The key difference is that an Intrusion Prevention System (IPS) is installed in line with network traffic, allowing it to actively block threats. In contrast, an Intrusion Detection System (IDS) only monitors and alerts without actively blocking traffic.
Breakdown of Options:
A). An IPS needs to be installed in line with traffic and an IDS does not. # Correct answer. IPS actively prevents threats, while IDS only detects them.
B). An IPS is signature-based and an IDS is not. - False, both can use signature-based detection.
C). An IPS is less susceptible to false positives than an IDS. - False, both can produce false positives, depending on configurations.
D). An IPS requires less administrative overhead than an IDS. - False, IPS requires more administrative effort due to real-time blocking decisions.
Reference:
CompTIA Network+ (N10-009) Official Study Guide - Domain 3.4: Explain network security devices.

When the hosts file is altered, local name resolution is compromised, and domain queries are redirected to malicious IP addresses. This is a form of DNS spoofing/poisoning, where false mappings trick users into visiting fraudulent websites.
B). Phishing typically uses emails or messages to trick users, not local file modification.
C). VLAN hopping is a Layer 2 attack to gain unauthorized network access, unrelated to DNS.
D). ARP poisoning manipulates ARP tables on a LAN to reroute traffic, not name resolution.
References (CompTIA Network+ N10-009):
Domain: Network Security - DNS poisoning/spoofing, host file manipulation, endpoint attacks.

*The total number of devices = (150 + 10) users × 2 IPs per user = 320 devices
*Class C (D) supports a maximum of 254 hosts (2^8 - 2), which is too small.
*Class B (B) supports 65,534 hosts (2^16 - 2), making it the best choice.
*Why not the other options?
*Class A (C): Supports millions of addresses, which is overkill for 320 devices.
*Class D (A): Used for multicast, not for device addressing.
Reference:
CompTIA Network+ (N10-009) Official Guide - Chapter 7: IP Addressing and Subnetting

Port Address Translation (PAT) allows multiple internal devices to share a single public IP address by assigning each device a unique port number. This is the most common method used in environments where many systems need internet access but there are limited public IP addresses.

SNMPv3 is the version of the Simple Network Management Protocol that introduces security enhancements, including message integrity, authentication, and encryption. Unlike previous versions (v1 and v2c), SNMPv3 supports encrypted communication, ensuring that data is not transmitted in plaintext. This provides confidentiality and protects against eavesdropping and unauthorized access.References:CompTIA Network+ study materials.