Shared VPC and VPC Peering

Shared VPC

Allows an organization to connect resources from multiple projects to a common VPC network
Allows the resources to communicate using internal IPs from the shared network

Allows private connectivity across VPC networks regardless if they belong to the same project or same organization
Each VPC network may have its own firewall rules
In order for VPC peering to be established the producer network admin needs to peer the producer network with the consumer network and vice-versa
When both peering connections are created, the peering session becomes active and routes are exchanged