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mDNSresponder sucking bandwidth

My computer has become increasingly sluggish recently. Took a glance at Activity Monitor and mDNSresponder has downloaded some 14 gigs?! My understanding is that this is part of the 'Bonjour Protocol.' What is this program doing???

Any help is appreciated.

thank you

-m

OS is

Sierra

10.12.6 (can't update for fear it will break my Adobe Suite worse than the previous update did)

running on

MacBook Air

1.8 GHz Intel Core i5

4 GB 1600 MHz DDR3

Intel HD Graphics 4000 1536 MB

MacBook Air 13″, macOS 10.12

Posted on Jan 20, 2021 6:13 PM

Best reply

a brody

Level 10

83,125 points

Posted on Feb 6, 2021 1:38 PM

mDNSRespondor is a key part of Bonjour. Bonjour is the "discovery" application that lets wireless devices find each other automatically. When it goes out of control, either your wireless router is not setup right, or you have multiple requests for Handoff happening, or you have too many wireless devices burdening the machine with a response.

The best thing to do is to turn off Bluetooth, use a wired keyboard and mouse, and see if the issue drops off when you also turn off your printer. If none of those seems to resolve the issue, and you have no other computers, tablets, or phones in the household, go to Apple menu -> System Preferences -> Sharing, and make sure everything is unchecked. You only want sharing on when you need it.

Use Etrecheck to help isolate further if you installed something that shouldn't have been installed:

https://discussions.apple.com/docs/DOC-250002463

And backup your data.

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mDNSresponder sucking bandwidth

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