VMware NSX is a platform for the virtualization and security organization of network services. NSX helps configure routing, distribute loads, manage firewalls, and perform other tasks that system administrators constantly face.
Here’s a common situation: the firewall configuration becomes a long list of addresses, ports, subnets, and protocols. At first, the system administrator keeps order and follows logical structure—perhaps even leaves comments for colleagues and successors. But over time, disorder grows.
Employees change, the administrator leaves, and the configuration becomes impossible to modify without risking the entire system. Each day, the tangle gets more and more complicated.
To reduce such situations, VMware once introduced CNS vShield Edge. It was a separate virtual machine that worked as a boundary gateway. The administrator could configure most network functions there. Firewall and NAT rules were used to limit interaction with external networks.
If one really wanted to separate traffic, it was possible to create a separate network for different VMs and write network interaction rules in the firewall. But that was not a pleasant task—especially if the infrastructure consisted of several dozen VMs.
VMware NSX replaced CNS vShield Edge. Its main feature is a distributed firewall built into the hypervisor. In it, you can define interaction policies for any object: IP, MAC, virtual machine, application, or device connected via VMware PCI. Each object gets its own security perimeter, which can be flexibly configured.
We already briefly mentioned one capability—network microsegmentation. It is implemented through the distributed firewall. This feature allows for precise control of security policies for VMs and applications.
Thanks to microsegmentation, you don’t bombard the entire system with broad restrictions. It also reduces the risk of lateral (horizontal) threat propagation within the data center. One compromised segment is not a death sentence.
Another useful feature is the easy movement of network objects. For example, you can take a VM with data and move it to another segment or even another virtual data center. The rules for that VM will continue to apply regardless of its new location. The physical network topology also doesn’t matter; the only requirement is that communication with the previous virtual data center remains.
By removing network and security tool limitations, the virtual environment is no longer tied to physical hardware. This increases resource utilization efficiency and significantly speeds up network initialization.
The VMware NSX platform consists of several components:
Controller Cluster: a system made up of physical or virtual machines (at least three). It is designed for deploying virtual networks. All machines work in high-availability mode and receive commands through an API. The cluster manages vSwitches and Gateways, which implement virtual networks. Essentially, the Controller Cluster defines network topology, analyzes traffic, and determines how to configure network components.
NSX Manager: a tool that helps manage virtual networks through a web console. It interacts with the Controller Cluster.
Hypervisor vSwitches: virtual switches that handle virtual machine traffic.
Gateways: components that connect virtual and physical networks.
Ecosystem Partners: components through which partners can integrate their virtual modules.
The server hypervisors in an NSX system can be VMware vSphere, KVM, or Xen.
The NSX network virtualization platform allows implementation of the Zero Trust Security model. It is effective for defending against attacks targeting the least protected parts of the system. The core principles of this concept are:
VMWare’s application virtualization helps create security segments for individual objects, implementing the principles of zero trust. This ensures the entire system has a high level of protection against unauthorized access.
VMWare NSX virtualization is applied to solve various tasks. Let’s look at a few common scenarios.
The most logical use case is dividing a data center into many security segments, each with its own rules. The configuration does not depend on the environment in which the segment operates and is based on user and application behavior scenarios.
Microsegmentation helps network administrators instantly detect threats and begin neutralizing them. This approach also greatly reduces the risk of lateral threat spread—the key distinction between NSX and traditional networks. Even if an attacker breaches the perimeter defense, they cannot move laterally within the data center.
To ensure security and control over interactions, NSX provides a wide range of tools:
Additionally, VMware Mail can be configured to receive instant notifications about operational issues.
Before NSX, network initialization was done manually; it required a lot of time and resources and often led to errors. NSX eliminates these issues completely. Networks are created programmatically, removing bottlenecks tied to physical infrastructure.
By virtualizing network and security services, application lifecycle management can also be automated. Developers can offload routine deployment and maintenance operations, freeing time for other tasks, such as reducing technical debt or implementing new business features.
The VMware NSX concept separates the network from physical hardware. Security policies are bound to specific workloads, allowing services and applications to be migrated between data centers in minutes.
Data can be replicated to remote sites, and applications can be deployed without interacting with the physical layer—all without any downtime, not even for a moment.