
Step 1: Open up an instance of the Terminal app. Terminal can be found within the /Applications folder or by searching for it through Spotlight Search.
Step 2: At the command line in Terminal, type the following command and press enter:
defaults write com.apple.NetworkBrowser BrowseAllInterfaces 1
.Step 3: Still in the Terminal application, type the following command to restart Finder:
killall Finder
.Step 4: The process is now complete and AirDrop sharing should be supported on older Macs, as well as over an Ethernet connection.