How communication with legacy media servers happens in the case of cloud configuration
If the Enable insecure communication with NetBackup 8.0 and earlier hosts option is disabled, NetBackup cannot communicate with legacy media servers that you use for cloud storage irrespective of the value of the CSSC_LEGACY_AUTH_ENABLED cloud configuration option.
The Enable insecure communication with NetBackup 8.0 and earlier hosts option is available in the NetBackup Administration Console on the Security Management > Global Security Settings > Secure Communication tab.