Each NSX Manager has a 1:1 relationship with vCenter Server. Therefore, two NSX Managers are created in the management cluster. Figure 7 shows how the NSX Manager is used in a two-pod design.
The first NSX Manager in the Management pod is solely responsible for deploying and operating the highly available ESG instances that provide load balancing functionality. Every component in the management cluster, which relies on multiple external services such as Platform Services Controllers and vCloud Director cells, uses the ESG as a load balancer to ensure reachability should a component fail.
The second NSX Manager in the Management pod is responsible for all Edge / Resource pod networking. It is registered with vCloud Director to provide networking services to tenants, including stateful firewalls and load balancers. The same NSX Manager is used to configure East-West VNF connectivity, North-South routing, and out-of-band management access for VNFs.
Infrastructure networks are used by the ESXi hypervisor for vMotion, VMware vSphere® Fault Tolerance, and vSAN traffic. The Virtual Machine networks are used by Virtual Machines to communicate with each other. For each pod, the separation between infrastructure and Virtual Machine networks ensures security and provides network resources where needed. This separation is implemented by two distributed switches, one for infrastructure networks and the other for Virtual Machine networks. Each distributed switch has separate uplink connectivity to the physical data center network, completely separating its traffic from other network traffic. The uplinks are mapped to a pair of physical NICs on each ESXi host, for optimal performance and resiliency.
