nginx now offers experimental support for HTTP/3.

On FreeBSD, nginx is already compiled by default with that module (--with-http_v3_module included in nginx -V).

References:

• https://nginx.org/en/docs/http/ngx_http_v3_module.html
• https://cgit.freebsd.org/ports/commit/www/nginx/Makefile?id=f054a3856d6ba8527d2544f1a7d06eada1314987

OpenSSL version

$ ssh web-001 openssl -version
OpenSSL 3.5.4 30 Sep 2025 (Library: OpenSSL 3.5.4 30 Sep 2025)

Our OpenSSL library version allows to use 0-RTT.

Alt-Svc header

Per Wolfplex discussion, we could serve Alt-Svc headers on nginx

Kujiu suggests:
add_header Alt-Svc 'h3=":443"; ma=86400';

It's not clear if we should use h3 or h3-25.

Reference: https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Headers/Alt-Svc