For Network Connectivity Center to properly enable site-to-site data transfer, you must configure spoke resources in high availability configurations. If you don't, sites might be unable to pass traffic to one another.
Each resource type has different requirements for high availability, as described in the following sections.
High availability for Cloud Interconnect
For site-to-site data transfer to work correctly with Cloud Interconnect resources, you must configure multiple Interconnect connections, each in a separate edge availability domain.
For detailed information about how to configure Cloud Interconnect resources for high availability, see the following documentation:
- Redundancy and SLA for Dedicated Interconnect
- Establishing 99.99% availability for Dedicated Interconnect
- Redundancy and SLA for Partner Interconnect
- Establishing 99.99% availability for Partner Interconnect
- Creating redundant Interconnect connections with sufficient capacity
High availability for Cloud VPN
For site-to-site data transfer to work correctly with Cloud VPN resources, you must configure multiple HA VPN gateway interfaces and tunnels to achieve a 99.99% SLO. For guidance, see the Cloud VPN overview.
High availability for Router appliance
For site-to-site data transfer to work correctly with router appliance instances attached to a spoke, you must do the following:
If you place all your router appliance instances in a single spoke, use equal-cost multipath (ECMP) to advertise the same set of prefixes from two router appliance instances. To advertise different prefixes for each spoke, add each router appliance instance to a different spoke.
You can't create a cross-region configuration in a single spoke.
ECMP is the result of advertising the same prefix or prefixes, with the same MEDs and AS path as applicable, from two or more router appliance instances. The guidance about route selection in VPC networks applies to router appliance instances as it does to other Google Cloud resources.
For detailed information about how to configure router appliance instances for high availability, see requirements for 99.9% availability.
What's next
- To view a sample topology, see Sample topology for site-to-site data transfer.
- To learn more about how Network Connectivity Center enables full mesh connectivity, see Route exchange with site-to-site data transfer.
- To work through a tutorial, see Connecting two sites by using Cloud VPN spokes.
- To create hubs and spokes, see Working with hubs and spokes.
- To view a list of partners whose solutions are integrated with Network Connectivity Center, see Network Connectivity Center partners.