Hybrid Cloud Networking: Challenges, Architecture & Best Practices

Hybrid cloud networking focuses on connecting on-premises infrastructure to cloud environments, but it tends to receive less attention than the broader hybrid infrastructure management conversation. The connectivity layer poses genuine technical challenges that management practices do not fully address. The connection between environments is often treated as a one-time setup task, neglecting its ongoing architectural concerns and performance implications as both environments evolve independently.

When connecting on-premises infrastructure to the cloud, organizations face a choice between site-to-site VPNs over the public internet and dedicated connections like AWS Direct Connect, Azure ExpressRoute, or Google Cloud Interconnect. VPNs are faster and cheaper but offer variable performance dependent on internet conditions. Dedicated connections provide predictable performance and better security but come at a higher cost with longer setup lead times.

Organizations should evaluate the right choice based on the specific workloads rather than defaulting to always use the more expensive or cheaper option. For latency-sensitive or high-volume workloads, a dedicated connection may justify its cost. Conversely, lower-stakes, lower-volume connectivity might suffice with a VPN.

Routing between environments requires deliberate design rather than relying on default assumptions. Traffic should be routed to stay within its respective environment rather than crossing the hybrid connection unnecessarily, which adds latency and connection cost without providing genuine benefits. Workloads should be reviewed periodically to ensure they are not needlessly crossing the hybrid boundary.

DNS resolution must be consistent across both environments to avoid confusion and misdiagnosed failures. A hybrid DNS architecture with consistent resolution, regardless of the request's origin, is necessary. This should be explicitly tested rather than assumed correct once configured.

Lastly, security policies must be consistently applied across the hybrid boundary. Security treatment should remain rigorous whether traffic is flowing from on-premises to cloud or vice versa. This consistency is often overlooked, as on-premises security policy has evolved through years of review and refinement, while the cloud environment has not yet undergone the same iterative hardening process. Recognizing this structural risk and implementing ongoing reviews is crucial to maintaining strong security practices.