If your Mac can’t connect to another computer
If a shared computer or server doesn’t appear on the desktop or in the Finder sidebar or if you can’t connect to it using Go > Connect to Server, try these suggestions.
Check Finder preferences
In the Finder on your Mac, choose Finder > Preferences.
Click General, then make sure the “Connected servers” tickbox is selected.
Click Sidebar, then make sure the “Connected servers” tickbox is selected.
Make sure you’re looking for the correct name
You may need to look for the computer’s DNS name or IP address rather than the name of the computer.
Ask your network administrator how to connect to the computer you’re looking for.
Make sure the computer or server is available
The computer or server may have been shut down or restarted, or may have been disconnected from the network.
Try reconnecting, or contact the person who administers the computer or server.
If the computer is using Bonjour or is a Windows (SMB/CIFS) server, make sure it’s on the same local network or subnetwork as your Mac.
If a Windows (SMB/CIFS) server has the Internet Connection Firewall turned on, you may not be able to connect to it.
Note: If the computer is not on your local network or subnetwork, you may be able to connect to it by choosing Go > Connect to Server and typing its address in the Connect to Server dialogue.
Check your network connection
Your Mac may be disconnected from the network.
To check your connection, choose Apple menu > System Preferences, then click Network . The indicator next to your type of network connection should be green.
Note: To connect, the server or shared computer and your Mac must be on the same network or, if you’re using Go > Connect to Server, make sure they’re both connected to the Internet and aren’t connected to private networks.
For help connecting to a shared computer or server, contact the person who owns the computer or your network administrator.