Deploying DSVPN in Hierarchical Hub Networking
Figure 1 shows a network topology of an enterprise. The organizations of the enterprise are hierarchical. DSVPN is deployed on the network. Some intermediate nodes function as both the Spokes and Hubs. For example, Hub1 and Hub2 function as Hubs for its downstream Spokes and serve as Spokes for the Hub in the headquarters.
The principles of establishing dynamic mGRE tunnels between Spokes of Hub1 and Hub2 are similar to Principles. When a Spoke of Hub1 needs to establish a dynamic mGRE tunnel with a Spoke of Hub2, the source Spoke sends an NHRP Resolution Request packet to Hub1. Hub1 sends the NHRP Resolution Request packet to the Hub, the Hub sends the NHRP Resolution Request packet to Hub2, and Hub2 sends the NHRP Resolution Request packet to the destination Spoke. Finally, a dynamic mGRE tunnel is set up between Spokes in hierarchical Hub networking.
When DSVPN is deployed in hierarchical Hub networking, branches can learn routes from each other in shortcut mode only.
