Which protocol is used by the REST API to communicate with network devices in the Cisco SD-WAN network?

REST APIs fundamentally operate over HTTP (Hypertext Transfer Protocol), which serves as the underlying communication protocol for web-based services. While often secured with TLS/SSL (making it HTTPS), the core protocol for data exchange is HTTP.

SSL (or TLS) is a security protocol that encrypts HTTP traffic (making it HTTPS), but it is not the application-layer protocol used by REST APIs for communication itself.

IPSec is a network layer security protocol used for securing IP communications, commonly used for VPN tunnels in SD-WAN data plane, but not for REST API communication.

SSH (Secure Shell) is a protocol for secure remote command-line access and file transfer, not the protocol used by REST APIs.