Which type of VPN connects a central site with branch sites flexibly?

The Cisco Dynamic Multipoint VPN (DMVPN) is designed specifically to connect central sites with multiple branch sites in a flexible and scalable manner. It employs a hub-and-spoke topology, where the hub acts as the central point of communication. One of the key features of DMVPN is its ability to dynamically create secure tunnels between branch sites without requiring a static tunnel configuration between all branches and the central site. This is particularly beneficial when there are many branch offices that need to establish connections with one another as well.

DMVPN utilizes protocols like Next Hop Resolution Protocol (NHRP) and supports various encryption protocols, including IPsec, to ensure data security. This configuration reduces the complexity involved in managing multiple static VPN connections, allowing branches to communicate directly with each other as required. It can also adapt to changes in the network topology efficiently, which is advantageous for organizations with fluctuating site connectivity needs.

In contrast, while site-to-site VPNs provide secure connections between two fixed locations, they do not offer the same level of dynamic connectivity as DMVPN. An IPsec VPN is more about the encryption method rather than the dynamic topology aspect. SSL VPNs are typically better suited for secure remote access by individual users instead of being used to connect multiple sites.