According to the Nutanix Support & Insights web search result3, shadow clones are vDisk copies that are created by the cluster when a vDisk is read by multiple VMs. Shadow clones are immutable copies of a vDisk that are stored in different nodes in the cluster, and are used to improve read performance and reduce network traffic. Shadow clones are automatically created and deleted by the cluster, based on the demand and availability of resources.

when you create a new virtual switch on AHV, you need to select one or more uplink interfaces that are connected to a physical network. You cannot select an interface that is already assigned to another virtual switch. By default, AHV creates a virtual switch called br0 that uses all available interfaces on the host2. Therefore, if you want to use some of those interfaces for another virtual switch, you need to remove them from br0 first.
https://masteringnutanix.com/2020/06/13/how-to-create-an-ahv-virtual-switch-with-single-uplink/

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.