After installing Windows Server 2012 Core, the easiest way to setup the server is to remotely administer Server Core using the System Manager tool. However, by default this is blocked by the Windows Firewall, so you have to enable remote administration on Server Core before you can administer it. To enable remote administration on Windows Server 2012 Core, run the following command:
netsh advfirewall set rule group=”remote administration” new enable=yes
Note that if you are using a 3rd party firewall, you may be having trouble if the Windows Firewall has turned itself back on again and in this case you should disable Windows Firewall if you plan to continue using the 3rd party firewall. To disable the Windows Firewall, to enable remote administration of the Windows Server 2012 Core computer, use the following command:
netsh advfirewall set allprofiles state off
To reset the Windows Firewall back to the default, use the following command:
netsh advfirewall reset
Resetting the Windows Firewall can be useful if it’s not clear how the firewall is set because Windows Server 2012 Core doesn’t have a GUI and you are not able to remotely administer the machine.