Which protocol does Cisco SD-WAN use to protect control plane communication?

STUN is a protocol used for NAT traversal to assist devices in discovering their public IP address and port mappings, not for securing control plane communication in Cisco SD-WAN.

OMP (Overlay Management Protocol) is a routing protocol within Cisco SD-WAN that exchanges routing, policy, and service information, but it relies on the underlying secure DTLS tunnels for its protection, rather than providing the security itself.

IPsec is used by Cisco SD-WAN to secure the data plane communication between vEdge routers, encrypting user traffic, not for protecting the control plane communication.

DTLS (Datagram Transport Layer Security) is the primary protocol used by Cisco SD-WAN to protect the control plane communication, establishing secure tunnels between vSmart controllers and vEdge routers. DTLS provides confidentiality and integrity for the UDP-based control plane traffic.