ACCESSING AN AUTHENTICATION SERVICE FROM A CLOUD DOMAIN IN A NETWORK ZONE DIFFERENT FROM THAT OF THE AUTHENTICATION SERVICE

A method of establishing a secure communication channel from a first edge device that is in a first network zone across a secure overlay network to a second edge device that is in a second network zone, so that access to a computing device that is in the second network zone can be authenticated by an authentication service that is in the first network zone, includes the steps of establishing a first secure communication channel from the first edge device to the secure overlay network, receiving a request to join the secure overlay network along with administrator credential information and, responsive to the request, transmitting the administrator credential information to the authentication service for authentication through the first secure communication channel and the first edge device, and establishing a second secure communication channel from the second edge device to the secure overlay network if the authentication is received from the authentication service.