Dedicated Interconnect provides direct physical connections between your on-premises network and Google's network. Dedicated Interconnect enables you to transfer large amounts of data between networks, which can be more cost-effective than purchasing additional bandwidth over the public internet.
Before you use Dedicated Interconnect
Ensure that you meet the following requirements:
- Be familiar with basic network interconnections so that you can order and configure circuits.
- Be familiar with Cloud Interconnect terminology.
- Your network must physically meet Google's network in a colocation facility. You must provide your own routing equipment. Your on-premises router is typically located in the colocation facility. However, you can also extend your connection to a router outside of the colocation facility.
In the colocation facility, your network devices must support the following technical requirements:
10-Gbps circuits, single mode fiber, 10GBASE-LR (1310 nm), or 100-Gbps circuits, single mode fiber, 100GBASE-LR4
IPv4 link local addressing
LACP, even if you're using a single circuit
EBGP-4 with multi-hop
How does Dedicated Interconnect work?
For Dedicated Interconnect, you provision a Dedicated Interconnect connection between the Google network and your own network. The following example diagram shows a single Dedicated Interconnect connection between a Virtual Private Cloud (VPC) network and your on-premises network.
For the basic setup shown in the diagram, a Dedicated Interconnect connection is provisioned between the Google network and the on-premises router in a common colocation facility. Your setup might be different if your on-premises router is not in the same colocation facility as your Dedicated Interconnect demarcation.
When you create a VLAN attachment, you associate it with a Cloud Router. This Cloud Router creates a BGP session for the VLAN attachment and its corresponding on-premises peer router. The Cloud Router receives the routes that your on-premises router advertises. These routes are added as custom dynamic routes in your VPC network. The Cloud Router also advertises routes for Google Cloud resources to the on-premises peer router.
You have the option of specifying dual-stack IPv4 and IPv6 as a stack type when you create or update a VLAN attachment for Dedicated Interconnect. Configuring your attachment to be dual-stack allows you to exchange IPv6 addresses between your on-premises network and your VPC network.
To enable IPv6 traffic exchange in Dedicated Interconnect, you must also enable IPv6 prefix exchange in the IPv4 BGP sessions that are configured on the associated Cloud Router. Your IPv6-enabled VPC networks must include dual-stack subnets. In addition, the subnets must be assigned internal IPv6 ranges.
You must also configure IPv6 addresses on the VMs in the subnet.
- To create a custom mode VPC network with internal IPv6 addresses, see Create a custom mode VPC network with at least one dual stack subnet.
- To create a subnet with IPv6 enabled, see Add a dual-stack subnet.
- To enable IPv6 in an existing subnet, see Convert an IPv4 subnet to a dual stack subnet.
- To create or enable VMs with IPv6, see Configuring IPv6 for instances and instance templates.
For information about using internal IPv6 ranges in your VPC network and subnets, see Internal IPv6 specifications.
To create and configure a Dedicated Interconnect connection, you start by deciding where you want a Dedicated Interconnect connection and whether you want MACsec for Cloud Interconnect. Then, you order a Dedicated Interconnect connection so that Google can allocate the necessary resources and send you a Letter of Authorization and Connecting Facility Assignment (LOA-CFA). After you receive the LOA-CFA, you need to submit it to your vendor so that they can provision the connections between Google's network and your network.
You then need to configure and test the connections with Google before you can use them. After they're ready, you can create VLAN attachments to allocate a VLAN on the connection.
For detailed steps to provision a Dedicated Interconnect connection, see the Provisioning overview.
Redundancy and SLA
Depending on your availability needs, you can configure Dedicated Interconnect to support mission-critical services or applications that can tolerate some downtime. To achieve a specific level of reliability, Google has two prescriptive configurations:
- Establish 99.99% availability for Dedicated Interconnect (recommended)
- Establish 99.9% availability for Dedicated Interconnect
For the highest level availability, we recommend the configuration for
99.99% availability as the base configuration, as shown in the following diagram.
Clients in the on-premises network can reach the IP addresses of virtual
machine (VM) instances in the
us-central1 region through at least one of the
redundant paths. If one path is unavailable, the other paths can continue to
We recommend that you use the 99.99% availability configuration for production-level applications with a low tolerance for downtime. If your applications aren't mission-critical and can tolerate some downtime, you can use the 99.9% availability configuration.
The SLA requires properly configured topologies that are defined by the 99.99% and 99.9% configurations. These configurations ensure availability and provide an SLA.
Balance egress traffic with redundant connections
When you have a redundant topology similar to the 99.99% configuration, there are multiple paths for traffic to traverse from the VPC network to your on-premises network.
Google Cloud uses ECMP to balance the egress traffic across connections. To use ECMP, the Cloud Routers used by the VLAN attachments must receive the same announcement with equal cost (the same CIDR range and the same MED values).
Dedicated Interconnect does the following to balance traffic across connections:
All VLAN attachments operate on Dataplane v1. Traffic is balanced approximately, according to the configured capacity. Traffic balancing might not work optimally when VLAN attachment capacities are different.
All VLAN attachments operate on Dataplane v2. Google Cloud balances the traffic between the VLAN attachments based upon the configured capacity of each VLAN attachment.
VLAN attachments operate on a mix of Dataplane v1 and v2. Egress traffic might be misbalanced between the VLAN attachments. Misbalanced traffic is most noticeable for attachments with under 1 Gpbs of configured capacity.
Google is migrating all existing VLAN attachments to use Dataplane v2 without any action required on your part. If you need to migrate to Dataplane v2 to resolve misbalanced VLAN attachments, contact Google Cloud Support.
Create redundant connections with sufficient capacity
The Best practices document describes best practices for creating redundant Cloud Interconnect connections that have sufficient capacity in a failover scenario. Following these practices helps ensure that events such as planned maintenance or hardware failures do not cause loss of connectivity.
Dedicated Interconnect availability
A Dedicated Interconnect connection is considered available if
you can send and receive packets (ICMP
ping) between a VM in a specific
Google Cloud region and a correctly configured machine in your on-premises
network. You should be able to send and receive packets through at
least one of your redundant connections.
Restrict Dedicated Interconnect usageBy default, any VPC network can use Cloud Interconnect. To control which VPC networks can use Cloud Interconnect, you can set an organization policy. For more information, see Restrict Cloud Interconnect usage.
- To find answers to common questions about Cloud Interconnect architecture and features, see the Cloud Interconnect FAQ.
- To find out more about Cloud Interconnect, see the Cloud Interconnect overview.
- To learn about best practices when planning for and configuring Cloud Interconnect, see Best practices.
- To find Google Cloud resource names, see the Cloud Interconnect APIs.