I’m not sure that I fully understand what you are trying to achieve, can you provide a diagram?   Fundamentally the iBGP within the SD-WAN only passes routes within the SD-WAN, as the SD-WAN is an Autonomous System. The routes passed to your hub from the SD-WAN will be via eBGP since the hub will be a separate Autonomous System, your MPLS network to your data centre will likely be another Autonomous System, as will the data centre itself. You may be able to manipulate the ASPATH attribute on your hub BGP router, but I can’t see how you intend to use the SD-WAN. ... View more