CompTIA N10-009 Network+ Exam Dumps and Practice Test Questions Set 5 Q61-75
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Question 61
Which type of routing protocol calculates the best path based on a combination of bandwidth, delay, load, and reliability metrics?
A) Distance-vector
B) Link-state
C) Path-vector
D) Hybrid
Answer: B) Link-state
Explanation:
Link-state routing protocols determine the best path by calculating a cost metric for each route, often based on multiple parameters including bandwidth, delay, load, and reliability. They maintain a complete map of the network topology using a link-state database, which is updated through periodic advertisements that inform all routers about the status of their links. Each router independently computes the shortest or optimal path to each destination using algorithms such as Dijkstra’s shortest path first. By evaluating multiple factors, link-state protocols can make more sophisticated routing decisions compared to distance-vector protocols that rely primarily on hop count. Link-state protocols converge faster and are less susceptible to routing loops, making them suitable for large and complex networks. They also support features like route summarization, authentication of routing updates, and hierarchical designs such as areas in OSPF to optimize scalability and reduce routing overhead. These protocols ensure that traffic flows efficiently and adapts to network changes with minimal disruption, enhancing overall network performance.
Distance-vector protocols calculate routes based on the number of hops to a destination rather than considering multiple metrics. They share their routing tables periodically with neighboring routers, which can lead to slower convergence and susceptibility to routing loops. While simpler and easier to configure, distance-vector protocols are not as precise in selecting the most optimal path, and they are less suited for large or complex networks. Distance-vector protocols also lack the complete network map that link-state protocols maintain, which limits their ability to adapt intelligently to changes in network conditions.
Path-vector protocols, such as BGP, are used primarily for inter-domain routing between autonomous systems. They track the path that routes traverse and make routing decisions based on policies, autonomous system numbers, and path attributes rather than metrics like bandwidth or delay. While essential for wide-area routing on the Internet, path-vector protocols are not designed for calculating optimal internal paths based on link metrics, so they do not meet the requirements for evaluating bandwidth, delay, load, and reliability.
Hybrid protocols combine elements of distance-vector and link-state protocols to leverage the advantages of both. They may maintain topology information in a limited fashion and use hop count or metrics to optimize routing. However, hybrid protocols are not universally implemented and may not offer the same precision in evaluating multiple metrics as pure link-state protocols. The ability to account for bandwidth, delay, load, and reliability is a distinguishing feature of link-state protocols, which use complete network topology information to calculate optimal paths.
The correct answer is link-state because it integrates multiple metrics into routing decisions, maintains a comprehensive network map, and uses efficient algorithms to determine the best paths. By considering bandwidth, delay, load, and reliability, link-state protocols optimize network performance for real-time applications, high-throughput demands, and complex topologies. They are scalable, resilient, and able to converge quickly in the event of network changes. In addition to fast convergence, link-state protocols minimize routing loops by ensuring that all routers have an accurate and consistent view of the network. The protocol can detect failed links and recompute routes in real time, allowing data to flow over alternative paths without interruption.
Link-state protocols support authentication mechanisms that prevent unauthorized routers from injecting false routing information. They also allow for route summarization to reduce the size of routing tables and advertisements in large networks, which improves efficiency and reduces CPU and memory usage on routers. Link-state protocols, like OSPF and IS-IS, support hierarchical network designs, which further enhance scalability by dividing the network into areas and reducing the frequency and size of updates exchanged between routers.
The use of link-state routing protocols ensures that optimal routes are chosen based on the most relevant network metrics. This capability allows organizations to design networks that can meet performance requirements for applications sensitive to latency, jitter, and throughput. Because link-state protocols consider multiple metrics, they can distribute traffic more effectively, avoiding congested or unreliable links while maximizing overall network efficiency. In environments where redundancy and fault tolerance are required, link-state protocols can rapidly adapt to link or node failures, automatically recalculating paths and maintaining connectivity without requiring manual intervention.
Unlike distance-vector protocols, which propagate only hop counts and rely on neighbors for information, link-state protocols provide each router with a complete view of the network, ensuring decisions are accurate and independent. Unlike path-vector protocols, which focus on policy-based routing between autonomous systems, link-state protocols are designed for internal networks to optimize performance and reliability. Hybrid protocols attempt to combine advantages, but link-state protocols remain the most robust for calculating paths using multiple metrics such as bandwidth, delay, load, and reliability. Their comprehensive approach to routing, fast convergence, and adaptability to changing network conditions make them the ideal choice for optimizing network traffic and ensuring consistent, reliable performance across enterprise and large-scale networks.
Question 62
Which type of firewall inspects traffic at the application layer and can block traffic based on content, such as URLs or keywords?
A) Packet-filtering firewall
B) Stateful firewall
C) Application firewall
D) Circuit-level gateway
Answer: C) Application firewall
Explanation:
An application firewall is a network security device that inspects traffic at the application layer, enabling it to evaluate the content of communications. Unlike lower-layer firewalls, which rely on IP addresses, ports, and protocol types, application firewalls examine specific application protocols such as HTTP, FTP, or SMTP. By inspecting the content of traffic, an application firewall can enforce policies based on URLs, keywords, file types, or other data patterns. This enables the firewall to block malicious content, prevent unauthorized access, or filter sensitive information. Application firewalls are particularly useful for web-based applications, email servers, and other high-level services where threats may be embedded in legitimate traffic. They provide a higher level of granularity, allowing administrators to permit or deny specific functions within applications, thereby enhancing security without completely blocking the entire service.
A packet-filtering firewall examines packets at the network or transport layer, evaluating source and destination IP addresses, ports, and protocols. It does not inspect the payload of the packet in depth and therefore cannot block traffic based on content such as URLs or specific data patterns. While efficient and fast, packet-filtering firewalls are limited in their ability to protect against attacks embedded within legitimate application traffic, such as SQL injection or malicious file uploads.
A stateful firewall keeps track of the state of active connections and makes filtering decisions based on connection state and session information. It ensures that only packets belonging to valid, established connections are permitted. While more secure than simple packet-filtering firewalls, stateful firewalls do not inherently inspect application-layer content and cannot selectively block specific actions within an application.
A circuit-level gateway monitors TCP or UDP sessions between hosts to ensure that connection setup and teardown follow proper protocols. It does not inspect the contents of the messages beyond session state, and therefore cannot block traffic based on application content. Circuit-level gateways are useful for ensuring protocol compliance, but do not provide the fine-grained content inspection capabilities required for blocking malicious or sensitive application traffic.
Application firewalls can operate as proxy servers or integrated inline devices. They support deep packet inspection, allowing policies to be applied to HTTP requests, email messages, and FTP commands. By analyzing payload data, they can prevent attacks, enforce regulatory compliance, and control access to specific content or application features. Application firewalls are critical in environments where threats may bypass network-layer defenses, such as web applications or cloud-based services, providing a robust layer of security that complements traditional firewalls.
Question 63
Which wireless network standard operates in the 2.4 GHz band and supports data rates up to 600 Mbps using MIMO technology?
A) 802.11a
B) 802.11g
C) 802.11n
D) 802.11ac
Answer: C) 802.11n
Explanation:
The 802.11n wireless standard operates primarily in the 2.4 GHz band, although it also supports 5 GHz operation, and can achieve data rates up to 600 Mbps using multiple-input multiple-output (MIMO) technology. MIMO allows the use of multiple antennas for simultaneous transmission and reception, significantly improving throughput and reliability. This standard also introduced channel bonding, which combines two 20 MHz channels into a 40 MHz channel, increasing data rates further. 802.11n retains backward compatibility with 802.11b and 802.11g devices operating in the 2.4 GHz band, facilitating gradual network upgrades. It also incorporates enhancements such as frame aggregation, block acknowledgments, and short guard intervals to improve efficiency and reduce latency. These features make it suitable for high-bandwidth applications like video streaming, online gaming, and large file transfers in both home and enterprise environments.
802.11a operates in the 5 GHz band and does not use MIMO technology. It provides data rates up to 54 Mbps and is less common today because of its higher cost and limited range compared to 2.4 GHz standards. Its primary advantage is reduced interference, but it does not offer the throughput improvements that 802.11n provides.
802.11g operates in the 2.4 GHz band with a maximum data rate of 54 Mbps. While it is backward compatible with 802.11b devices, it does not use MIMO or support channel bonding, limiting its maximum throughput. It provides moderate performance suitable for basic internet browsing, but cannot meet the demands of high-bandwidth applications.
802.11ac is a Wi-Fi standard designed to operate exclusively in the 5 GHz frequency band, offering significant improvements in speed, capacity, and overall network performance compared to earlier standards such as 802.11n. One of its primary advancements is the use of wider channel bandwidths, which can extend up to 80 MHz or even 160 MHz, allowing more data to be transmitted simultaneously and increasing throughput. In addition, 802.11ac employs higher-order modulation, specifically 256-QAM (Quadrature Amplitude Modulation), which encodes more bits per symbol and further enhances data transfer rates. Another key feature is multi-user MIMO (MU-MIMO), which enables an access point to communicate with multiple client devices simultaneously rather than sequentially. This improves efficiency and reduces latency in high-density environments where many devices are connected at once. With these enhancements, 802.11ac can achieve gigabit-level throughput, making it suitable for bandwidth-intensive applications such as video streaming, online gaming, and large file transfers. However, a limitation of 802.11ac is its exclusive use of the 5 GHz band, which means it does not support the 2.4 GHz frequency. While this restriction reduces interference from older devices and common household electronics, it also limits range compared to 2.4 GHz networks. Overall, 802.11ac is a later-generation Wi-Fi standard designed for high-speed modern networks, delivering substantial performance improvements through wider channels, advanced modulation, and MU-MIMO, but it does not meet requirements for 2.4 GHz operation.
The correct answer is 802.11n because it uniquely combines 2.4 GHz operation with MIMO technology and channel bonding to achieve data rates up to 600 Mbps. Its backward compatibility and efficiency features make it highly versatile for both home and enterprise networks.
Question 64
Which IPv6 address type is designed to communicate with all devices on a single local link?
A) Global unicast
B) Link-local
C) Multicast
D) Anycast
Answer: B) Link-local
Explanation:
Link-local IPv6 addresses are automatically configured on all IPv6-enabled interfaces and are used to communicate with other devices on the same local link. They typically begin with the prefix FE80::/10. Link-local addresses do not require a global or routable IP and are not forwarded by routers, which makes them ideal for operations such as neighbor discovery, routing protocol communication, or local troubleshooting. Every IPv6 interface must have a link-local address, even if it also has a global unicast address. Link-local communication is essential for enabling initial network connectivity, address resolution, and auto-configuration services in IPv6 networks.
Global unicast addresses are routable across the Internet and assigned uniquely to enable wide-area connectivity. They differ from link-local addresses because they can be used for communication beyond the local link. Multicast addresses allow communication with a group of devices, but they are not confined to a single link and may be routed across networks depending on scope. Anycast addresses deliver packets to the nearest device among a group of potential recipients and are primarily used for load balancing or high availability, rather than local link communication.
The correct answer is link-local because it is automatically assigned, non-routable, and designed specifically for communication on the same local link. It is fundamental to IPv6 operation, ensuring that devices can communicate within their subnet and support essential services before obtaining global addresses.
Question 65
Which network service translates hostnames to IP addresses for client devices?
A) DHCP
B) DNS
C) NAT
D) SNMP
Answer: B) DNS
Explanation:
DNS, or Domain Name System, is a network service that translates human-readable hostnames into IP addresses that devices use for communication. When a client needs to reach a server, it queries a DNS server to resolve the hostname into an IP address. DNS supports hierarchical organization with domains, subdomains, and authoritative servers for scalability. It also allows caching of responses to improve performance and reduce query times. Without DNS, users would need to memorize numeric IP addresses, making networking far less user-friendly.
DHCP automatically assigns IP addresses to clients but does not resolve hostnames. NAT translates IP addresses between private and public networks, but is unrelated to hostname resolution. SNMP monitors and manages network devices, but does not perform translation between names and IP addresses.
The correct answer is DNS because it provides the essential service of mapping hostnames to IP addresses, enabling user-friendly access to network resources, facilitating routing, and supporting the usability of the internet and enterprise networks. It is a critical component of both internal and external network infrastructure.
Question 66
Which WAN technology encapsulates Ethernet frames into MPLS labels to provide efficient and scalable transport between sites?
A) VPN
B) Frame Relay
C) MPLS
D) ISDN
Answer: C) MPLS
Explanation:
MPLS, or Multiprotocol Label Switching, is a WAN technology that provides efficient and scalable transport between sites by encapsulating Ethernet frames or other Layer 2 frames into labels. These labels are used by routers to make forwarding decisions, eliminating the need to perform traditional routing lookups based on IP addresses. MPLS can handle multiple types of traffic, including IP, ATM, and Ethernet, and allows for the creation of virtual private networks (VPNs), traffic engineering, and quality of service (QoS). The primary benefit of MPLS is its ability to establish predetermined, high-priority paths through the network, which reduces latency, optimizes bandwidth usage, and enhances reliability for critical applications. MPLS networks assign labels at the ingress router, and intermediate routers forward packets based on the label, making the process faster than IP-based routing alone. MPLS supports hierarchical and scalable topologies, allowing service providers to efficiently manage large networks with multiple customers, while providing isolation and security through VPNs. It also enables advanced features like load balancing across multiple paths, prioritization of time-sensitive traffic, and fast reroute capabilities in case of link failures.
VPNs, or virtual private networks, provide secure communication over public networks but rely on underlying transport methods such as MPLS, the Internet, or other WAN technologies. VPNs focus on security and encryption rather than transport optimization, and they do not inherently improve forwarding efficiency like MPLS does. While VPNs can run over MPLS networks, they are not a transport mechanism by themselves.
Frame Relay is a legacy WAN technology that uses virtual circuits to transmit data between sites. It operates at Layer 2 and was widely used before the advent of MPLS and broadband WAN technologies. Frame Relay is limited in bandwidth efficiency, scalability, and flexibility, making it less suitable for modern enterprise applications. It does not provide the same level of traffic engineering, QoS, or multi-protocol transport as MPLS.
ISDN, or Integrated Services Digital Network, provides circuit-switched connections over traditional phone lines. It is a narrowband technology that offers limited bandwidth and is rarely used in modern enterprise WANs. ISDN is suitable only for small-scale, low-speed connections, unlike MPLS, which can scale to high-capacity, multi-site networks with sophisticated traffic management.
The correct answer is MPLS because it encapsulates frames into labels for fast forwarding, supports multiple protocols, and enables efficient WAN transport. By using label switching, MPLS reduces routing overhead, optimizes bandwidth utilization, and ensures predictable performance for critical applications. Its scalability, flexibility, and advanced features make it the standard for modern enterprise and service provider WANs.
Question 67
Which IPv4 classful network has a default subnet mask of 255.255.0.0?
A) Class A
B) Class B
C) Class C
D) Class D
Answer: B) Class B
Explanation:
Class B IPv4 networks have a default subnet mask of 255.255.0.0. This allows for 16 bits for host addresses and 16 bits for network addresses, providing 65,534 usable host addresses per network. Class B addresses range from 128.0.0.0 to 191.255.255.255, making them suitable for medium to large-sized networks. Classful addressing was commonly used in early networking, although it has been largely replaced by CIDR (Classless Inter-Domain Routing) for more flexible allocation.
Class A networks have a default subnet mask of 255.0.0.0, providing a very large number of host addresses per network but fewer total networks. Class A addresses range from 1.0.0.0 to 126.255.255.255 and are typically used for extremely large organizations or service providers.
Class C networks have a default subnet mask of 255.255.255.0, supporting 254 usable host addresses per network. They are suitable for smaller networks, such as branch offices or small LANs.
Class D addresses are reserved for multicast traffic and do not have a traditional subnet mask. They range from 224.0.0.0 to 239.255.255.255 and are used for sending data to multiple hosts simultaneously rather than point-to-point communication.
The correct answer is Class B because it balances the number of networks and hosts for medium-sized deployments and provides the 255.255.0.0 default subnet mask. Understanding classful addressing is essential for legacy systems, network design, and subnetting practices. Class B networks remain a reference for understanding IPv4 architecture and address allocation strategies.
Question 68
Which VPN type creates a secure connection over the internet using encryption and authentication, allowing remote users to access a private network?
A) Site-to-Site VPN
B) Remote Access VPN
C) MPLS VPN
D) Leased Line
Answer: B) Remote Access VPN
Explanation:
A Remote Access VPN allows individual users to securely connect to a private network over the internet. It uses encryption and authentication to ensure that traffic between the remote user and the corporate network is protected from interception and tampering. Remote access VPNs often use protocols such as SSL/TLS or IPsec to secure the tunnel and provide confidentiality and integrity. They allow employees to work remotely while accessing internal resources such as file servers, applications, and databases. Remote access VPN clients authenticate users, establish encrypted tunnels, and route traffic securely to the corporate network. This provides security, privacy, and access control even over untrusted networks like public Wi-Fi. Remote access VPNs are scalable for large numbers of users and support features like split tunneling, client-based software, and two-factor authentication to enhance security.
Site-to-site VPNs connect entire networks rather than individual users. They establish a secure tunnel between branch offices or data centers over public networks, but are not designed for individual remote user access. MPLS VPNs use multiprotocol label switching to create private connections between sites but rely on service provider infrastructure rather than client-based remote access. Leased lines are physical point-to-point connections and do not provide encryption or tunneling over the public internet, making them fundamentally different from VPNs.
The correct answer is Remote Access VPN because it specifically allows individual users to securely connect to a private network from remote locations, protecting data and maintaining privacy through encryption and authentication mechanisms.
Question 69
Which type of attack floods a network with ICMP echo requests, overwhelming devices and preventing legitimate traffic from being processed?
A) Man-in-the-Middle
B) ARP Spoofing
C) Smurf Attack
D) DNS Amplification
Answer: C) Smurf Attack
Explanation:
A Smurf attack is a network-layer denial-of-service attack in which the attacker sends a large number of ICMP echo request packets to the broadcast address of a subnet, with the source address spoofed to the victim’s IP. All devices on the subnet respond to the spoofed IP, flooding the victim with traffic. This can overwhelm the target, disrupt legitimate communications, and potentially crash the system. Smurf attacks exploit broadcast amplification to magnify the traffic directed at the victim.
Man-in-the-Middle attacks intercept and modify communications between two parties, but do not rely on ICMP flooding. ARP spoofing involves sending false ARP messages to redirect traffic, but it does not flood the network with echo requests. DNS amplification attacks exploit misconfigured DNS servers to send large responses to a victim using a small query, but the mechanism relies on DNS rather than ICMP.
The correct answer is Smurf attack because it specifically uses ICMP echo requests to a broadcast address, causing an amplified denial-of-service condition by overwhelming the target device. Proper network configuration, such as disabling directed broadcasts and filtering ICMP traffic, mitigates Smurf attacks.
Question 70
Which cloud deployment model provides infrastructure, platform, and software services over the internet for multiple organizations in a shared environment?
A) Private Cloud
B) Public Cloud
C) Hybrid Cloud
D) Community Cloud
Answer: B) Public Cloud
Explanation:
A public cloud is a cloud computing model in which infrastructure, platforms, and software services are provided over the internet to multiple organizations in a shared environment. Public clouds are managed by third-party providers, such as AWS, Microsoft Azure, or Google Cloud, and customers share the underlying hardware resources. Public clouds offer scalability, elasticity, and cost efficiency because resources are shared, and users pay only for what they consume. Security measures, redundancy, and management are handled by the provider, reducing the operational burden on customers. Services include virtual machines, storage, databases, development platforms, and SaaS applications. Public clouds enable rapid deployment, global access, and minimal upfront investment.
Private clouds are dedicated environments for a single organization, providing more control but requiring capital investment. Hybrid clouds combine private and public resources, balancing flexibility with control. Community clouds are shared by organizations with common concerns but remain smaller in scale.
The correct answer is public cloud because it provides shared infrastructure, platform, and software services over the internet for multiple tenants, delivering cost-effective, scalable, and managed solutions suitable for a wide range of organizations.
Question 71
Which protocol is used to securely synchronize clocks on network devices and provides authentication and encryption?
A) NTP
B) SNTP
C) NTPv4 with Autokey
D) RADIUS
Answer: C) NTPv4 with Autokey
Explanation:
NTPv4 with Autokey is a version of the Network Time Protocol that provides secure time synchronization for network devices. Time synchronization is critical in networks for logging, security, and coordination of time-sensitive applications. NTPv4 with Autokey enhances traditional NTP by providing cryptographic authentication of time servers and messages, preventing attackers from injecting false timestamps or manipulating device clocks. In distributed networks, accurate and trusted time is essential for protocols that rely on timestamps, such as Kerberos for authentication, certificate validation for secure communications, and transaction logging in databases or financial systems.
Standard NTP operates over UDP and provides accurate time synchronization by exchanging timestamps with reference clocks, typically within milliseconds over LANs and tens of milliseconds over WANs. While it ensures precision, standard NTP does not inherently provide mechanisms to verify the authenticity of time sources, making it vulnerable to man-in-the-middle attacks or spoofing. If an attacker successfully manipulates time synchronization, it can lead to security breaches, failed authentication, or erroneous logging of network events, which complicates forensic analysis.
SNTP is a simplified version of NTP designed for devices that do not require precise synchronization. SNTP provides time updates without complex algorithms for error correction or authentication, making it suitable for lightweight devices but inadequate for environments requiring security or high precision. SNTP does not offer cryptographic authentication and is therefore susceptible to tampering, unlike NTPv4 with Autokey, which ensures that time updates are both accurate and trustworthy.
RADIUS is an authentication, authorization, and accounting protocol, unrelated to time synchronization. It secures access to network resources but does not provide clock synchronization or timestamp verification. While RADIUS plays a critical role in network security, it does not address the need for accurate or secure timing across devices, which is essential for maintaining network consistency and integrity.
NTPv4 with Autokey uses public-key cryptography to sign time messages, ensuring that devices can verify the authenticity of the time source before adjusting their clocks. This prevents unauthorized or malicious sources from altering system time, which could compromise security or network operations. Devices configured to use NTPv4 with Autokey can securely synchronize with hierarchical time sources, such as Stratum 1 servers connected to atomic clocks, and then distribute accurate time to lower-stratum devices within the network.
Accurate time synchronization is also critical for logging and auditing in security-conscious environments. System logs from multiple devices must have consistent timestamps to correlate events, investigate incidents, and meet compliance requirements. Without secure time synchronization, logs may be unreliable, hindering troubleshooting and forensic investigations. NTPv4 with Autokey ensures both precision and security, supporting reliable network operation.
The correct answer is NTPv4 with Autokey because it combines accurate time distribution with cryptographic authentication, preventing spoofing and ensuring that all network devices maintain consistent, trustworthy time. It is particularly valuable in large-scale enterprise networks, financial institutions, cloud environments, and critical infrastructure systems, where precise and secure timestamps are vital for security, auditing, and operational consistency.
Question 72
Which type of wireless antenna provides a focused, directional signal to cover long distances?
A) Omnidirectional
B) Yagi
C) Dipole
D) Patch
Answer: B) Yagi
Explanation:
A Yagi antenna is a directional wireless antenna that provides a focused signal to cover long distances. It consists of multiple elements: a driven element, a reflector, and one or more directors, which together concentrate the radio frequency energy in a specific direction. By focusing energy, a Yagi antenna can achieve higher gain and greater range compared to omnidirectional antennas, which radiate energy evenly in all directions. Yagi antennas are commonly used in point-to-point wireless links, long-distance Wi-Fi connections, or in environments where signals must be directed precisely to reach a target. The directional nature reduces interference from unwanted sources, enhances signal strength toward the intended receiver, and improves overall communication reliability in long-range deployments.
Omnidirectional antennas radiate signals in all directions, providing broad coverage but lower range and gain compared to directional antennas. They are suitable for environments where devices are distributed around a central access point, but are less effective for long-distance point-to-point links.
Dipole antennas are simple, half-wave elements that are often used for basic signal reception and transmission. While effective for general coverage, dipole antennas have moderate gain and are not designed for focused, long-distance communication.
Patch antennas are flat, directional antennas commonly used for short-range communication, such as in indoor Wi-Fi or GPS applications. While they provide some directionality, they do not offer the extended range or high-gain characteristic of Yagi antennas.
The correct answer is Yagi because it provides a focused, directional signal with high gain, making it ideal for long-distance wireless communication. Its design minimizes interference, maximizes signal strength, and is widely used in point-to-point links, rural internet connections, and environments requiring precise targeting of signals over extended distances.
Question 73
Which cloud service model provides a platform for developers to build, test, and deploy applications without managing underlying infrastructure?
A) IaaS
B) PaaS
C) SaaS
D) DaaS
Answer: B) PaaS
Explanation:
Platform as a Service, or PaaS, is a cloud service model that provides a complete development and deployment environment over the internet. It allows developers to build, test, and deploy applications without worrying about the underlying infrastructure, such as servers, storage, networking, or operating systems. PaaS typically includes development tools, databases, middleware, and runtime environments. Developers can focus on writing code and managing applications while the cloud provider handles maintenance, scaling, updates, and security of the underlying platform. PaaS enhances productivity by reducing the time and effort needed for infrastructure management and provides tools for collaboration, version control, and application lifecycle management.
IaaS, or Infrastructure as a Service, provides virtualized computing resources such as virtual machines, storage, and networking, but the user is responsible for managing the operating system and applications. SaaS delivers fully managed applications to end-users over the internet without requiring development, such as email or CRM solutions. DaaS, or Desktop as a Service, provides virtual desktops accessible remotely but does not serve as a development platform.
The correct answer is PaaS because it abstracts infrastructure management, enabling developers to focus solely on application logic and functionality. It simplifies deployment, improves scalability, and accelerates development cycles, making it ideal for modern software development workflows in cloud environments.
Question 74
Which attack exploits software vulnerabilities by injecting malicious code into input fields or data streams?
A) Phishing
B) SQL Injection
C) Cross-site Scripting
D) Man-in-the-Middle
Answer: B) SQL Injection
Explanation:
SQL Injection is an attack that exploits software vulnerabilities in applications that interact with databases. Attackers input malicious SQL statements into input fields or data streams to manipulate the database. This can lead to unauthorized access, data extraction, modification, or deletion. SQL injection occurs when applications do not properly validate or sanitize user inputs, allowing attacker-controlled commands to execute on the backend database. It is one of the most common web application attacks and can compromise sensitive information such as credentials, financial records, or personal data.
Phishing is a type of cyberattack that relies on social engineering to deceive users into revealing sensitive information such as usernames, passwords, financial details, or personal data. Unlike attacks that exploit software vulnerabilities, phishing targets human behavior by creating a sense of urgency, trust, or curiosity. Attackers typically craft emails, text messages, or websites that appear to come from legitimate sources, such as banks, social media platforms, or online service providers. For example, a phishing email may claim that a user’s account has been compromised and prompt them to click a link to verify their credentials. When the user follows the link, they are often directed to a fraudulent website designed to look identical to the legitimate service, where any information entered is captured by the attacker. Phishing can also involve malicious attachments that, when opened, install malware capable of stealing credentials, logging keystrokes, or providing remote access to the attacker. The effectiveness of phishing lies in exploiting trust and human error, making user awareness and training essential components of prevention.
Cross-site scripting, or XSS, is a web-based attack that exploits vulnerabilities in web applications to inject malicious scripts into web pages viewed by other users. Unlike phishing, which directly targets human behavior, XSS targets technical weaknesses in websites or web applications. When a user accesses a page containing an XSS payload, the malicious script executes in their browser, often without their knowledge. This script can perform a variety of malicious actions, such as stealing session cookies, capturing login credentials, redirecting the user to a malicious site, or manipulating page content to display fraudulent information. There are multiple types of XSS, including reflected, stored, and DOM-based, each differing in how the script is delivered and executed. For instance, reflected XSS occurs when user-supplied input is immediately returned by the server without proper sanitization, while stored XSS involves malicious scripts being saved on the server for repeated execution whenever the affected page is accessed. Preventing XSS typically requires careful input validation, output encoding, and implementing security headers that mitigate script execution in browsers.
Man-in-the-Middle, or MitM, attacks involve intercepting communications between two parties to eavesdrop, modify, or inject data without either party’s knowledge. Unlike phishing or XSS, which either deceive users or exploit web application vulnerabilities, MitM attacks focus on intercepting data in transit, often on unencrypted channels. Attackers can capture sensitive information such as passwords, session tokens, or financial transactions, and in some cases, manipulate communications to redirect traffic, inject malicious commands, or impersonate one of the parties. While MitM attacks compromise the confidentiality and integrity of communications, they are fundamentally different from SQL injection attacks, which target databases by injecting malicious queries to retrieve, modify, or delete stored data. MitM attacks do not directly interact with backend databases or exploit SQL vulnerabilities; their impact is limited to the interception and potential alteration of ongoing communication streams.
Phishing, XSS, and MitM attacks represent distinct categories of cyber threats. Phishing relies on deceiving users to voluntarily provide sensitive information, XSS exploits web application vulnerabilities to execute malicious scripts in users’ browsers, and MitM attacks intercept communications between two parties without directly interacting with databases or web application inputs. Each attack targets different layers of the security landscape—human behavior, application logic, and network communication—highlighting the importance of layered security defenses that include user education, secure coding practices, and encryption for data in transit.
The correct answer is SQL Injection because it directly targets database vulnerabilities via malicious code input, allowing attackers to manipulate, steal, or corrupt data within backend systems. Proper input validation, parameterized queries, and secure coding practices are essential to prevent these attacks.
Question 75
Which layer of the OSI model is responsible for logical addressing and routing between networks?
A) Transport
B) Network
C) Data Link
D) Physical
Answer: B) Network
Explanation:
The Network layer, which corresponds to Layer 3 of the OSI model, plays a critical role in enabling communication between devices across multiple networks. Its primary function is logical addressing and routing, which allows devices to send and receive data beyond a single local network. Devices at this layer are identified using IP addresses, which provide a unique identifier for each device on the network and allow packets to be correctly delivered from source to destination. Routing, another key function of the Network layer, involves determining the optimal path for data packets to travel through interconnected networks. Routers operate at this layer, examining the destination IP address of each packet and forwarding it along the most efficient route toward its destination. Protocols such as IPv4 and IPv6 define the structure of these logical addresses, along with mechanisms for routing, fragmentation, and reassembly of packets when they traverse networks with varying maximum transmission unit sizes. IPv4, the most widely deployed protocol, uses 32-bit addresses, while IPv6 expands the address space to 128 bits to accommodate the growing number of devices on the Internet.
The Transport layer, or Layer 4, builds upon the services of the Network layer by ensuring reliable end-to-end delivery of data between applications running on different devices. This layer provides mechanisms for error detection, retransmission of lost packets, and flow control, ensuring that communication is accurate and complete. Transmission Control Protocol, or TCP, is a connection-oriented transport protocol that guarantees delivery, establishes a session between sender and receiver, and sequences data so it arrives in the correct order. User Datagram Protocol, or UDP, is a connectionless alternative that provides minimal overhead, allowing for faster transmission without guarantees of delivery or order, which is suitable for applications like streaming or gaming where speed is prioritized over reliability. By abstracting reliability and flow control from the lower layers, the Transport layer enables application developers to focus on functionality rather than network management.
Below the Network and Transport layers, the Data Link layer, or Layer 2, ensures reliable frame delivery within a single network segment. It handles physical addressing using Media Access Control (MAC) addresses, detects errors in frames using checksums, and manages access to the shared physical medium to prevent collisions. The Physical layer, or Layer 1, is responsible for transmitting raw bits across the physical medium, whether electrical signals on copper wires, light pulses in fiber optic cables, or radio waves in wireless networks. Together, these layers work in concert to provide end-to-end communication: the Physical and Data Link layers manage local transmission and framing, the Network layer handles addressing and routing across networks, and the Transport layer ensures reliable, ordered delivery of data to applications.
The correct answer is the Network layer because it manages logical addressing and path determination, enabling devices to communicate across different subnets and networks. Efficient routing and addressing at this layer are essential for connectivity, scalability, and performance in modern IP networks.