Netcat command flags

• -l: Listen mode (default is client mode).
• -L: Listen harder, supported only on the Windows version of Netcat. This option makes Netcat a persistent listener that starts listening again after a client disconnects.
• -u: UDP mode (default is TCP).
• -p: Local port (in listen mode, this is the port that is listened on).
• -e: Program to execute after a connection has been established.
• -n: Don't perform a DNS lookup (name resolution) on the names of the machines on the other side.
• -z: Zero I/O mode.
• -w(N): Timeout for connections. A Netcat client or listener with this option will wait for N seconds to make a connection. For example, w1 or w2.
• -v: Be verbose.
• -vv: Be very verbose.