Network pairs for recovering virtual machines to Google Cloud Platform (GCP)

You need to consider the below mentioned points before creating network pairs for recovering or migrating virtual machines to GCP :

You can only configure a network interface when you create an instance.
You cannot delete a network interface without deleting the instance.
Each network interface configured in a single instance must be attached to a different VPC network, and each interface must belong to a subnet whose IP range does not overlap with the subnets of any other interfaces. The attached network can be a standalone VPC network or a Shared VPC network.
For a workload multiple subnets having single VPC cannot be provisioned on GCP.
For a workload multiple NICs in same subnet cannot be provisioned on GCP
For shared subnets discovery, the host project name is appended to the VPC name to distinguish the shared subnets from the another project.

Figure: Overview of network structure for recovery to Google Cloud Platform

Table: Network Mapping types for Google Cloud Platform

Virtualization technology	Cloud environment	Network Mapping Type	Mandatory	Purpose
VMware	Google Cloud Platform	Subnet to Cloud Subnet	Yes	To connect the VNIC of the recovered virtual machine to the cloud network.
Hyper-V	Google Cloud Platform	Subnet to Cloud Subnet	Yes	To connect the VNIC of the recovered virtual machine to the cloud network.