Computer Science Module: Network Security
16 Questions
5 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the primary purpose of network security?

  • To make all user data publicly available
  • To completely prevent all network traffic
  • To eliminate the need for user authentication
  • To protect vital information while allowing necessary access (correct)
  • Which of the following is NOT a reason for implementing network security?

  • Providing authentication and access control
  • Guaranteeing availability of resources
  • Encouraging open access to sensitive information (correct)
  • Protecting personal data
  • What does a firewall do in network security?

  • Limits access to hosts by filtering packets based on rules (correct)
  • Prevents all forms of communication over the network
  • Automatically installs all necessary security updates
  • Acts as a web server for client requests
  • Which component is commonly used in combination with firewalls for enhanced security?

    <p>Intrusion Detection Systems</p> Signup and view all the answers

    What type of firewall filters packets based on rules?

    <p>Packet filtering firewalls</p> Signup and view all the answers

    What is the role of a De-Militarized Zone (DMZ) in a network?

    <p>To house public-facing servers while separating them from the internal network</p> Signup and view all the answers

    What vulnerability is commonly associated with social engineering attacks?

    <p>Taking advantage of human psychology for unauthorized access</p> Signup and view all the answers

    Which statement best describes packet sniffing?

    <p>It captures and analyzes data packets traveling over the network.</p> Signup and view all the answers

    What is the main purpose of well-known port numbers?

    <p>To identify specific service types on a host</p> Signup and view all the answers

    Which of the following port numbers is used for Secure Shell (SSH)?

    <p>22</p> Signup and view all the answers

    What type of attack aims to make a network service unusable?

    <p>Denial of Service</p> Signup and view all the answers

    Which protocol suite is used to secure Internet Protocol communications?

    <p>IPSec</p> Signup and view all the answers

    What is a common solution for defending against packet sniffing?

    <p>Encrypting the data</p> Signup and view all the answers

    What method is often employed in a dictionary attack?

    <p>Using common password lists</p> Signup and view all the answers

    Which of the following is NOT a TCP port used for a specific application?

    <p>202 for IMAP</p> Signup and view all the answers

    What behavior characterizes social engineering attacks?

    <p>Manipulating individuals to disclose information</p> Signup and view all the answers

    Study Notes

    International & Access Foundation Programmes - Computer Science Module, Semester II, Part 5: Networks: Network Security

    • Overview of Network Security:
      • What is network security?
      • Why is network security needed?
      • Who is vulnerable to network attacks?
      • Common security attacks and countermeasures:
        • Firewalls & Intrusion Detection Systems
        • Denial of Service Attacks
        • TCP Attacks (Spoofing)
        • Packet Sniffing
        • Social Engineering

    Why Network Security is Needed

    • Protecting Vital Information: Protects sensitive data like trade secrets, medical records, and personal information while allowing authorized access for those who need it.
    • Authentication and Access Control: Provides methods to confirm the identity of users and control access to resources
    • Logins, Passwords, Biometrics:
    • Resource Availability: Ensures 99.995% reliability of resources

    Firewalls

    • Basic Problem: Network applications and protocols often have security vulnerabilities
    • Difficulty: Keeping up with changes makes securing hosts challenging
    • Solution:
      • Firewall administrators restrict access to end hosts
      • Firewalls are regularly updated
    • Firewall Analogy: A firewall is like a castle with a drawbridge – only one access point
    • Hardware/Software: Firewalls can be hardware or software
    • Routers: Some routers have built-in firewall functionality
    • Software Firewalls: Unix, Windows XP/7/8, and Mac OS X have built-in software firewalls
    • DMZ (De-militarized Zone): A security buffer between the internet and internal network. Separates web servers, email servers, and web proxies.
    • Filtering Packets: Firewalls are used to filter packets based on defined rules. Packet filtering firewalls operate by examining packets and applying these rules.
    • Windows 7 Default Firewall Configuration:
      • 135/tcp open loc-srv
      • 139/tcp open netbios-ssn
      • 445/tcp open microsoft-ds
      • 1025/tcp open NFS-or-IIS
      • 3389/tcp open ms-term-serv
      • 5000/tcp open UPnP

    Ports

    • Definition: Ports are endpoints of communication within an operating system.
    • Well-known Ports: 1024 port numbers identify specific services on a host (e.g., http://www.example.com:8080).
    • Port Association: A port is always associated with an IP address of a host.

    Typical TCP Ports

    • 21: File Transfer Protocol (FTP)
    • 22: Secure Shell (SSH)
    • 23: Telnet (remote login)
    • 25: Simple Mail Transfer Protocol (SMTP)
    • 53: Domain Name System (DNS)
    • 80: Hypertext Transfer Protocol (HTTP)
    • 110: Post Office Protocol version 3 (POP3)
    • 119: Network News Transfer Protocol (NNTP)
    • 123: Network Time Protocol (NTP)
    • 143: Internet Message Access Protocol (IMAP)
    • 161: Simple Network Management Protocol (SNMP)
    • 194: Internet Relay Chat (IRC)
    • 443: HTTP Secure (HTTPS)

    Types of Attacks

    • Intrusion Detection: Monitors a network for suspicious activity based on known patterns.
    • Dictionary Attack (Brute Force): Tries various passwords from a dictionary or database.
    • Denial of Service (DoS): Overloads a network service, making it unusable.
    • TCP Attacks: Manipulates TCP packets to cause harm. An attacker can inject malicious data into the TCP stream, making recipients believe it came from a legitimate source.
    • Packet Sniffing: A host intercepts and examines data on a network or broadcast medium.
    • Social Engineering: Manipulating or tricking people into divulging sensitive information.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Description

    Explore the essential elements of network security in this module from the International & Access Foundation Programmes. Understand the reasons network security is crucial, learn about common security attacks and countermeasures such as firewalls, and gain insights into authentication methods. This quiz will test your knowledge on securing networks against various threats.

    More Like This

    Firewalls and Network Security Quiz
    5 questions
    Network Security Basics
    8 questions
    Network Security Overview
    40 questions
    Use Quizgecko on...
    Browser
    Browser