records, so mail goes to the domain's own address (implicit MX). It has an AAAA record.
- Nameservers have IPv6: 4 of 4 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 403.
    https://cdn.constantcontact.com/ via 2600:9000:27ce:600:e:7aba:fec0:93a1 -> HTTP 403, certificate: valid
DNS answers via DNS-over-HTTPS (Cloudflare). Method: https://aaaa.bot/method
Permanent link: https://aaaa.bot/r/4aHpo2noC6

Permanent link: aaaa.bot/r/4aHpo2noC6 · How we measure

Checked 2026-11-02 09:57:17 UTC. Full DNS report: dns.pizza/domain/cdn.constantcontact.com · JSON: /api/v1/cdn.constantcontact.com