Enterprise Hubs Overview

An enterprise hub is an SD-WAN site that is used to carry site-to-site traffic between branch sites and to break out backhaul (central breakout) traffic from branch sites. An enterprise hub typically has a data center department behind it; however, this is not enforced in Contrail Service Orchestration (CSO). You add a enterprise hub from the Sites page.

You can add one or more enterprise hubs to act as central breakout (backhaul) nodes and then associate enterprise hubs with branch sites. The enterprise hub that is associated with a spoke site functions like a data hub and performs the following functions:

• Before the creation of site-to-site tunnels, site-to-site traffic to or from a spoke site is sent through the enterprise hub. This traffic triggers the creation of the site-to-site tunnel based on dynamic mesh thresholds and matching mesh tags that you configure for the spoke site.

• If Internet-bound traffic from the spoke site (and all departments associated with the spoke site) is destined for central breakout (backhaul), the traffic first reaches the assigned enterprise hub and then breaks out from the enterprise hub.

• If a provider hub is associated with the spoke site, the provider hub works as a fallback option in case traffic cannot be sent through the enterprise hub.

If a tenant has more than one enterprise hub configured, CSO statically meshes these sites with overlay tunnels so that the enterprise hubs can exchange routing information for the branch sites with which they are associated. This enables the site-to-site communication between the spoke sites that are associated with different enterprise hubs.

The creation of static tunnels between one enterprise hub and another and between a enterprise hub and a spoke site depends on matching mesh tags. These static tunnels are created during the Zero Touch Provisioning (ZTP) workflow. For more information about mesh tags, see Mesh Tags Overview.

Enterprise hubs can have their own departments similar to other sites. If an enterprise hub does not have directly connected LAN segments in the departments used by the associated spoke sites, then CSO automatically pushes the appropriate department virtual routing and forwarding (VRF) instances to the enterprise hub for connectivity.