When enabling TLS Proxy in SD-WAN, what is the first step in establishing traffic flows through the proxy?

The correct answer is to establish the TCP connection between client↔proxy and between proxy↔server. TLS Proxy operates as a man-in-the-middle, requiring two distinct TCP connections: one between the client and the proxy, and another between the proxy and the destination server. This dual connection setup is fundamental before any TLS handshake or decryption can occur. The other options describe subsequent steps or related concepts, but not the first step in establishing traffic flows through the proxy: "The sender authenticates devices and users; the receiver verifies the signature by decrypting with the sender's public key" describes part of the TLS handshake, which happens after TCP connections are established. "Certificate authorities issue certificates for hosts, network devices, or users used by TLS Proxy" describes a prerequisite for TLS, but not the first step in establishing traffic flow through the proxy itself. "When decryption policy is enabled, a client hello is received by Unified Threat Defense to determine the decryption action" describes a later stage of the TLS handshake and policy enforcement, which also occurs after the initial TCP connections are in place.