To build an SD-WAN overlay network without the need to statically build SD-WAN overlay route tables:
1. Create a WAN Path tunnel across each WAN link between two SD-WAN appliances.
2. Configure Virtual IP to represent the endpoint for each WAN link. You can establish encrypted WAN paths through the current L3 Network.
3. Aggregate 2, 3, and 4 WAN paths (physical links) into a single Virtual Path allowing packets to traverse the WAN utilizing the SD-WAN overlay network instead of the existing underlay which is least intelligent and cost inefficient.
SD-WAN Routing Components and Network Topology
• Local – subnet resides at this site (advertised to SD-WAN environment)
• Virtual Path – sent through Virtualized Path to the selected site appliance
• Intranet – sites with no SD-WAN appliance
• Internet – internet bound traffic
• Pass-through – untouched traffic, in one bridge interface out the other
• Default route (0.0.0.0/0) defined. Used for pass-through traffic not captured by the SD-WAN overlay route table, or utilized at the MCN to instruct clients sites to forward all traffic back to MCN node for back-haul of internet traffic.