How to get Link Speed now that Network Utility is gone?

robertfromadelphi wrote:

Now that Network Utility is gone in Big Sur, any suggested alternative ways to acquire Link Speed for Ethernet interfaces?

How about from Terminal.app (?)

ex. interface name is en0, copy and paste:

ifconfig  en0 | grep media

If not you can see more:

 man ifconfig | more

How about >(Option key)System Information>Hardware>Ethernet

https://support.apple.com/guide/mac-help/use-gigabit-ethernet-on-mac-mchlp2779/mac

With the demise of the Network Utility in Big Sur, you can verify your wireless link speed (actually transmission rate) by just using the option key while clicking on the Wi-Fi icon in the menu bar. If you are not using Wi-Fi, then the link speed is the fixed Ethernet controller rating (e.g. 1 Gb/s or 1000BaseT).

The following AppleScript when copy/pasted into Script Editor will determine if your Wi-Fi is running, and if so, provide the last transmisson rate sampled. If Wi-Fi is not running, then it will report the hardware capability of your Ethernet chip (e.g. 1000BaseT).

use scripting additions

set airport to "/System/Library/PrivateFrameworks/Apple80211.framework/Versions/Current/Resources/airport"
set runstate to (do shell script airport & " -I | awk '/state:/ {$1=$1;print $2}'")
if not runstate = "" then
	set txRate to (do shell script airport & " -I | awk '/lastTxRate:/ {$1=$1;print $2}'")
	display dialog "Last wireless transmission rate (Mbps): " & txRate with title "Wireless Tx Rate"
else
	
	set linkspeed to (do shell script "ifconfig -a | sed -En 's/.*\\(([0-9]*baseT).*/\\1/p'")
	display dialog "Link speed on active interface: " & linkspeed with title "Link Speed"
end if
return

Tested on Big Sur 11.0.1 on an M1 Mac mini.