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Troubleshooting HTTP/3 in http.sys

tojens's avatar
tojens
Icon for Microsoft rankMicrosoft
Apr 01, 2022
HTTP/3 is a major change to HTTP. It switches away from using TCP as a transport and TLS separately to using QUIC as a transport which has TLS 1.3 or higher built in. These changes mean that migratin...
Published Apr 01, 2022
Version 1.0
http.sys
http3
QUIC
TLS 1.3
WS2022
tojens's avatar
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Technical PM for the Windows native HTTP stacks, IPv6 transition tech, and various IETF engagements
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Kimboslice's avatar
Kimboslice
Copper Contributor
Apr 18, 2024

Have you tried load testing QUIC on IIS? I (and others) am seeing a lot of errors in the http.sys log

See the following links for details
https://learn.microsoft.com/en-us/answers/questions/1515929/iis-quic-errors

https://stackoverflow.com/questions/74974001/http-3-fallback-on-iis-webserver This one seems related to POST, so perhaps not quite the same issue, though the same error is logged (Clearly, errors with QUIC are not reported well)

This is most definitely bugged. I cant say I would recommend anyone enable QUIC. I have been reporting this issue for 6+ months repeatedly.