Which NetCat option enables UDP mode?

• A. -e
• B. -u
• C. -w
• D. -z

Answer: (B)

Using UDP mode in NetCat is controlled by a specific flag that tells the tool to switch from its default TCP behavior to UDP datagrams. NetCat’s default is to establish a TCP connection, which is a reliable, stream-oriented transport. When you include the UDP flag, NetCat stops trying to create a persistent TCP connection and instead sends and receives UDP datagrams to the target.

The reason this flag is the best fit for enabling UDP is that UDP is connectionless and does not guarantee delivery, ordering, or acknowledgment. This is exactly what the flag changes: it tells NetCat to use the UDP protocol for its transport, making it suitable for interacting with UDP services or simply generating UDP traffic for testing.

For context, the other common flags are unrelated to protocol selection: one flag runs a program on connect, which is about executing commands rather than selecting the transport; another sets a timeout for operations; and another toggles a zero-I/O scanning mode. None of these enable UDP mode.