Exam PT0-002 topic 1 question 89 discussion

-z zero-I/O mode [used for scanning] -v verbose example output of script: 10.0.0.1: inverse host lookup failed: Unknown host (UNKNOWN) [10.0.0.1] 22 (ssh) open (UNKNOWN) [10.0.0.1] 23 (telnet) : Connection timed out https://unix.stackexchange.com/questions/589561/what-is-nc-z-used-for

D. Scanning a network for specific open ports The script is using the command "nc -zv" which stands for "netcat -z -v" which is used to check if a specific port is open on a remote IP address. The script is looping through a range of IP addresses on the 10.100.100 network and attempting to connect to the specified ports (22, 23, 80, and 443) on each IP. This is a method of scanning a network to check which specific ports are open, also known as port scanning. The script is not performing any action related to service vulnerabilities or shell recovery/creation.

"-z": Specifies that nc should not send any data to the target host, but instead just check if the port is open. This is also known as a "zero I/O mode" scan.

D. Scanning a network for specific open ports. The script is using the nc (netcat) command with the -zv options to scan a range of IP addresses (10.100.100.1-10.100.100.254) and specific ports (22, 23, 80, 443) to check for open ports.