Disabling Bonjour on Mac OS. Reduce some of the noise on my… | by Teri Radichel | Cloud Security | September 2023


Reduce some of the noise on my network

I’ve written here about all the noise that Apple’s operating system generates. I’m still trying to figure out how to disable this stuff on a laptop where I don’t need all this nonsense – where I work.

One of these noisy features is all traffic on port 5353. I don’t need to automatically connect to things or share my video to my TV and such on my work computers.

Maybe I’ll regret it when I need to print, but I can always turn this option back on if and when I need it, which is rare. Or I could have a separate computer for printing that doesn’t have this feature disabled. I’ll probably opt for the latter.

After searching and searching, I finally figured out how to disable this feature.

I actually found it on the Tenable site which recommends turning off this service if you don’t need it – probably based on some presentations at Defcon or BlackHat if memory serves.

Here is the command to disable this service.

sudo defaults write /Library/Preferences/com.apple.mDNSResponder.plist NoMulticastAdvertisements -bool true

I wrote here how to create a configuration file to run at startup:

I’m not really sure if this is required, but to make sure it stays disabled you can add it to this file.

Well, unfortunately, after this change I still see traffic blocked on port 5353, but at least that’s one less thing to worry about.

Traffic is greatly reduced.

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