VPC Network Peering in Google Cloud Platform enables private connectivity between two Virtual Private Cloud (VPC) networks, allowing resources in different VPCs to communicate using internal IP addresses. This feature is essential for organizations that need to connect workloads across separate pro…VPC Network Peering in Google Cloud Platform enables private connectivity between two Virtual Private Cloud (VPC) networks, allowing resources in different VPCs to communicate using internal IP addresses. This feature is essential for organizations that need to connect workloads across separate projects or organizations while maintaining network isolation and security.
When you establish VPC peering, traffic between the peered networks stays within Google's internal network infrastructure, providing lower latency and higher security compared to routing traffic over the public internet. Each VPC network maintains its own firewall rules, routes, and policies, giving administrators granular control over network traffic.
Key characteristics of VPC Network Peering include:
1. **Non-transitive nature**: If VPC-A peers with VPC-B, and VPC-B peers with VPC-C, VPC-A cannot communicate with VPC-C through VPC-B. Each peering relationship must be established separately.
2. **Subnet IP range requirements**: Peered networks cannot have overlapping IP ranges for their subnets. This requires careful IP address planning before establishing peering connections.
3. **Decentralized approach**: Both VPC network administrators must configure the peering connection from their respective sides for it to become active.
4. **Cross-project and cross-organization support**: Peering works across different projects within the same organization or between different organizations entirely.
5. **No single point of failure**: Peering connections are fully distributed and highly available.
Common use cases include connecting development and production environments, enabling shared services architectures, and facilitating multi-team collaboration while maintaining separate network boundaries.
To implement VPC peering, you create a peering connection in the Google Cloud Console or using gcloud commands, specifying the peer network. The connection becomes active once both sides complete the configuration. Network administrators should review firewall rules to ensure appropriate traffic flow between peered networks after establishing the connection.
VPC Network Peering is a networking feature in Google Cloud Platform that allows two Virtual Private Cloud (VPC) networks to connect and communicate using internal IP addresses. This connection enables resources in different VPC networks to exchange traffic as if they were within the same network, regardless of whether they belong to the same project or different projects.
Why is VPC Network Peering Important?
VPC Network Peering is crucial for several reasons:
• Cost Efficiency: Traffic between peered networks uses internal IP addresses, which means you avoid egress charges that would apply to external traffic.
• Low Latency: Peered connections provide lower latency compared to using external IP addresses or VPN connections because traffic stays within Google's network.
• Security: Traffic between peered VPCs never traverses the public internet, enhancing security posture.
• Organizational Flexibility: Enables different teams, departments, or projects to maintain separate VPC networks while still allowing necessary communication.
• Scalability: Supports large-scale architectures where resources need to be distributed across multiple VPC networks.
How VPC Network Peering Works
VPC Network Peering operates on several key principles:
1. Decentralized Architecture: Each side of a peering connection is set up independently. Both VPC networks must establish the peering connection for it to become active.
2. Non-Transitive: Peering is not transitive. If VPC-A peers with VPC-B, and VPC-B peers with VPC-C, VPC-A cannot communicate with VPC-C through VPC-B. Each pair requires its own peering connection.
3. Subnet IP Range Requirements: Peered VPCs cannot have overlapping subnet IP ranges. This is essential for proper routing.
4. Firewall Rules Still Apply: Even with peering established, firewall rules in each VPC control what traffic is allowed. Peering does not override firewall configurations.
5. Route Exchange: When peering is established, subnet routes are automatically exchanged. Custom routes can optionally be exported or imported.
Setting Up VPC Network Peering
To create a peering connection:
• Navigate to VPC Network in the Google Cloud Console • Select VPC Network Peering • Create a peering connection from VPC-A to VPC-B • Create a reciprocal peering connection from VPC-B to VPC-A • Both connections must be established for the peering to become active
Key Limitations to Remember
• Maximum of 25 peering connections per VPC network (can be increased with quota requests) • Peering works across projects and organizations • Internal DNS resolution across peered networks is not automatic • Each VPC network maintains its own firewall rules
Exam Tips: Answering Questions on VPC Network Peering
Tip 1: Remember Non-Transitivity When exam questions describe scenarios with multiple VPCs, always check if the question implies transitive connectivity. VPC Peering requires explicit connections between each pair of networks.
Tip 2: Watch for Overlapping IP Ranges If a question mentions IP address conflicts or overlapping CIDR ranges between VPCs, peering will not work. Look for answers that address IP range conflicts.
Tip 3: Compare with Other Connectivity Options Know when to choose VPC Peering over alternatives: • Use Shared VPC when you need centralized network administration within an organization • Use Cloud VPN for connections to on-premises networks • Use VPC Peering for connecting separate VPC networks that need internal communication
Tip 4: Firewall Rules are Separate Peering establishes connectivity at the network level, but firewall rules must still permit the traffic. If a question describes peering being established but traffic not flowing, look for firewall rule issues.
Tip 5: Cost Considerations When questions ask about reducing network costs between VPCs, VPC Peering is often the answer because it uses internal IP addresses and avoids egress charges.
Tip 6: Cross-Project and Cross-Organization VPC Peering works across different projects and even different organizations. This is a common scenario in exam questions involving multi-tenant architectures.
Tip 7: Look for Keywords Watch for phrases like internal IP communication, low latency between VPCs, private connectivity, or avoiding public internet as indicators that VPC Peering might be the correct solution.