Network Link Conditioner not working on macOS Sierra
This issue is fixed in the latest version of the Network Link Conditioner - it's in the "Additional Tools for Xcode 8.1" download from https://developer.apple.com/download/more/.
I've tested all the built-in profiles and they work as expected.
I can't comment (not enough reputation), but figured I'd add that the Xcode 8 tools that have the Network Link Conditioner in it has changed names.
https://developer.apple.com/download/more/
It's now in the "Additional Tools for Xcode 8", instead of "Hardware IO Tools for Xcode 7.x".
Though, that didn't fix any of the issues...
Step 1: Uninstall Old NLC by right clicking ("remove") it in "System Preference"
Delete Network link conditioner
Step 2:
Open https://developer.apple.com/download/more/ , login to apple account and search for additional tools and Download Additional Tools for Xcode 9
.
Tested default and my existing custom profiles, all worked like a charm!