The NSX data plane consists of the NSX vSwitch, which is based on the vSphere Distributed Switch (VDS) with additional components to enable services. NSX kernel modules, userspace agents, configuration files, and install scripts are packaged in VIBs and run within the hypervisor kernel to provide services such as distributed routing and logical firewall and to enable VXLAN bridging capabilities.
The NSX vSwitch (vDS-based) abstracts the physical network and provides access-level switching in the hypervisor. It is central to network virtualization because it enables logical networks that are independent of physical constructs, such as VLANs. Some of the benefits of the vSwitch are:
Support for overlay networking with protocols (such as VXLAN) and centralized network configuration. Overlay networking enables the following capabilities:
Reduced use of VLAN IDs in the physical network.
Creation of a flexible logical Layer 2 (L2) overlay over existing IP networks on existing physical infrastructure without the need to re-architect any of the data center networks
Provision of communication (east–west and north–south), while maintaining isolation between tenants
Application workloads and virtual machines that are agnostic of the overlay network and operate as if they were connected to a physical L2 network
Facilitates massive scale of hypervisors
Multiple features—such as Port Mirroring, NetFlow/IPFIX, Configuration Backup and Restore, Network Health Check, QoS, and LACP—provide a comprehensive toolkit for traffic management, monitoring, and troubleshooting within a virtual network
The logical routers can provide L2 bridging from the logical networking space (VXLAN) to the physical network (VLAN).
The gateway device is typically an NSX Edge virtual appliance. NSX Edge offers L2, L3, perimeter firewall, load balancing, and other services such as SSL VPN and DHCP.