Avaya failed to connect for the following reason unable to reach server

Avaya VPN failed to connect with following error message:

Failed to connect to server for the following reason : unable to reach server

Solution:

This error occurs if you are sharing your internet connection. To turn of the sharing follow below steps.

• Go to Control Panel\Network and Internet\Network and Sharing Center. You can simply copy paste the path in File Explorer. 
• Click on Local Area Connection under view your active networks.
• Click Properties.
• Click Sharing tab.
• Uncheck the Allow other network users to connect through this computer's internet connection.

This procedure is also applicable to Nortel VPN. Technically Avaya is the updated version of Nortel VPN. So you can resolve it using the same steps.