networksetup -setdnsservers Wi-Fi 8.8.8.8
networksetup -setdnsservers Wi-Fi 208.67.222.222 208.67.220.220 8.8.8.8
networksetup -setdnsservers Wi-Fi Empty
networksetup -getdnsservers Wi-Fi
networksetup -setdnsservers Wi-Fi 8.8.8.8
networksetup -setdnsservers Wi-Fi 208.67.222.222 208.67.220.220 8.8.8.8
networksetup -setdnsservers Wi-Fi Empty
networksetup -getdnsservers Wi-Fi