Professional-Cloud-Network-Engineer Exam Dumps : Google Cloud Certified - Professional Cloud Network Engineer

To block traffic based on BGP ASN, you need to use Cloud Armor network edge security policies. Backend security policies protect backend services (like those behind an external HTTP(S) Load Balancer), but for traffic directly to Compute Engine instances with public IPs, you need a network edge security policy. Firewall policies operate at the VPC level and do not have the capability to filter based on BGP ASN. The —network-src-asns parameter is specifically used with Cloud Armor network edge security policies to filter traffic based on the source ASN.

Exact Extract:

"Cloud Armor network edge security policies can protect external IP addresses of virtual machine (VM) instances and load balancers. They support rules that allow or deny traffic based on various criteria, including source autonomous system numbers (ASNs) using the --network-src-asns parameter."

"Network edge security policies are designed for traffic destined for external IP addresses of Google Cloud resources that are not behind an external HTTP(S) load balancer, such as Compute Engine instances with public IP addresses."Reference: Google Cloud Armor Documentation - Network edge security policies overview

The most effective long-term solution to address IPv4 address exhaustion in GKE clusters, while still ensuring routability and unique ranges per cluster, is to transition to dual-stack IPv4/IPv6 clusters and leverage IPv6 for Pods and Services. This allows you to conserve IPv4 addresses for critical use cases while providing a vast address space with IPv6 for pods and services, significantly reducing the pressure on your private IPv4 ranges. Google Cloud GKE fully supports dual-stack networking.

Exact Extract:

"Dual-stack clusters enable you to assign both IPv4 and IPv6 addresses to Pods and Services. This approach helps conserve IPv4 address space by shifting a significant portion of the network communication to IPv6, particularly for internal cluster communication or communication with other IPv6-enabled services."

"When you enable dual-stack networking, GKE assigns an IPv6 address range to your Pods and can also assign IPv6 addresses to Services. This significantly expands the available addressing capacity within your cluster."Reference: Google Kubernetes Engine Documentation - Dual-stack networking