User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:100.0) Gecko/20100101 Firefox/100.0

Steps to reproduce:

on mac. run the following command

launchctl unload /System/Library/LaunchDaemons/com.apple.mDNSResponder.plist

Actual results:

All the dns resolv on firefox are broken. (nightly = 99.0a1（2022-02-17）and 97.0.1（64 位元)

All try to enable dns-over-https feature. (Failed to resolv dns as well.)

Expected results:

Not sure shall dns resolve depend on a system service like mDNSResponder.
Safari get broken as well.
Chromium based brower works nomatter mDNSResponder enabled or not.

dig util could resolv domain name. but ping/curl couldn't work.

shit mac.

The Bugbug bot thinks this bug should belong to the 'Core::Networking: DNS' component, and is moving the bug to that component. Please revert this change in case you think the bot is wrong.

That's frustrating.
I wonder why Chromium would work if they use the same getaddrinfo.

(In reply to Zhong Yi Xiu from comment #0)

launchctl unload /System/Library/LaunchDaemons/com.apple.mDNSResponder.plist

On the bright side, my mac won't let me run this command if System Integrity Protection is engaged. So it's unlikely to be an issue for the majority of users.

+1, There're little user disable SIP.

I think this is mac's issue. DNS resolv should be indenpedent to mDNS.
Those mDNS packet in local network environment is annoying. : )
Also, It's really strange chroumium based browser not affect by the system-level apis. (I tested google-chrome-stable/edge stable by homebrew).

Thanks for your help.

Just find answer for this.

in the manpage of mDNSResponder

The DNS resolv on osx relayed on mDNSResponder.

But mDNSResponder do two things.

1. multicast dns
2. dns discovery

We can disable multicast dns by altering the preferences to disable multicastdns.

In short, the dns resolv relays on mdnsresponder (maybe the name is not show the truth, or maybe for osx mdns is more important than dns resolv)