Does UDP use a handshake?

• A. Yes
• B. No
• C. Only with certain ports
• D. Only in IPv6

Answer: (B)

UDP is a connectionless, datagram-based transport protocol. It sends individual packets without establishing a connection first, so there is no handshake to set up state between sender and receiver. Each UDP datagram is independent, carrying its own source and destination ports, and delivery is not guaranteed, nor is the order preserved. Because there’s no setup phase or maintained connection state, UDP itself does not perform a handshake.

Note that some applications or higher-layer protocols that run over UDP may implement their own handshake (for example, DTLS or certain custom protocols). But that handshake belongs to the application layer, not to UDP itself.