Redundancy in Computer Systems and Internet

What is the purpose of redundancy in computer systems?

To increase the speed of data transmission
To preserve operations and data in case of failure (correct)
To limit the scalability of the Internet
To prevent attackers from accessing the internal network

How does the Internet achieve reliability in case of failures?

By reducing fault tolerance
By limiting the number of connections
By dynamically routing data via redundant connections (correct)
By using static routing techniques

What is the role of firewalls in network security?

To prevent attackers from accessing the internal network (correct)
To provide redundancy in data storage
To limit the speed of data transmission
To increase fault tolerance

Which term refers to the ability of the Internet to keep working as it grows?

Scalability (D) Signup and view all the answers

What is the main benefit of building redundancy into the physical systems of the Internet?

Increased fault tolerance and scalability (A) Signup and view all the answers

Why do devices on the Internet often fail at unexpected times?

Because failures occur in groups, such as a whole city (C) Signup and view all the answers

What is the main function of a firewall?

To monitor network traffic and block or allow traffic based on security rules (D) Signup and view all the answers

Which type of firewall is also known as a dynamic firewall?

Stateful firewall (A) Signup and view all the answers

What is a weakness of stateless firewalls when it comes to packet filtering?

They can potentially allow spoofing of address information in a packet (C) Signup and view all the answers

What is a strength of stateful firewalls in comparison to stateless firewalls?

They are able to determine the connection state of packets (D) Signup and view all the answers

Which type of firewall works by inspecting individual packets in isolation?

Stateless firewall (A) Signup and view all the answers

What is a common weakness of stateless firewalls in packet filtering?

They can potentially be spoofed by the sender (B) Signup and view all the answers

Which type of firewall is good for stopping SYN attacks?

Stateful firewall (A) Signup and view all the answers

What is a strength of stateless firewalls in comparison to stateful firewalls?

They can give warnings of a possible attack before it happens (D) Signup and view all the answers

What layer do stateful firewalls operate on?

Transport Layer (A) Signup and view all the answers

What type of firewall is able to view more of the network packet to determine whether to allow or block traffic?

Stateful firewall (A) Signup and view all the answers

What is the significance of building redundancy into the physical systems of the Internet?

It increases the Internet's fault tolerance and helps it scale. Signup and view all the answers

How does the Internet achieve reliability in case of failures?

By building many redundant connections into its physical systems. Signup and view all the answers

What is the role of firewalls in network security?

They provide an essential layer of security and prevent attackers from accessing the internal network in malicious ways. Signup and view all the answers

What is the main function of a firewall?

To prevent unauthorized access and ensure security. Signup and view all the answers

What is the significance of fault tolerance in computer systems?

It allows the system to work around problems and continue functioning even if parts fail. Signup and view all the answers

How does redundancy in computer systems contribute to preserving operations and data?

It ensures that data can be preserved even if part of the system fails. Signup and view all the answers

What is the main difference between stateless and stateful firewalls?

Stateless firewalls inspect individual packets in isolation, while stateful firewalls determine the connection state of packets. Signup and view all the answers

What are the weaknesses of stateless (packet filtering) firewalls?

Address information in a packet can potentially be spoofed by the sender, and data within an allowed packet may contain unwanted data that can be used by attackers to exploit known bugs in the system. Signup and view all the answers

What is an advantage of stateless (packet filtering) firewalls?

They are simple and easy to implement, and they can give warnings of a possible attack before it happens (e.g. by detecting port scans). Signup and view all the answers

What layer do stateful firewalls operate on?

Stateful firewalls operate on the Transport layer. Signup and view all the answers

What is the function of an application gateway firewall?

The application level gateway is a proxy for applications, exchanging data between two parties. Signup and view all the answers

What are the weaknesses of stateful (dynamic) firewalls?

They may require substantial modification of the programs that normally provide transport functions. Signup and view all the answers

What is an advantage of stateful (dynamic) firewalls?

Stateful packet inspectors typically have the same features as static packet filters, but they're able to view more of the network packet to determine whether to allow or block traffic. Signup and view all the answers

What are the three types of firewalls mentioned in the text?

The three types of firewalls mentioned are stateless (packet filtering) firewall, stateful (dynamic) firewall, and application gateway firewall. Signup and view all the answers

What are the potential weaknesses of stateless firewalls when it comes to packet filtering?

Address information in a packet can potentially be spoofed by the sender, and data within an allowed packet may contain unwanted data that can be used by attackers to exploit known bugs in the system. Signup and view all the answers

What are the potential strengths of stateful firewalls in comparison to stateless firewalls?

Stateful firewalls are much more flexible than stateless firewalls, as they can determine the connection state of packets and view more of the network packet to determine whether to allow or block traffic. Signup and view all the answers