INTRODUCTION TO COMPUTER NETWORKS

Question 1

What is a computer network?

Answer 1

A connection of two or more computers for the purpose of communication of information and the sharing of resources.

Question 2

What is a bit?

Answer 2

Protocol Data Units in the lower physical layer

Question 3

What are protocols?

Answer 3

Rules that govern data communication eg STMP and FTP

Question 4

What is media?

Answer 4

channels over which messages travel in a network eg wired or wireless

Question 5

What are packets?

Answer 5

Pieces of a message in the network layer

Question 6

What is a PDU?

Answer 6

Protocol Data Unit- Data in a network eg bits and packets

Question 7

What is a topology?

Answer 7

Network lay-out or plan. Could be physical (eg star bus etc) or logical (in terms of configuration)

Question 8

Define configuration

Answer 8

Process of assigning network settings, policies, flows and controls. (Basically the arrangement of the elements of the network)

Question 9

Define downtime

Answer 9

A state whereby the network is functioning below baseline settings (optimum expectation)

Question 10

What is SLA?

Answer 10

Service-level-agreement- An agreement between a service provider and a client. Eg Facebook and its clients

Question 11

What is uptime?

Answer 11

State whereby the network is functioning above optimum expectation

Question 12

What is a domain?

Answer 12

An administrative grouping of multiple private computer networks or local hosts within the same infrastructure. It defines entities eg .co.ke is a company in Kenya and how networks are configured eg collision domain

Question 13

What are addresses?

Answer 13

Unique identifiers in a network eg IP, MAC, Port number etc.

Question 14

What are the qualities of a network?

Answer 14

1. Maintainability- Failed components should be restored to a particular condition within a specified period.
2. Manageability- Should be easy to control.
3. Scalability- Ability of a network to expand or scale down as per an organizations requirements
4. Security- Data in a network should be secure and safe from CIA violations.
5. Fault tolerance- The network should continue operating despite of failures and malfunctions of components
6. Quality of Service (Qos)- Refers to any technology that manages data traffic to reduce packet loss, latency and jitter on a network

Question 15

Describe the CIA Triad

Answer 15

• Confidentiality. Your data should be visible and accessible only to those whom you choose to see it.
• Integrity. The data you see and store should be reliable and accurate, and should not be tampered with. You need to be able to trust this data.
• Availability. Your data should be accessible when you want it, including after a mishap or disaster.

Question 16

What are the advantages of networking?

Answer 16

• Increases Connectivity and Communication
• Allows for Data Sharing
• Allows for Hardware Sharing
• Provides Internet Access
• Internet Access Sharing
• Enhances Data Security and Management
• Performance Enhancement and Balancing

Question 17

What are the disadvantages of networking?

Answer 17

• Network Hardware, Software and Setup Costs
• Hardware and Software Management and Administration Costs
• Undesirable Sharing eg in certain topologies
• Illegal or Undesirable Behavior eg hacking
• Data Security Concerns

Question 18

What are the functions of a network?

Answer 18

1. Communication – Through platforms such as email, mobile, chat, social media
2. Decision making – Networks in information systems are a source of data which greatly influences decision making.
3. Monitors –surveillance, time logging, illegal activities.
4. Security – forensics –Government
5. Resource sharing – network printer, files etc
6. System auditing

Question 19

Differentiate between a node and a host

Answer 19

A network node is any device participating in a network. A host is a node that participates in user applications, either as a server, client, or both. A server is a type of host that offers resources to the other hosts.

Question 20

What is a host

Answer 20

All computers that are connected to a network and participate directly in network communication are classified as hosts. Hosts can be called end devices. Some hosts are also called clients. However, the term hosts specifically refers to devices on the network that are assigned a number (IP address) for communication purposes.

Question 21

What is a client?

Answer 21

Clients are a type of host. Clients have software for requesting and displaying the information obtained from the server. An example of client software is a web browser, like Chrome or FireFox. A single computer can also run multiple types of client software.

Question 22

What is a server?

Answer 22

Servers are computers with software that allow them to provide information, like email or web pages, to other end devices on the network. Each service requires separate server software. For example, a server requires web server software in order to provide web services to the network.

Question 23

Give examples of server software

Answer 23

• The email server runs email server software. Clients use mail client software, such as Microsoft Outlook, to access email on the server.
• The web server runs web server software. Clients use browser software, such as Windows Internet Explorer, to access web pages on the server.
• The file server stores corporate and user files in a central location. The client devices access these files with client software such as the Windows File Explorer.

Question 24

Give examples of intermediary devices

Answer 24

Wireless Router, LAN Switch, Router, Multilayer switch, Firewall appliance