Network Connectivity Center topologies

This page describes the high-level Network Connectivity Center topology and two possible topologies for Router appliance.

Network Connectivity Center topology

Network Connectivity Center supports the following types of Network Connectivity Center resources attached to spokes. It also supports data transfer between on-premises branch offices and data center facilities.

For detailed information, see the Network Connectivity Center overview and Route exchange.

Network Connectivity Center concept.
Network Connectivity Center concept (click to enlarge)

Router appliance spoke topologies

The following sections show site-to-site and single-site topologies for Router appliance spokes.

Site-to-site topology

You can use Router appliance to enable data transfer between environments outside of Google Cloud—for example, between your on-premises branch offices or stores.

The following example topology shows two on-premises sites that use Router appliance spokes to communicate with each other by using a Network Connectivity Center hub.

Router appliance topology
Router appliance topology (click to enlarge)
  1. On-premises Customer network A and Customer network B are each connected through customer premises equipment (CPE) to a router appliance instance. CPEs typically use a connectivity mechanism, such as an SD-WAN overlay tunnel or an IPsec VPN tunnel, to establish connectivity with the router appliance instance.

    Each router appliance instance is located in the Google Cloud region closest to its associated customer network. Both router appliance instances are in a single VPC network; however, because the router appliance instances sit in different regions, the VPC network has its dynamic routing mode set to global.

    You can create router appliance instances only in locations where Network Connectivity Center is supported. For more information, see the Network Connectivity Center locations page.

  2. Both router appliance instances are attached as spokes to the Network Connectivity Center hub.

  3. Each router appliance instance establishes BGP peering with the Cloud Router in the router appliance instance's respective region. The Cloud Router receives and advertises route prefixes from the on-premises location.

  4. The Cloud Routers in both regions dynamically exchange all received routes with each other. This configuration provides end-to-end dynamic route exchange and data plane connectivity between Customer network A and Customer network B.

Single-site topology using load balanced router appliance instances

The following topology shows load balanced router appliance instances to a single on-premises site.

For a detailed description of this topology, BGP route exchange, and step-by-step instructions about how to configure it, see Creating router appliance instances.

Creating BGP sessions for router appliance instances.
Creating BGP sessions for router appliance instances (click to enlarge)

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