Ubuntu 16.04 LTS ethernet Network 802.1x connect failed.

Ref. : http://askubuntu.com/questions/765021/ubuntu-16-04-doesnt-support-peap-authentication-without-ca-certificate

Please use nmcli to add the password.

1. Edit /etc/NetworkManager/system-connections/CONNECTION_NAME:

   [connection]
   id=CONNECTION_NAME
   
   [802-1x]
   password=YOUR_8021X_PASSWORD
   

2. Restart your network

   systemctl restart NetworkManager
   

3. You may need to bring the interface down and up to test the new changes:

   nmcli con down CONNECTION_NAME
   nmcli con up CONNECTION_NAME