How to achieve 99.99% SLA for on-premises to GCP VPC connectivity?

PCNE By islever Editorial Last updated

Short answer

D Use HA VPN. Configure one tunnel from each interface of the VPN gateway to connect to the corresponding interfaces on the peer gateway on-premises. Configure one Cloud Router and enable global routing in the VPC.

Question

You are responsible for designing a new connectivity solution between your organization's on-premises data center and your Google Cloud Virtual Private Cloud (VPC) network. Currently, there is no end-to-end connectivity. You must ensure a service level agreement (SLA) of 99.99% availability. What should you do?
  1. Use one Dedicated Interconnect connection in a single metropolitan area. Configure one Cloud Router and enable global routing in the VPC.
  2. Use a Direct Peering connection between your on-premises data center and Google Cloud. Configure Classic VPN with two tunnels and one Cloud Router.
  3. Use two Dedicated Interconnect connections in a single metropolitan area. Configure one Cloud Router and enable global routing in the VPC.
  4. Use HA VPN. Configure one tunnel from each interface of the VPN gateway to connect to the corresponding interfaces on the peer gateway on-premises. Configure one Cloud Router and enable global routing in the VPC. Correct Answer

Key Takeaways

Tests understanding of Google Cloud's SLA documentation for hybrid connectivity, highlighting the common trap that a single Dedicated Interconnect or HA VPN tunnel does not qualify for the 99.99% uptime guarantee without cross-metro or multi-gateway redundancy.

Achieving a 99.99% availability SLA for hybrid cloud connectivity requires strict redundancy across geographically diverse locations and network paths. The community consensus confirms that HA VPN with multi-interface tunnel configuration is the correct approach, as single-link Dedicated Interconnects fail to meet the required SLA thresholds.

Common mistake: Many candidates choose A or C, incorrectly assuming that any Dedicated Interconnect configuration automatically provides a 99.99% SLA. In reality, Google requires at least four connections spread across two distinct metropolitan areas to qualify for this tier.

Expert Analysis

Why the Answer Is Correct

HA VPN is explicitly engineered for high-availability enterprise scenarios. Configuring one tunnel from each interface of the VPN gateway to the corresponding on-premises interfaces creates truly active-active paths across independent network segments. When properly routed through a Cloud Router, this multi-interface design satisfies Google's architectural requirements for a 99.99% SLA.

Why the Other Options Are Wrong

Options A and C propose Dedicated Interconnects confined to a single metropolitan area, which directly violates the geographic diversity mandate for top-tier availability. Option B relies on Direct Peering, which routes public internet traffic rather than establishing a private VPC link, and utilizes legacy Classic VPN technology. Neither alternative provides the necessary path independence or modern failover mechanisms required by the exam scenario.

Community Comment Notes

Comment [1] accurately references Google's official guidance that Dedicated Interconnects must span two separate metropolitan areas to earn the 99.99% rating. Comment [3] initially questions the HA VPN SLA but overlooks that the prompt specifies multi-interface tunneling, which fulfills the redundancy criteria. Comments [2] and [5] demonstrate typical exam behavior where candidates validate the SLA matrix and confidently switch to D.

Official Reference

These links open the official vendor documentation in a new tab.

Exam Strategy

Always cross-reference the requested SLA percentage with Google's official networking SLA matrix before selecting an architecture. If a scenario demands 99.99% uptime for hybrid connectivity, immediately eliminate single-link or single-metro designs and prioritize options that explicitly describe multi-path or multi-zone redundancy.

Community Votes

D
66%
A
17%
C
17%

66% of anonymous learners picked answer D. Votes are pick records left by other test-takers — they are not the verified answer.

Discussion 5 contributions

Compiled from public community threads and reader submissions, lightly edited for clarity. Handles and vote tallies are shown as recorded, and comments reflect the views of individual contributors.

From public community threads 5

  1. desertlotus1211 👍 2
    For Dedicated Interconnects: At least four Dedicated Interconnect connections, two connections in one metropolitan area (metro) and two connections in another metro. Connections that are in the same metro must be placed in different edge availability domains (metro availability zones) to achieve 99.99% availability. For HA VPN: HA VPN to peer VPN gateways Connect an HA VPN gateway to one or two separate peer VPN devices 99.99% HA VPN between two Google Cloud networks Connect two Google Cloud VPC networks in a single region by using an HA VPN gateway in each network 99.99%
  2. [Removed] 👍 2 Answered D
    Due to this, I change answer to D
  3. Lucox 👍 1 Answered C
    Its C D said 2 tunnels but on a single VPN gateway, so its only 99.9%
  4. [Removed] 👍 1 Answered A
    a dedicated interconnect offers 99.99% SLA
  5. gonlafer 👍 2 Answered D
    I guess D

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