building IPSec and GRE VPNs in a scalable and dynamic way. DMVPN Features Support for dynamic tunnel creation. Multipoint GRE Tunnel Interface. NHRP (Next Hop Resolution Protocol). One GRE link for the support of multiple GRE tunnels. Simplify the complexities of the configuration. Working of DMVPN works on the concept of Hub and Spoke technology. Hub is the NHRP Server of Hub-Spoke Concept and All the Spokes register with the HUB as their Clients. Spokes build a dynamic GRE tunnel with the hub only but not to the other spokes. When the packet has to be sent from one of the spoke to the other spoke. Spoke sends a packet to the private subnet behind another spoke. It gets the response from the NHRP Server (Hub) for the outside address of the destination spoke and then It creates a dynamic IPsec/GRE tunnel to the destination spoke and initiates the tunnel with the peer outside address. Now the dynamic spoke to spoke tunnel is built over mGRE (Multipoint Generic Routing Encapsulation Tunnel). This tunnel is entirely removed when the communication stop happening between the spokes. Downloaded 4/15/2022 9:44:49 AM Nova Southeastern University IP Address: 137.52.76.29 SDN Practical Orientation PFR (PERFORMANCE ROUTING) There are lots of WAN challenges in today's WAN environment: Reliability of the available WAN links. Troubleshooting is getting more and more complex day by day. Lack of visibility into the entire Network Infrastructure and application level visibility. Bandwidth management. Degraded performance. PFR can measure and select the best available path as per real time user defined policies and application level visibility into the network. It gives additional visibility into the traditional routing in addition to path selection. It helps PFR to identify the best path and selecting the best path and make routing adjustment by analyzing the real time performance metrics. Traffic load-balancing across different links by utilizing different link differently is one of the greatest feature of performance Routing PF