https://www.cisco.com/c/en/us/support/docs/security-vpn/ipsec-negotiation-ike-protocols/41940- dmvpn.html#dyntun Dynamic Tunnel Creation for "Spoke-to-Hub" Configuration of the hub router is shortened and simplified since it does not need to have any GRE or IPsec information about the peer routers. All of this information is learned dynamically via NHRP. D is wrong box spokes are the devices who initiate the tunnel using NHRP not the HUB