VMware vRealize Network Insight (or commonly called as vRNI), is a product that you would definitely want to have in your Environment, as it delivers intelligent operations for software-defined networking and security.

It basically serves as “One-Stop Solution” for Network management/operations.
Tools traditionally available for this purpose, are inadequate for modern virtual networks as they have limited visibility and control. On the contrary, vRNI can bring in, a lot of intelligent analytics to the Network Data that it collects from the sources. These sources can be your vCenter Server, NSX-v/T Manager, Public Cloud or it can be Firewall, Routers & Switches, Cisco UCS, etc.

Now with this processed data, you would be able to
1. Perform Micro-segmentation Planning
NSX offers segmentation capabilities, however, the challenge is to determine where to apply segments since you would have thousands of VMs with unknown conversation patterns spread across single/multiple clusters. vRNI would help you in this.

2. Optimize Network Performance with 360-degree Visibility & Analytics
This would reduce time to resolve application-connectivity issues, as well as improve application performance by eliminating Network bottlenecks. In addition to that, you can also audit Network & Security changes over time.

3. Ensure best practices, health & availability of NSX Deployments
You can scale across multiple NSX Managers. Also you can enhance uptime by proactively detecting misconfiguration errors like MTU mismatch errors, etc