cloudflare.com advertises HTTP/3 in its HTTPS DNS record, so browsers can use HTTP/3 on the first connection. https://savearoundtrip.com/?d=cloudflare.com#check
savearoundtrip

Publish an HTTPS DNS record. Let browsers reach HTTP/3 on the first connection instead of wasting a round trip.

@bortzmeyer je découvre ce record, ça marche avec les cname?

@gduchaussois Les CNAME fonctionnent par nom, pas par type et donc oui.

https://www.bortzmeyer.org/9460.html

Blog Stéphane Bortzmeyer: RFC 9460: Service Binding and Parameter Specification via the DNS (SVCB and HTTPS Resource Records)