Launch Terminal from Applications > Utilities folder.
Install Homebrew by entering the following command into the Terminal window:
/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"
Input your administrative password when prompted
Press RETURN to begin installation
**If you already have Homebrew installed, use the command "brew update" instead. This command may take some time to run.
Once Homebrew is installed, you can install telnet using the following command:
brew install telnet
You can now use telnet directly from Terminal. For example, telnet [ip address]. More details on how use to use telnet can be found by entering man telnet.