Hello Victor
When you use DMVPN with NHRP in the configuration found in the lesson, on each spoke you use the following command:
ip nhrp map <tunnel address> <hub NBMA address>
This creates a static peer address, and that’s why you see the “S” indicator on the spoke router. This is considered a statically configured NBMA peer address.
On the hub, however, you have no such configuration. The hub is configured to accept NHRP requests to dynamically add the addresses of the spokes. For this reason, on the Hub, you will see the “D” designation that these are dynamically learned addresses.
You can, however, configure static spoke addresses on the hub if you like, but this defeats the purpose of the simplicity of implementation and the scalability of DMVPN.
I hope this has been helpful!
Laz
I hope this has been helpful!