Which function does vSmart perform in the Cisco SD-WAN architecture?

The vSmart controller is the centralized brain of the Cisco SD-WAN overlay network, responsible for establishing, maintaining, and controlling the data plane. A key function it performs is the distribution of IPsec keys and other security parameters to the vEdge routers. This ensures secure communication between vEdge devices by setting up the necessary encryption tunnels. Localized policies are executed by the vEdge routers themselves, not the vSmart controller, as these policies apply to traffic entering or exiting a specific site. Redistribution between OMP (Overlay Management Protocol) and other routing protocols (like OSPF or BGP) is handled by the vEdge routers at the service-side interface, integrating the SD-WAN fabric with the traditional network. NAT detection and traversal are primarily functions of the vBond orchestrator, which helps vEdge routers establish connectivity when they are behind NAT devices.