Network Utility was an application included with macOS up to MacOS Catalina that provided a variety of tools that could be used related to computer network information gathering and analysis. Starting with macOS Big Sur the application is no longer included and was replaced with a message that it has been deprecated .
Network Utility shows information about each of your network connections, including the Mac Address of the interface, the IP address assigned to it, its speed and status, a count of data packets sent and received, and a count of transmission errors and collisions.
The available services or tools found in the Network Utility:
Examples of what the Network Utility can help with:
Network Utility uses the tools supplied in the unix directories for most of its functions, however for the port scan it uses a unix executable in its resources folder, stroke, found at Network Utility.app/Contents/Resources/stroke.