How do I determine the negotiated link speed for a network connection in Big Sur? How do I determine the negotiated link speed for a network connection in Big Sur?
Big Sur removed the handy Network Utility tool that displayed this information. This tool was powered by many standard Unix tools, most of which I can replicate. However, I cannot find how to determine the current link speed for my networking connection.
I'm not looking for the current transmission speed - this can be found in System Information. I want the link speed, which is the maximum theoretical transfer speed. Knowing this value can be handy when configuring a wifi network to make sure you are connected to the proper band, the band is configured right, and you aren't leaving any potential speed on the table.
I've seen suggestions to use ifconfig but this does not output any useful information.
$ ifconfig  en0 | grep media
$    media: autoselect
my suggestion (albeit very ugly) is to use the airport utility thats hidden in /System/Library/PrivateFrameworks/Apple80211.framework/Versions/Current/Resources, if you use 'airport -I' it will give you the max rate which I think is equivalent to the link speed. Hope that helps.