What type of VPN employs a hub-and-spoke configuration to establish a full mesh topology?

A Dynamic Multipoint VPN (DMVPN) employs a hub-and-spoke configuration to establish a full mesh topology efficiently. In a typical DMVPN setup, the hub acts as the central point through which all spokes communicate, but the unique feature of DMVPN allows spokes to create direct connections with one another, effectively forming a full mesh over the hub.

This means that while the traditional hub-and-spoke model is often used to connect remote sites (spokes) to a central site (hub), DMVPN's ability to dynamically set up direct paths between spokes without having every possible connection pre-configured expands its utility. This dynamic capability not only reduces the complexity of configuration but also optimizes bandwidth utilization and provides resilience in network connectivity.

Other types of VPNs listed do not support this dynamic full mesh capability in the same way. For instance, site-to-site VPNs typically connect remote offices to a central site, but each connection must be manually configured and does not easily support direct spoke-to-spoke traffic. Remote access VPNs primarily enable individual users to connect to a central network rather than facilitating multi-site connections. IPsec VPN refers to a protocol suite used for securing internet protocol communications and can be used in various configurations but does not inherently define the topology