I've been noticing for a while now that the built-in macOS process nsurlsessiond uses a lot of bandwidth. No joke — about 30 MB / second for minutes, and then it stops for a while. This is without me doing anything. I was unaware of this until I enabled network monitoring in iStat Menus.
Today I felt enough is enough. I installed Little Snitch to see what is/was going on. Turns out that something in macOS is constantly, shamelessly downloading a lot of data from two particular domains:
Feels like a podcast problem doesn't it? For now, I'm blaming Podcast.app or its indexing service for not respecting network usage.
To mitigate the problem I've "blocked" those two domains at the OS level. It's not an elegant solution, but it seems to do the trick.
I no longer see the excessive high bandwidth usage.
Open a terminal window and edit the hosts file:
sudo nano /etc/hosts
Add the following lines:
ctrl+o to save, ctrl+x to exit.
And then flush your DNS cache:
sudo dscacheutil -flushcache
Btw, not a sponsored post : )