Networks Under Attacks and Packet/Circuit Switching

Which of the following is a type of passive attack?

• Denial of Service (DoS)

• Man-in-the-Middle (MitM)

• Packet Sniffing

• SQL Injection

Answer explanation

Packet sniffing is a passive attack where an attacker intercepts and analyzes network traffic without altering it. In contrast, DoS, MitM, and SQL Injection are active attacks that disrupt or manipulate data.

What is the main goal of a Denial of Service (DoS) attack?

• Steal user credentials

• Destroy data on a server

• Make a system unavailable to users

• Encrypt data for ransom

Answer explanation

The main goal of a Denial of Service (DoS) attack is to make a system unavailable to users by overwhelming it with traffic or requests, preventing legitimate access. This distinguishes it from other attacks like data theft or encryption.

In a Man-in-the-Middle attack, the attacker:

• Overloads the server with traffic

• Listens to communication without altering it

• Intercepts and possibly alters communication between two parties

• Spoofs the IP address of the user

Answer explanation

In a Man-in-the-Middle attack, the attacker intercepts and may alter communication between two parties, making this choice correct. The other options describe different types of attacks or actions.

Which of the following attacks is commonly used to redirect users to a fake website?

• ARP Poisoning

• DNS Spoofing

• Ransomware

• SQL Injection

Answer explanation

DNS Spoofing is an attack that alters DNS records to redirect users to a fake website, making it the correct choice. ARP Poisoning targets local networks, Ransomware encrypts files, and SQL Injection exploits databases.

Which protocol is often used in spoofing attacks due to its stateless nature?

• TCP

• HTTPS

• SSH

• UDP

Answer explanation

UDP is often used in spoofing attacks because it is a stateless protocol, meaning it does not establish a connection before sending data. This allows attackers to easily forge packets without needing to maintain session information.

What is the main disadvantage of circuit switching?

• Inefficient use of resources

• Delayed data transmission

• Data loss in transit

• Requires packet assembly at the receiver

Answer explanation

The main disadvantage of circuit switching is its inefficient use of resources, as it reserves a dedicated path for the entire duration of the communication, even if no data is being transmitted, leading to wasted bandwidth.

Which of the following is a key advantage of packet switching over circuit switching?

• Fixed bandwidth allocation

• Better for continuous voice transmission

• Handles bursty data efficiently

• No need for addressing in data packets

Answer explanation

Packet switching efficiently handles bursty data by allowing multiple data packets to share the same network resources, unlike circuit switching, which allocates fixed bandwidth for the entire duration of a connection.

Which of the following is true about Circuit Switching?

• Data is broken into packets.

• A dedicated path is established.

• It is used in modern Internet applications.

• Each packet may take a different route.

Answer explanation

Circuit switching establishes a dedicated path for the duration of the communication, ensuring a constant connection. This is unlike packet switching, where data is broken into packets and may take different routes.

Which of the following best describes packet switching?

• Continuous data flow between two devices.

• Data is divided into packets that may travel different paths.

• Data is transmitted in a dedicated circuit.

• A fixed delay for each communication session.

Answer explanation

Packet switching involves dividing data into packets that can take different routes to their destination, optimizing network efficiency. This distinguishes it from continuous data flow or dedicated circuits.

You have a login form on a website with the following input fields: Username: [_________] Password: [_________] Attacker Input SELECT * FROM users WHERE username = '' OR '1'='1' AND password = '' OR '1'='1'; the query bypasses authentication and returns all records or logs the attacker in without valid credentials.

• True

• False

Answer explanation

The attacker's input exploits SQL injection by manipulating the query to always return true ('1'='1'). This allows access without valid credentials, confirming the statement is true.