mDNSResponder and slow Wifi speed

Indeed that is true.

Hello iamnotnick, you were among the ones who had posted on my earlier threads about mDNSResponder.

And now - hello to the Apple moderators, or whoever did delete my threads.

TWO of my recent entries about the same problem (but with other details) within the last 24 hours completely disappeared from here. COMPLETELY DISAPPEARED as in, when you connect to the URL that you remember / had saved, it says ACCESS DENIED; this is the first one (old URL: https://discussions.apple.com/thread/251047152

and this is the second one (old URL: https://discussions.apple.com/thread/25103771):

Is this CENSORSHIP or is it a GLITCH or what is it?

Just to let you know, I have alerted Apple management in Germany about this - I am talking about the issue with mDNSResponder and about the apparent censorship of two threads without any apparent reason.

Now, I will refer to the actual issue I have with mDNSResponder below.

My own "case" with Apple Support is being escalated as we speak. A technical specialist has called already twice in the past four days and came up with interesting propositions to resolve the issue. He logged onto my machine last time 30 minutes ago) and together we went through several steps (terminal commands and more). Until now we haven't resolved the issue. But I have been told that the case is getting noticed and Apple is aware there is an issue - for a limited amount of Catalina users - with mDNSResponder and/or (!) with another process related/depending on it.

Of course, I will post any and all solutions and positive progress here and on my own original thread https://discussions.apple.com/thread/251039200.

Absolutely agree with iamnotnick.

After a week of re-installing systems and blaming everything from LittleSnitch to my provider, I stumbled upon mDNSReponder myself, force-quit it and had my problem resolved instantly.

Right after a fresh boot, my Wifi gives me 12-13Mbps in download (on an LTE line that achieves 65Mbps):

Force-quitting mDNSResponder and waiting for around 5 seconds, I get almost the maximum speed:

See What Is mDNSResponder, And Why Is It Running On My Mac? It is part of Bonjour and "regularly scans your local network looking for other Bonjour-enabled devices." This should result in momentary slower Wi-Fi during scans.

This is a issue, we've started a whole thread with all details and it suddenly disappeared without no reason. If you force closes -> activity -> network -> mDNSResponder and try again you have normal speeds. There is an issue for sure.

If I remember your other post your WiFi speeds are normal while in Safe Mode? If that is the case, that means one of the third-party apps is causing the slow down. Force quitting mDNSResponder causes whichever app to stop working.

Dirk van den Berg wrote:

Just to let you know, I have alerted Apple management in Germany about this - I am talking about the issue with mDNSResponder and about the apparent censorship of two threads without any apparent reason.

As I explained in your other post, you are not supposed to create multiple posts of the same issue. It has nothing to do with censorship. lol

Hi,

To be very honest, I just started a live session with support asking to clarify what's going on and why this chat has been deleted.

I've did some extensive testing today and this was the result when shutting down mDNSResponder. My speed went from 20Mb to 380Mbs... I tested this with several systems. So, why that thread has been deleted, shoot me.

Happy that you've chattered me, I could even not find the other threads as well. Very strange.

But one thing I'm sure off, mDNSResponder is not playing nice. I'm a developer so I've access to the latest beta... I think I'm going to take the jump to test if it occurs in the latest beta as well.

I disagree if it is done this way. I would gladly accept this if it were done in a transparent way, i.e. sending an email to the poster that briefly explains the reason why a post is deleted. It is something totally different to just discover your forum-entry has vanished into thin air without any explanation.

Hi Dirk,

The exact same thing is happening on my side. I'm working with support, did a clean install, installed OSX capture software to identify the issue. It seems it gets some attention and I'm more than able to verify that force closing mDNSresponder improves the internet speed A LOT. I will keep you posted as well.

A quick update: in my personal case, after installing the Catalina 10.15.3 Combo Updater the problem with slow WiFi speeds completely disappeared. I deduce that it had been entirely created by the previous version of macOS, 10.15.2. I might be wrong, but at least in my case it seems to be the only possible deduction.