I'm in a process of designing a DMVPN solution with 3 hubs and 40-50 Spokes.
Each HUB (Primary Centre, DR Centre & Head Office) has two routers each.
Spoke routers are not expected to talk to each other. Only communication allowed is with the 3 Hub Location networks.
Hence i would have to deploy DMVPN Hub/Spoke topology.
I have gone thru the DMVPN Design Guide : SRND: April 2005.
It suggests that in Hub-Spoke DMVPN Topology, Create different DMVPN Groups for each Hub location Router with mGRE Configuration, and deploy Plain Vanilla GRE at Spoke Locations.
Using this philosophy. As i have 6 Hub Routers (2 HUB Location x 2 Routers). I would end up with
6 DMVPN Groups in the Network
single mGRE Tunnel at a Hub Router
6 GRE Tunnels at Spoke Locations.
Is there a better way to implement this topology, or this design would be ok.
Also FYKI, i would be implementing OSPF as the Routing Protocol within GRE Tunnels.
Kindly address any issues/optimizations in the above design.