Yes — sourceforge.net 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 sourceforge.net has 2 IPv6 addresses and answers on every one we tested. ✓ 2606:4700::6812:c95 answers · 443✓ 2606:4700::6812:d95 answers · 443	yes
www over IPv6 www.sourceforge.net has 2 IPv6 addresses and answers on every one we tested. ✓ 2606:4700::6812:c95 answers · 443✓ 2606:4700::6812:d95 answers · 443	yes
Mail servers (MX) have IPv6 None of the mail servers has an AAAA record. mx.sourceforge.net ✗	no
Nameservers have IPv6 6 of 6 nameservers checked have an AAAA record, so IPv6-only resolvers can look the domain up. ns21.constellix.com ✓ns31.constellix.com ✓ns41.constellix.net ✓ns51.constellix.net ✓ns61.constellix.net ✓ns11.constellix.com ✓	yes

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

https://sourceforge.net/ via 2606:4700::6812:c95 → 200

works

What's keeping sourceforge.net from an A

Mail servers without IPv6
mx.sourceforge.net 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.

Check again

sourceforge.net Has IPv6

A (IPv4)	104.18.13.149 104.18.12.149
AAAA (IPv6)	2606:4700::6812:c95 2606:4700::6812:d95

www.sourceforge.net Has IPv6

Alias of	www.sourceforge.net.cdn.cloudflare.net
A (IPv4)	104.18.12.149 104.18.13.149
AAAA (IPv6)	2606:4700::6812:c95 2606:4700::6812:d95

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: sourceforge.net
Measured 2026-10-30 19:04:31 UTC by aaaa.bot (one server on Fly.io, region iad)

A (IPv4):    104.18.13.149, 104.18.12.149
AAAA (IPv6): 2606:4700::6812:c95, 2606:4700::6812:d95
www AAAA:    2606:4700::6812:c95, 2606:4700::6812:d95

Readiness grade B: Works over IPv6, with one gap: its mail servers lack IPv6.
- Website over IPv6: sourceforge.net has 2 IPv6 addresses and answers on every one we tested.
    2606:4700::6812:c95: answers (TCP 443)
    2606:4700::6812:d95: answers (TCP 443)
- www over IPv6: www.sourceforge.net has 2 IPv6 addresses and answers on every one we tested.
    2606:4700::6812:c95: answers (TCP 443)
    2606:4700::6812:d95: answers (TCP 443)
- Mail servers (MX) have IPv6: None of the mail servers has an AAAA record.
- Nameservers have IPv6: 6 of 6 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 200.
    https://sourceforge.net/ via 2606:4700::6812:c95 -> HTTP 200, certificate: valid
DNS answers via DNS-over-HTTPS (Cloudflare). Method: https://aaaa.bot/method
Permanent link: https://aaaa.bot/r/TQOY_dF3hh

Permanent link: aaaa.bot/r/TQOY_dF3hh · How we measure

Checked 2026-10-30 19:04:31 UTC — one of the top 1,000 sites, re-checked weekly. Re-check now. Full DNS report: dns.pizza/domain/sourceforge.net · JSON: /api/v1/sourceforge.net