Network Basics and Security for CS Professional Elective 4.4

What this chapter covers

Network Basics and Security: topics in the order to study them

1. 1Computer Network Basics and TypesStart here because every later topic assumes you know what a network is, and the types (such as LAN, MAN and WAN) and topologies give you the basic vocabulary.
2. 2OSI and TCP/IP Reference ModelsThe layered models give you a map of how data moves, and later you will place protocols, attacks and tools on that map.
3. 3Internet, IP Addressing and Network ProtocolsOnce you know the layers, you can learn which protocols and addresses work at each layer and how the internet ties them together.
4. 4Cyber Threats and Network AttacksWith the network understood, you can see where attacks strike, such as malware, phishing, denial of service and interception.
5. 5Network Security Tools and ControlsControls make sense only after the threats are clear, so you learn firewalls, intrusion detection and prevention, access controls and similar measures as responses to specific attacks.
6. 6Cryptography, Encryption and Digital SignaturesThis topic explains how confidentiality, integrity and authenticity are secured, and it needs the earlier ideas of data in transit and attacks on it.
7. 7Cyber Security Frameworks and StandardsFinish with frameworks and standards, because they bring threats, tools and cryptography together into an organisation-wide approach to managing security.

How to prepare Network Basics and Security

1. Read the chapter once in the study order above without making notes, so you see how the topics link.
2. Build a one-page summary for each topic with the key terms, each in one plain sentence of your own.
3. Draw the OSI and TCP/IP layers from memory and place protocols, attacks and security tools against the right layer.
4. For every threat, write three lines: how it works, what damage it does and which control stops it.
5. Practise two or three case-style questions per topic in the format of provision, analysis and conclusion, and write them in full within a time limit.
6. Compare the frameworks and standards using the same headings, such as purpose, who uses it and what it requires, so you can answer comparison questions quickly.
7. Revise using your one-page summaries every week until the exam, and redraw the layer diagram each time.

Common mistakes in Network Basics and Security

• Memorising the OSI layers as a list without knowing what each layer does.

  Fix: Write one function and one example protocol or device for each layer, and practise placing attacks and tools on the layers.

• Mixing up related terms such as virus, worm and trojan, or IDS and IPS.

  Fix: Keep a short comparison note for each pair that states the key difference in one line.

• Treating encryption and digital signatures as the same thing.

  Fix: Remember the purpose of each: encryption hides content, while a digital signature proves who sent it and that it was not altered.

• Naming a threat in a case answer but not recommending a control.

  Fix: End every answer with the control or compliance step that would prevent or reduce the problem.

• Studying frameworks and standards only by name.

  Fix: For each one, note its purpose and how an organisation would use it, and use only the details given in your study material.

• Skipping written practice and relying on reading.

  Fix: Write timed answers in full sentences and check that each has a definition, an application to the facts and a conclusion.

Last-day revision: Network Basics and Security

• ✓A network is a set of connected devices that share data and resources.
• ✓Know the main network types by size and reach, and the common topologies.
• ✓The OSI model has seven layers and the TCP/IP model has fewer; be able to map one to the other.
• ✓An IP address identifies a device on a network, and you must know the difference between IPv4 and IPv6.
• ✓Protocols are agreed rules for communication; link each common protocol to its purpose.
• ✓Malware, phishing, denial of service and interception are different attacks, so define each separately.
• ✓Firewalls filter traffic, while intrusion detection systems alert and intrusion prevention systems block.
• ✓Encryption protects confidentiality; digital signatures support authenticity, integrity and non-repudiation.
• ✓Symmetric encryption uses one shared key; asymmetric encryption uses a public and private key pair.
• ✓Frameworks and standards give an organisation a structured way to manage security risk.
• ✓In a case answer, name the threat, name the control, then give the compliance recommendation.

Network Basics and Security practice questions

• Which statement correctly compares the OSI model with the TCP/IP model?
• A company has implemented the NIST CSF. Its network team deploys an intrusion detection system that raises alerts on anomalous traffic, and …
• An employee of Sharma Logistics Pvt. Ltd. logs into the company's online banking site. The browser address shows https and a padlock. Which …
• A company secretary of a firm in Pune is asked to describe the network connecting the firm's head office floors and its server room within a…
• Which of the following correctly distinguishes the internet from an intranet in an organisation?
• Under the Information Technology Act, 2000, a person who knowingly conceals or alters computer source code used for a computer network, when…
• A firm's network is divided so that its public web server sits in a separate zone, reachable from the internet but isolated by a firewall fr…
• The NIST Cybersecurity Framework (version 1.1) organises its core activities into five functions. Which sequence lists exactly those five fu…

Network Basics and Security in other exams

The same ground in other exams, if you are preparing for more than one or want another angle on it.

• FRM Part IICase Study: Cyberthreats and Information Security Risks
• CMA FinalInformation Systems Security Audit