NSX is VMware's software-defined networking platform, and it comes in two distinct flavors: NSX-V for vSphere environments, and NSX-T for non-vSphere environments. In the NSX-T vs. NSX-V debate, you must take the use cases of each into consideration.
NSX functions as a software version of a network hypervisor; it automates networking and provides multiple network services, such as IP address management. NSX enables organizations to troubleshoot security, automation and networking in the data center. Both versions of the product give you virtual control over switches, routers, access control and firewalls.
The difference between NSX-T vs. NSX-V
VMware built NSX-T and NSX-V on completely different code bases to cater to two different use cases.
NSX-V is the original version of NSX. It's optimized for vSphere environments and offers more features than NSX-T. NSX-V uses a Virtual Extensible LAN (VXLAN) rather than a simple virtual LAN for encapsulation. With a VXLAN, you have more space for traffic, and you can create logical networks to span your entire infrastructure.
NSX-T integrates with more environments than NSX-V, including bare-metal servers, container platforms and all major public clouds, such as AWS and Microsoft Azure. NSX-T uses Generic Network Virtualization Encapsulation (GENEVE). GENEVE is a newer system that defines an encapsulation data format only and doesn't include any control plane specifications.
NSX-V for vSphere
VMware released NSX-V in 2012 after it acquired Nicira. VMware incorporated Nicira Network Virtualization Platform with its own vCloud Networking and Security.
NSX-V is designed to extend the capabilities of vSphere. It requires a vCenter Server and ESXi hosts. NSX-V supports more data center infrastructure products than NSX-T, including Horizon and various third-party storage platforms. It also supports Secure Sockets Layer terminate mode, proxy mode and the addition of HAproxy application rules to a load balancer, and it integrates with different traffic inspection services.
In 2016, when VMware retired a different version of NSX called NSX-MH and introduced NSX-T, NSX-V accounted for more than 90% of NSX sales.
NSX-T for the data center at large
With the work that VMware has put into the platform, NSX-T has nearly -- although not quite fully -- reached feature parity with its cousin, NSX-V.
Not only does NSX-T provide software-defined networking (SDN) services for non-vSphere infrastructures -- such as bare metal, Kubernetes, RHEL and various public clouds -- it integrates with an entire data center's infrastructure, including infrastructure as a service. It provides micro-segmentation, multi-cloud networking, network automation and cloud-native application tools.
Organizations can also implement NSX-T in a variety of endpoints outside the data center, such as remote offices, branch offices and the cloud. NSX-T has IP Address Management capabilities and Container Networking Interface compatibility.
Updates to NSX-T
VMware released NSX-T 2.4 in February 2019, and it includes improvements such as a simplified user interface, Ansible modules and a new API model. Since NSX-T's initial release, VMware has focused on strengthening it for hybrid and multi-cloud environments. If you use NSX Cloud with NSX-T, you can use a single management console for networking and security across your cloud system.
In the past, it seemed as though VMware might attempt to merge the code bases of NSX-T and NSX-V into a single product. Instead, VMware now aims to convince NSX-V users to migrate to NSX-T for the cloud and, in the process, make NSX-T its primary SDN software.
NSX-T vs. NSX-V: The verdict
If all you need is network virtualization for extant applications, NSX-V might be the best choice. Its tight integration with vSphere and its increased number of features make NSX-V a boon, provided you don't require modern applications.
NSX-T is the only version of NSX that supports containers, cloud deployments and modern app development. If you require SDN for any of these, it renders the question of NSX-T vs. NSX-V moot: The answer is NSX-T.
NSX-V might have a head start over NSX-T, but NSX-T's broader reach makes it more appealing to organizations, especially as cloud ecosystems and containerization grow increasingly popular.