CompTIA Updated PT0-002 Exam Questions and Answers by nikola

-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

Nmap is a tool that can perform network scanning and enumeration by sending packets to hosts and analyzing their responses. The command Nmap -p 445 -n -T4 --open 172.21.0.0/16 would scan for SMB port 445 over a /16 network with the following options:

-p 445 specifies the port number to scan.

-n disables DNS resolution, which can speed up the scan by avoiding unnecessary queries.

-T4 sets the timing template to aggressive, which increases the speed of the scan by sending packets faster and waiting less for responses.

–open only shows hosts that have open ports, which can reduce the output and focus on relevant results. The other commands are not optimal for scanning SMB port 445 over a /16 network when stealth is not a concern and the task is time sensitive.

A DNS poisoning attack is an attack that exploits a vulnerability in the DNS protocol or system to redirect traffic from legitimate websites to malicious ones. A DNS poisoning attack works by injecting false DNS records into a DNS server or resolver’s cache, which is a temporary storage of DNS information. However, if the DNS cache was not refreshed, then the attack would fail, as the target machine would still use the old and valid DNS records from its cache. The other options are not likely causes of the attack failure.

This is the most likely reason for the error because the application is unable to validate the certificate issued by the tester's private root CA. Certificate pinning is a process where an application compares the certificate presented by the server with a predefined set of certificates and only accepts connections if the presented certificate is one of the predefined certificates. This means that the application will reject any certificate that is not in the predefined set, even if it is valid.