Technical highlights

What happens to spoke-to-hub traffic when the destination is only reachable through one of the hubs? This can easily happen if the two hubs are located in two different datacenters, with different workloads hosted behind them. To answer this question, recall that the SD-WAN uses routing information as one of its inputs. By default, SD-WAN members can only be selected when they have a route to the destination. Hence, even if the SD-WAN rule prefers the primary hub, it will be skipped for destinations only reachable through the secondary hub.