CNSP Exam Dumps : Certified Network Security Practitioner (CNSP)

Protocols are defined by their transport layer usage (TCP or UDP), impacting their security and performance characteristics.

Why D is correct:SSH (Secure Shell) uses TCP (port 22) for reliable, connection-oriented communication, unlike the UDP-based options. CNSP contrasts TCP and UDP protocol security.

Why other options are incorrect:

A:SNMP uses UDP (ports 161, 162) for lightweight network management.

B:NTP uses UDP (port 123) for time synchronization.

C:IKE (IPsec key exchange) uses UDP (ports 500, 4500).

References:CNSP "Network Protocols" (Section on Transport Layer) identifies SSH as TCP-based, others as UDP.

Online attacks require real-time interaction with a target system (e.g., a login interface), whereas offline attacks occur without direct system interaction, typically after obtaining data like password hashes. A rainbow table attack is an offline method that uses precomputed tables of hash values to reverse-engineer passwords from stolen hash databases, distinguishing it from the other options, which are online.

Why B is correct:Rainbow table attacks are performed offline after an attacker has already acquired a hash (e.g., from a compromised database). The attacker matches the hash against precomputed tables to find the plaintext password, requiring no interaction with the target system during the attack. CNSP classifies this as an offline password recovery technique.

Why other options are incorrect:

A:Brute force attacks involve repeatedly submitting password guesses to a live system (e.g., via SSH or a web login), making it an online attack.

C:Password spraying attacks test a few common passwords across many accounts on a live system, also an online attack aimed at avoiding lockouts.

D:Phishing attacks trick users into submitting credentials through fake interfaces (e.g., emails or websites), requiring real-time interaction and thus classified as online.

References:CNSP "Password Attack Methodologies" (Section on Online vs. Offline Attacks) defines rainbow table attacks as offline and contrasts them with online methods like brute force and phishing.

In Linux, password hashes are stored in a secure file to protect user authentication data. The evolution of Linux security practices moved password storage from plaintext or weakly protected files to a more secure location.

Why C is correct:The /etc/shadow file is the standard location for storing password hashes in modern Linux systems. This file is readable only by the root user, enhancing security by restricting access. It contains encrypted password hashes (typically using algorithms like SHA-512), along with user details such as password expiration policies. CNSP documentation on Linux security emphasizes /etc/shadow as the authoritative source for password hashes, replacing older methods.

Why other options are incorrect:

A. /etc/passwd:Historically, /etc/passwd stored passwords in plaintext or weakly hashed forms (e.g., using DES), but modern systems use it only for user account information (e.g., UID, GID, home directory) and reference /etc/shadow for hashes.

B. /etc/password:This is not a valid file in the Linux file system; it appears to be a typographical error or misunderstanding, with no recognized role in password storage.

D. /usr/bin/shadow:/usr/bin contains executable binaries, not configuration or data files like password hashes. /etc/shadow is the correct path.

References:CNSP "Linux Authentication Mechanisms" (Section on Password Storage) details the transition to /etc/shadow for enhanced security and contrasts it with /etc/passwd.