DMVPN spokes can use either point-to-point GRE tunnels or multipoint GRE tunnel interface. Recently, I received a question regarding DMVPN.
In fact, the Reader asked me two questions: When is GRE used in network design? When is mGRE used in network design?
Answering the aforementioned questions are the basics that you must know if you are planning to design DMVPN network.