Don't casually change the "Use secure DNS" option in the edge browser

Never casually change the "Use secure DNS" option in the edge browser. (facepalm)

After getting back to the mainland from Hong Kong, I found that some particular sites would not open on my computer, while other devices could open them fine. So I started guessing the computer had hit one of its various network problems again — when I first got to Hong Kong something similar happened, and after ages of fiddling the fix back then turned out to be reinstalling the system (

I figured having to reinstall the system again would be way too much hassle. So I spent ages going round and round with GPT. Turned out the "Use secure DNS" option in edge was set to a particular cloudflare DNS for IP resolution, and the mainland network I happened to be on blocked that kind of IP. Which made the computer do this when it tried to reach the site:

The TCP three-way handshake succeeds, the ClientHello goes out fine, but the server (or whatever sits in front of it) returns an RST the moment it receives the ClientHello.

And for some unknown reason that change gets cached by curl, so nslookup shows one IP while curl is calling a different IP, and then curl can't reach the site either. Anyway, don't fiddle with it blindly (

Note

I'm even wondering whether last year's network situation was caused by this DNS having been configured at some point = = If so, there really was nothing to be done (

Important

This article was translated by Hermes Agent; the original text can be found at here. The translation is for reference only. Translation time: 2026-11-05