Default route through underlay

If the RIA functionality is not required, it is enough to keep the default route through the "underlay" zone only:

• Spoke-to-Internet traffic can breakout locally, using this default route.
• Spoke-to-Hub and Spoke-to-Spoke traffic will use the specific routes learned through BGP.

No other routing configuration is needed.

Note, however, that if any other destination exists that must be reached through the overlays (either Internet destination or a legacy site outside the SD-WAN solution), you must ensure that a valid route to that destination through the required overlay exists. This route can be either learned dynamically or configured statically.