netcat

Question 1

netcat

Answer 1

netcat is a simple unix utility which reads and writes data across network connections, using TCP or UDP protocol.

Question 2

nc

• c shell commands, Use /bin/sh to exec.
• e filename, Program to exec after connect.
• b, Allow broadcasts.
• g gateway, source-routing hop points up to 8.
• G num, source routing pointer: 4, 8, 12…
• i secs, Delay interval for lines sent, ports scanned.

Answer 2

• k, Set keepalive on socket.
• l, Listen mode for inbound connects.
• n, Numeric IP only, no DNS.
• o file, hex dump of traffic.
• p port, Local port number
• r, Randomize local and remote ports.
• q secs, Quit after EOF on stdin and delay of seconds.

Question 3

nc

• s addr, Local source address.
• T tos, Set Type Of Service.
• t, Answer TELNET negotiation.
• u, UDP mode.

Answer 3

• v, verbose
• w secs, Timeout for connects and final net reads.
• C, Send CRLF as line editing.
• z, zero I/O mode.