The NSX components work together to provide the following functional services.

Logical Switches

A cloud deployment or a virtual data center has a variety of applications across multiple tenants. These applications and tenants require isolation from each other for security, fault isolation, and non-overlapping IP addresses. NSX allows the creation of multiple logical switches, each of which is a single logical broadcast domain. An application or tenant virtual machine can be logically wired to a logical switch. This allows for flexibility and speed of deployment while still providing all the characteristics of a physical network's broadcast domains (VLANs) without physical Layer 2 sprawl or spanning tree issues.

A logical switch is distributed and can span across all hosts in vCenter (or across all hosts in a cross-vCenter NSX environment). This allows for virtual machine mobility (vMotion) within the data center without limitations of the physical Layer 2 (VLAN) boundary. The physical infrastructure is not constrained by MAC/FIB table limits, because the logical switch contains the broadcast domain in software.

Logical Routers

Routing provides the necessary forwarding information between Layer 2 broadcast domains, thereby allowing you to decrease the size of Layer 2 broadcast domains and improve network efficiency and scale. NSX extends this intelligence to where the workloads reside for East-West routing. This allows more direct VM-to-VM communication without the costly or timely need to extend hops. At the same time, NSX logical routers provide North-South connectivity, thereby enabling tenants to access public networks.

Logical Firewall

Logical Firewall provides security mechanisms for dynamic virtual data centers. The Distributed Firewall component of Logical Firewall allows you to segment virtual datacenter entities like virtual machines based on VM names and attributes, user identity, vCenter objects like datacenters, and hosts, as well as traditional networking attributes like IP addresses, VLANs, and so on. The Edge Firewall component helps you meet key perimeter security requirements, such as building DMZs based on IP/VLAN constructs, and tenant-to-tenant isolation in multi-tenant virtual data centers.

The Flow Monitoring feature displays network activity between virtual machines at the application protocol level. You can use this information to audit network traffic, define and refine firewall policies, and identify threats to your network.

Logical Virtual Private Networks (VPNs)

SSL VPN-Plus allows remote users to access private corporate applications. IPsec VPN offers site-to-site connectivity between an NSX Edge instance and remote sites with NSX or with hardware routers/VPN gateways from 3rd-party vendors. L2 VPN allows you to extend your datacenter by allowing virtual machines to retain network connectivity while retaining the same IP address across geographical boundaries.

Logical Load Balancer

The NSX Edge load balancer distributes client connections directed at a single virtual IP address (VIP) across multiple destinations configured as members of a load balancing pool. It distributes incoming service requests evenly among multiple servers in such a way that the load distribution is transparent to users. Load balancing thus helps in achieving optimal resource utilization, maximizing throughput, minimizing response time, and avoiding overload.

Service Composer

Service Composer helps you provision and assign network and security services to applications in a virtual infrastructure. You map these services to a security group, and the services are applied to the virtual machines in the security group using a Security Policy.

NSX Extensibility

3rd-party solution providers can integrate their solutions with the NSX platform, thus enabling customers to have an integrated experience across VMware products and partner solutions. Data center operators can provision complex, multi-tier virtual networks in seconds, independent of the underlying network topology or components.