Which Single Sign-On deployment mode should an administrator use for two 6.x vCenter Servers configured with linked mode?

Basic Single Sign-On with vCenter Server Heartbeat provides HA failover for a single vCenter instance and does not address the replication needs of a multi-vCenter Linked Mode topology.

Multisite Single Sign-On is the correct deployment mode for environments with multiple vCenter Servers in Linked Mode, as it enables Platform Services Controllers to replicate identity data across sites. This mode allows both vCenter Servers to share the same SSO domain while maintaining high availability and seamless authentication.

Basic Single Sign-On supports only a single vCenter Server and does not accommodate the replication requirements of Linked Mode.

'Single Sign-On with Linked Mode' is not a valid or recognized SSO deployment mode in vSphere 6.x documentation.