According to the Nutanix Prism Central Guide, role-based access control (RBAC) in Prism Central allows you to create custom roles and assign them to users or groups based on the categories of the entities they need to manage1. Categories are key-value pairs that you can assign to entities such as VMs, hosts, clusters, images, etc. to group them logically2. For example, you can create a category key called "OS" and assign values such as "Linux" or "Windows" to different VMs based on their operating system.
In the exhibit, the Linux Admin role has been created with the following settings:
* The role has the "VM Admin" permission, which allows the user to perform all actions on VMs3.
* The role has been assigned to the admin1 user.
* The role has been scoped to the entities that have the category key "OS" and the value "Linux".
However, the admin1 user does not have access to all Linux VMs in the environment. This means that some of the Linux VMs do not have the proper category assigned to them. To grant the proper access, the administrator should add the category key "OS" and the value "Linux" to each Linux VM that needs to be managed by the Linux Admin role. This can be done either individually or in bulk through Prism Central4. Once the categories are added, the admin1 user will be able to see and manage all Linux VMs in the environment.

According to the Nutanix Support & Insights web search result1, route injection is used to maintain I/O operations in the cluster when the Stargate service becomes unavailable on a single CVM on an AHV node.
Route injection is a mechanism that allows the CVMs to communicate with each other and redirect the I/O requests to another healthy CVM in the cluster. Route injection uses the Linux kernel routing table to add or delete routes dynamically, based on the availability of the Stargate service on each CVM.

Reference:
https://next.nutanix.com/how-it-works-22/scheduled-power-outage-relocating-cluster-hardware-if-you-need-to-shut-down-all-the-nodes-in-your-ahv-cluster-here-s-how-37326

Explanation
http://www.vstellar.com/2019/01/10/ahv-networking-part-1
-basics/#:~:text=AHV%20Network%20Architecture&text=virbr0%20is%20an%20internal%20switch,virbr0)%2