Right clic on network manager icon and select Edit Connections.
Select the Wired Connection and click on Edit
Select 802.1x Security tab, set parameters as in the image and click on save.
If the No Certificate Authority… message appear, Tick Don't warn me again and click on Ignore
Select IPv4 Settings tab, choose Automatic DHCP Method and click on save:
Select General tab untick All users may connect to this network, this prevent other user to use your connection. Note: due to a bug in the Ubuntu system, when another user wants to login, reboot the pc if you use 802.1x connection.
Click on Close button in the Network Connections Dialog.
Right clic on network manager icon and select Wired Connection.
The network manager icon should change as in the image: