An administrator needs to add a stretched VLAN across two clusters in NDBWhich two prerequisites...

A stretched VLAN is a virtual network that spans across multiple Nutanix clusters and allows the communication between VMs on different clusters using the same subnet. A stretched VLAN can be used to provide high availability and load balancing for NDB components, such as HAProxy VMs, that require a virtual IP address (VIP) to be accessible from any cluster. To add a stretched VLAN across two clusters in NDB, the administrator needs to meet two prerequisites: the VLAN must be static and both clusters must be registered in NDB. A static VLAN is a VLAN that is manually created and configured by the administrator, as opposed to an IPAM VLAN that is automatically created and managed by NDB. A static VLAN can be added to a stretched VLAN in NDB, while an IPAM VLAN cannot. Both clusters must be registered in NDB before adding a stretched VLAN, as NDB needs to have the information and access to the clusters and their networks. The administrator can register the clusters in NDB using the Prism Element details, agent network configuration, and storage container information. The other option, Nutanix Cluster Management, is not a prerequisite for adding a stretched VLAN in NDB. Nutanix Cluster Management is a feature that allows the administrator to manage multiple Nutanix clusters from a single NDB UI, such as creating or deleting clusters, adding or removing nodes, or performing cluster operations. Nutanix Cluster Management is not required for adding a stretched VLAN, as the VLANs are created and configured in Prism Element, not in NDB. References:

Nutanix Certified Professional - Database Automation (NCP-DB) v6.5, Section 2 - Deploy and Configure an NDB Solution, Objective 2.3: Configure NDB High Availability

Nutanix Database Management & Automation (NDMA) Course, Module 3: Nutanix Database Service (NDB) Installation and Configuration, Lesson 3.3: Configuring NDB High Availability, Topic: NDB HA Architecture and Components

Nutanix Database Service High Availability Deployment Overview, Section: HAProxy VMs and Stretched VLANs

[Configuring a Virtual NIC to Operate in Access or Trunk Mode - Nutanix], Section: Creating a vNIC in Access or Trunk Mode