The SDDC virtual infrastructure consists of workload domains. The SDDC virtual infrastructure includes a management workload domain that contains the management cluster and a virtual infrastructure workload domain that contains the shared edge and compute cluster.
The management cluster runs the virtual machines that manage the SDDC. These virtual machines host vCenter Server, vSphere Update Manager, NSX Manager, and other management components. All management, monitoring, and infrastructure services are provisioned to a vSphere cluster which provides high availability for these critical services. Permissions on the management cluster limit access only to administrators. This limitation protects the virtual machines that are running the management, monitoring, and infrastructure services from unauthorized access. The management cluster leverages software-defined networking capabilities in NSX for vSphere.
The management cluster architecture and design is covered in the VMware Validated Design for Software-Defined Data Center. The NSX-T validated design does not include the design of the management cluster.
Shared Edge and Compute Cluster
The shared edge and compute cluster runs the NSX-T controllers, edge virtual machines and all tenant workloads. The edge virtual machines are responsible for North-South routing between compute workloads and the external network. This is often referred to as the on-off ramp of the SDDC.
The hosts in this cluster provide services such as high availability to the NSX-T controllers and edge virtual machines.