Where in the TLS handshake is the Server Name Indication (SNI) value carried?

• A. In the ClientHello
• B. In the ClientHello extension for Server Name Indication
• C. In the ServerHello
• D. In the Certificate

Answer: (B)

SNI is carried by the client in the TLS handshake as a dedicated extension inside the ClientHello that specifies the host name being connected to. The server uses that server_name value, provided early in the handshake, to select the appropriate certificate before proceeding with the rest of the exchange. It isn’t placed in the ServerHello or in the Certificate messages, which carry server-selected parameters and the actual certificate after the handshake has started. This design lets a server hosting multiple domains on a single IP present the correct certificate based on the requested hostname.