What is the purpose of a demilitarized zone on a network?

Attacker Rony installed a rogue access point within an organization's perimeter and attempted to intrude into its internal network. Johnson, a security auditor, identified some unusual traffic in the internal network that is aimed at cracking the authentication mechanism. He immediately turned off the targeted network and tested for any weak and outdated security mechanisms that are open to attack.
What is the type of vulnerability assessment performed by Johnson in the above scenario?

John, a disgruntled ex-employee of an organization, contacted a professional hacker to exploit the organization.
In the attack process, the professional hacker installed a scanner on a machine belonging to one of the victims and scanned several machines on the same network to identify vulnerabilities to perform further exploitation.
What is the type of vulnerability assessment tool employed by John in the above scenario?

Windows LAN Manager (LM) hashes are known to be weak.
Which of the following are known weaknesses of LM? (Choose three.)

What would you enter if you wanted to perform a stealth scan using Nmap?