Practice question (2022)

Answer ALL the questions in this section.

Question One (20 Marks) Models are useful because they help us understand difficult concepts and complicated systems. The Open Systems Interconnection Model (OSI Model) is the most popular and commonly used of these models. The idea behind the OSI model is to provide a framework for both designing network systems and for explaining how they work.

Discuss in detail the various layers and their functions in the OSI model. (Discuss in detail and also provide practical examples)

Question Two (20 Marks) Computers can be positioned on a network in different ways relative to each other. They can have different levels of control over shared resources. They can also be made to communicate and share resources according to different schemes. You are the network administrator at High Flying Inc. As the Network and Security Administrator, you are required to put a report together for senior management, detailing the following:

a. What are the two fundamental types of networks? (5 marks) b. Discuss in detail the advantages and disadvantages of the both networks. (10 marks) c. Contrast both these networks and make your recommendation. (5 marks)

Question Three (20 Marks) A network attack or security incident is defined as a threat, intrusion and denial of service or other attack on a network infrastructure that will analyse your network and gain information to eventually cause your network to crash or to become corrupted. In many cases, the attacker might not only be interested in exploiting software applications but also try to obtain unauthorised access to network devices. Unmonitored network devices are the main source of information leakage in organisations. In most organisations, every email message, every Web page request, every user logon and every transmittable file is handled by a network device. Under some setups, telephone service and voice messaging are also handled by network devices. If the attacker is able to own your network devices, then they own your entire network. Network attacks cut across all categories of software and platform type.

There are at least seven (7) types of network attacks i.e. spoofing, sniffing, mapping, hijacking, Trojans, DoS and DDoS, and social engineering.

As the Network and Security Administrator of High Flying Inc, advise the board of five (5) of the various security solutions or preventative measures that may be taken to eliminate the above security threats. (Provide a detailed explanation and also include practical examples)