Hi,

Does this only effect Github or all websites? Are you able to access https://mail.google.com and https://tls.ctf.network/version.php (in the latter case, if so what version does it return)?

Do you know if you have any firewall/network interception proxies/network devices on your network, we've occasionally seen this pop up due to badly acting network security devices.

Please provide Netlog and instructions can be found here : 
https://dev.chromium.org/for-testers/providing-network-details

@svaldez
this only effect to Github, gmail is normal, 
https://tls.ctf.network/version.php  => You are connecting with TLSv1.3 Experiment 2.

when i disable TLS 1.3 from chrome://flags/ ,i can access Github normaly, so i think this not from firewall from my network

@pbomm
 this is my chrome net log

Deleted: chrome-net-export-log.json 1.3 MB

chrome-net-export-log.json 1.3 MB View Download

Thanks for the NetLog! The log, however, does indeed suggest this is from something local. In the TLS 1.2 connection to github.com, it takes 247ms to get a response to the ClientHello. In the TLS 1.3-capable connection (TLS is backwards-compatible, so a correct TLS implementation will tolerate a TLS 1.2 ClientHello), we see that the connection is closed in 2ms.

That timing suggests something close to you is breaking the connection. Why it only happens on github.com, which hasn't deployed TLS 1.3 yet, is puzzling, but perhaps your firewall is configured to treat that site differently?

Thus, again, do you know if you have any firewall/network interception proxies/network devices on your network? We've had a host of problems this year with buggy networking middleware, so identifying what you're running is necessary to diagnose this.

Thanks!

> TLS is backwards-compatible, so a correct TLS implementation will tolerate a TLS 1.2 ClientHello

Sorry, I mistyped: A correct *TLS 1.2* implementation will tolerate a *TLS 1.3* ClientHello. Every TLS ClientHello is also a ClientHello for prior versions.

@kusnandar...: Any response to David's question in c#7 about firewalls?

Thank you for providing more feedback. Adding requester "davidben@chromium.org" to the cc list and removing "Needs-Feedback" label.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

kusnandartoni@ Can you please reply to comment #7, which will help in further triaging of this issue.

Thanks..

Archiving bug due to lack of response. kusnandartoni@, if you have the info requested in comment 7, please submit it in a new bug.