You need private VMs in a subnet to access the internet without assigning external IPs. Does Cloud NAT require a Cloud Router to provide NAT for these VMs?

Cloud NAT operates independently of Cloud Router for its primary function of providing NAT for private VMs. Cloud Router is primarily used for establishing BGP peering connections for VPNs (like HA VPN) and Cloud Interconnect, and for dynamic routing. While Cloud NAT can be configured to use a Cloud Router for specific advanced scenarios (e.g., when the NAT gateway is in a different region than the VMs and needs to route traffic through a Cloud Router), it is not a general requirement for basic internet egress for private VMs. The other options are incorrect because Cloud NAT does not inherently require a Cloud Router for its core functionality, nor is its dependency limited to HA VPN or IPv6.