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Tag: kestrel

3 posts

2026-08-02 csharp dotnet dotnet-11

How to configure Kestrel to serve HTTP/3 in ASP.NET Core 11

A complete guide to enabling HTTP/3 on Kestrel in ASP.NET Core 11: the HttpProtocols.Http1AndHttp2AndHttp3 endpoint config, MsQuic platform requirements on Windows, Linux, and macOS, why the first request is never HTTP/3, how to verify with HttpClient and middleware, QuicTransportOptions tuning, and the firewall and proxy gotchas that make it silently fall back.

2026-05-12 errors csharp dotnet

Fix: InvalidOperationException: Synchronous operations are disallowed

Replace the Stream.Read or Write call with ReadAsync/WriteAsync. As a last resort, set AllowSynchronousIO on Kestrel, IIS, or per-request via IHttpBodyControlFeature.

2026-04-20 dotnet-11 aspnet-core kestrel

Kestrel starts processing HTTP/3 requests before the SETTINGS frame in .NET 11 Preview 3

.NET 11 Preview 3 lets Kestrel serve HTTP/3 requests before the peer's control stream and SETTINGS frame arrive, shaving handshake latency off the first request on every new QUIC connection.