Stop Google Chrome from Using So Much Bandwidth at the CfA

I recently discovered that whenever I start Google Chrome at work, my computer’s bandwidth consumption goes to ~450 KiB/s and just sits there indefinitely. No matter what website I visit or anything.

Background downloads? Infinite loop?

No. mDNS. The CfA networks apparently transmit mDNS traffic between just about everybody, and it seems that there are so many mDNS-enabled machines that the traffic ends up being completely continuous.

This StackExchange answer ended up doing the trick for me. Apparently there are no user-facing, or even hidden, preferences to control the Chrome device discovery code that causes all of the traffic. You have create a “policy file” to alter the behavior:

echo '{ "EnableMediaRouter": false }' |sudo tee /etc/opt/chrome/policies/managed/no-mdns.json

It doesn’t happen on macOS because there Chrome hooks into the system mDNS implementation, which seems to be smarter about not polling everything all of the time.

Questions or comments? For better or worse this website isn’t interactive, so send me an email or, uh, Toot me.

See a list of all how-to guides.

On GitHub you can propose a revision to this guide or view its revision history.