For remote connectivity to Unix, Cisco and Juniper devices, Joval relies on the availability of SSH. If SSH is not available, Joval will be unable to connect.
Please make sure that the target device permits incoming SSH connections.
For remote connectivity to Windows, Joval uses the Windows Remote Management Framework (version 2.0 or higher). Therefore, if WinRM is unavailable on a target Windows machine Joval will be unable to connect.
If you are trying to add a Windows target, make sure that the Windows Remote Management service is active on the target machine. This service can be enabled using the command-line:
runas /u:Administrator "winrm qc"