HTTP/3 issues on Windows 10/11
For some reason I looked into whether my Firefoxes are ever using HTTP/3 - turns out they aren't. I looked up how to get any kind of information on this, and saved networking logs. They indicate that the moment Firefox tries to send the first UDP packet for the HTTP/3 connection, it gets "ErrorAccordingToNSPR [in=-5987 out=80004005]", the connection fails, and the server is added to an exclusion list so that no further (futile) attempts at using HTTP/3 will be made (which makes reattempting a HTTP/3 connection by hand that much harder). The initial platform was Windows 11, with Firefox 98.0.2, but afterwards I reproduced the issue on another PC running Windows 10, and with a nightly version on Windows 11, which I also used to save some logs which I can publish, as they don't reveal the sites I visit (though I can always provide the logs from my everyday instance of Firefox, should you find the information insufficient).
I also confirmed that HTTP/3 works with Chromium on the very same system and network, and also with Firefox on another machine running Linux.
All Replies (6)
quic.rocks:4433, quic.nginx.org, cloudflare-quic.com, and also sites known to be using HTTP/3, such as Google services, Facebook, etc.
I also made the "sterile" log from Firefox Nightly available at http://plain.hylobat.es/log.txt-main.22732.moz_log.gz.
Modified
You can create a new profile as a quick test to see if your current profile is causing the problem.
See "Creating a profile":
If the new profile works then you can transfer files from a previously used profile to the new profile, but be cautious not to copy corrupted files to avoid carrying over problems.
cor-el said
You can create a new profile as a quick test to see if your current profile is causing the problem.
The same issue occurred on a completely new profile with nightly. I haven't attempted a new profile with stable - I will, shortly. upd: yup, HTTP/3 doesn't work with a new profile either. See the log linked in my other reply for details as to what, and how, "doesn't work".
Modified
Does the proxy setting matter -- Use system setting vs autodetect vs No proxy?
jscher2000 powiedział
Does the proxy setting matter -- Use system setting vs autodetect vs No proxy?
It doesn't seem so. I tried all three variants, recreating a profile each time.
Although the standard may not be finalized and published at IETF as a standard, it a) is implemented and enabled by default in Firefox and other browsers and b) works in my setup with other browsers, as well as with Firefox on Linux.
This is a matter of finding out the reason for why Firefox can't use UDP on my Windows machines (attempting to establish a QUIC connection results in an error from the OS), and the issue may very well not be with Firefox at all.