Which protocol is enabled by default on tunnels to detect loss, latency, jitter, and path failures in Cisco SD-WAN?

BFD (Bidirectional Forwarding Detection) is enabled by default on tunnels in Cisco SD-WAN to rapidly detect link failures and monitor path characteristics like loss, latency, and jitter. This real-time monitoring is crucial for intelligent path selection and ensuring optimal application performance. TLS (Transport Layer Security) is used for secure communication but doesn't monitor path quality. OMP (Overlay Management Protocol) is the routing protocol for the SD-WAN overlay, responsible for advertising routes and policies, not for detecting tunnel health. BGP (Border Gateway Protocol) is an exterior gateway protocol used for routing between autonomous systems and is not the default mechanism for tunnel health monitoring in SD-WAN.