GitHub and IPv6 in 2025

In this year 2025, the main GitHub domain still doesn’t serve over IPv6.

Some subdomains do have IPv6 though, just… not what you would expect.

For instance, avatars.githubusercontent.com:

; <<>> DiG 9.18.28-1~deb12u2-Debian <<>> AAAA avatars.githubusercontent.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 18015
;; flags: qr rd ra; QUERY: 1, ANSWER: 4, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 512
;; QUESTION SECTION:
;avatars.githubusercontent.com. IN      AAAA

;; ANSWER SECTION:
avatars.githubusercontent.com. 159 IN   AAAA    2606:50c0:8002::154
avatars.githubusercontent.com. 159 IN   AAAA    2606:50c0:8001::154
avatars.githubusercontent.com. 159 IN   AAAA    2606:50c0:8003::154
avatars.githubusercontent.com. 159 IN   AAAA    2606:50c0:8000::154

;; Query time: 32 msec
;; SERVER: 2a09::#53(2a09::) (UDP)
;; WHEN: Wed Jan 08 04:55:56 UTC 2025
;; MSG SIZE  rcvd: 170Code language: CSS (css)

Whereas none of the other domains accessed when accessing github.com (named github.com, github.githubassets.com and alive.github.com) has IPv6.

The package registry ghcr.io as well doesn’t support IPv6:

; <<>> DiG 9.18.28-1~deb12u2-Debian <<>> AAAA ghcr.io
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 967
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 512
; EDE: 29: (Result from negative cache)
;; QUESTION SECTION:
;ghcr.io.                       IN      AAAA

;; AUTHORITY SECTION:
ghcr.io.                547     IN      SOA     ns-773.awsdns-32.net. awsdns-hostmaster.amazon.com. 1 7200 900 1209600 86400

;; Query time: 32 msec
;; SERVER: 2a09::#53(2a09::) (UDP)
;; WHEN: Wed Jan 08 04:57:35 UTC 2025
;; MSG SIZE  rcvd: 152Code language: CSS (css)

And so does gist:

; <<>> DiG 9.18.28-1~deb12u2-Debian <<>> AAAA gist.github.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 52139
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 512
;; QUESTION SECTION:
;gist.github.com.               IN      AAAA

;; ANSWER SECTION:
gist.github.com.        1019    IN      CNAME   github.com.

;; AUTHORITY SECTION:
github.com.             182     IN      SOA     dns1.p08.nsone.net. hostmaster.nsone.net. 1656468023 43200 7200 1209600 3600

;; Query time: 32 msec
;; SERVER: 2a09::#53(2a09::) (UDP)
;; WHEN: Wed Jan 08 04:58:11 UTC 2025
;; MSG SIZE  rcvd: 123Code language: CSS (css)

So yeah, years later, always the same excuse, and no support at all.