NSX preparation is a 4-step process.
Connect NSX Manager to vCenter Server. There is a one-to-one relationship between NSX Manager and vCenter Server.
Register with vCenter Server
Deploy NSX Controllers (Only required for logical switching, distributed routing, or edge service. If you are only using distributed firewallm(DFW), controllers are not required).
Host Preparation: Installs VIBs for VXLAN, DFW, and DLR on all hosts in the cluster. Configures the Rabbit MQ-based messaging infrastructure. Enables firewall. Notifies controllers that hosts are ready for NSX.
Configure IP pool settings and configure VXLAN: Creates a VTEP port group and VMKNICs on all hosts in the cluster. During this step, you can set the transport VLAN ID, teaming policy, and MTU.