Cloud Interconnect

What is Cloud Interconnect?

Cloud Interconnect is Google Cloud’s service for a dedicated, private network connection between your on-premises infrastructure and Google Cloud, bypassing the public internet. It’s the GCP counterpart to AWS Direct Connect and Azure ExpressRoute — a private circuit that provides consistent high bandwidth, predictable low latency, and improved security versus connecting over an internet-based VPN. For organizations moving significant data between on-prem and GCP, running latency-sensitive hybrid workloads, or needing traffic to stay off the public internet for compliance, Cloud Interconnect is the enterprise connectivity option.

The two flavors — Dedicated vs Partner

Cloud Interconnect comes in two forms, and the distinction is the practically useful thing to know. Dedicated Interconnect provides a direct physical connection between your network and Google’s network at a Google colocation facility — you (or your provider) run a physical cross-connect where Google has a presence. It offers high bandwidth (10 Gbps or 100 Gbps circuits, bundled for more) and is the choice when you need large capacity and can meet Google at a colocation point. Partner Interconnect provides connectivity through a supported service provider rather than requiring you to be present at a Google colocation facility — the partner already has the connection to Google, and you connect to the partner. This is the option when you can’t reach a Google colocation facility directly (no presence there) or need lower bandwidth than a full dedicated circuit (Partner offers a range of smaller capacities). So the rule of thumb: Dedicated for high bandwidth when you can physically meet Google at a colo; Partner for smaller bandwidth or when you need a provider to bridge you to Google. Both connect to your GCP VPC via a Cloud Router using BGP for dynamic routing. (Google also offers Cross-Cloud Interconnect for private links to other clouds, and Direct/Carrier Peering for optimized access to Google public services — related but distinct from the private VPC connectivity Cloud Interconnect provides.)

The realities — same tradeoffs as its peers

Cloud Interconnect shares the tradeoffs of all dedicated cloud connections, and the honest guidance is consistent across the three clouds. It’s more expensive and slower to provision than a VPN — a Dedicated Interconnect involves physical cross-connects at a colo (port fees, lead time) and Partner Interconnect involves a provider relationship — so it’s justified by genuine needs for consistent bandwidth, predictable low latency, or a private path for compliance, not for modest or bursty connectivity where GCP’s Cloud VPN (its internet-based IPsec option) is cheaper and far quicker to set up. Redundancy is essential: a single interconnect is a single point of failure, so production-grade deployments use redundant connections (Google’s higher SLA tiers require redundant configurations across separate edge availability domains) and often keep Cloud VPN as a backup path — relying on one circuit risks severing all private connectivity if it fails. And, as always, the decision is need-driven: use Cloud Interconnect when the public internet genuinely isn’t adequate, and Cloud VPN when its lower cost and instant provisioning suffice. This whole toolkit (Dedicated/Partner Interconnect + Cloud Router + VPC) is GCP’s hybrid-cloud networking foundation. The recurring mistakes: reaching for Interconnect (with its cost and lead time) where a VPN would do, deploying a single non-redundant connection (making a single point of failure of your hybrid link), and picking the wrong flavor (Dedicated when you can’t actually meet Google at a colo, or Partner when you need bandwidth beyond what it offers).

What people get wrong

• Using it where Cloud VPN suffices — the dedicated circuit’s cost and provisioning lead time are warranted only by real needs for consistent bandwidth/latency or a private compliance path; VPN is cheaper and instant otherwise.
• No redundancy: a single interconnect is a single point of failure (higher SLAs require redundant connections across edge availability domains) — critical links need redundancy and often a VPN backup.
• Choosing the wrong flavor — Dedicated requires meeting Google at a colocation facility and suits high bandwidth; Partner bridges you via a provider for lower bandwidth or no colo presence; mismatching them causes rework.

Primary source: Google Cloud Interconnect documentation