Certified in Cyber Security (CC) Part 4: Network Concepts
This article is part 4 (of 6) of a series to help you prepare for the ISC2 Certified in Cybersecurity (CC) certification. The CC certification is a foundational certification that covers the core concepts and principles of cybersecurity. It is designed for anyone who wants to enter or progress in the cybersecurity field, regardless of their background or experience.?Find out more at: https://www.dhirubhai.net/pulse/cyber-awareness-month-2023-your-journey-isc2-cc-jean-baptiste-bres
In today's interconnected world, computer networks serve as the digital highways that facilitate the exchange of information, resources, and data. They form the backbone of modern communication, enabling everything from casual internet browsing to intricate corporate infrastructures and global data transmission. While the concept of computer networks may appear straightforward at its core—connecting multiple devices—it encompasses a rich tapestry of intricacies and diversity.
Within the realm of computer networking, various types of networks have emerged, each tailored to specific needs and scenarios. From the intimate confines of your home to the vast expanse of the World Wide Web, these networks underpin the way we live and work. Moreover, the hardware and protocols that make these networks function seamlessly are equally critical.
In this comprehensive exploration of computer network concepts, we will delve into the types of networks that define our digital landscape, understand the vital role played by network devices, decipher the significance of IP addresses and DHCP, and shed light on the essential role of network ports. Furthermore, we will unravel key network terms, elucidate the models governing network communication, and decode the intricate protocols that power our interconnected world.
By the end of this article, you will have a profound understanding of the intricate web of technologies that make the modern digital age possible, and how they shape the way we connect, communicate, and collaborate. So, let's embark on this exploration of computer networks, where the digital meets the practical, and where the possibilities are as boundless as the information they carry.
Type of computer networks
At its core, a computer network is simply two or more computers linked together to share data, information or resources. However, not all networks are created equal. There are many different types of networks, each with its own set of characteristics and uses.
When it comes to computer networking, there are several types of networks that serve different purposes. Here are some of the most common types of networks:
By understanding the different types of networks and their uses, you can better understand how computer networking works and how you can use it in your personal or professional life.
Network Technology
Network Devices
Networks are not just composed of cables running from point to point to connect computers. In order to direct the traffic and ensure communications are optimised, a number of network devices are presents as intermediary relay. The most common devices you will see operating a network are:
Each of these devices plays a critical role in ensuring that a network is functional and secure. By understanding the role of each device, you can better design and manage your network to meet the needs of your organisation.
IP Addresses and DHCP
An IP (Internet Protocol) address is a unique numerical identifier assigned to each device on a network. It allows devices to be identified and located on the internet or within a private network. Think of it like a phone number for a computer or other device.?
In the past, the most common type of IP address was IPv4, which used a 32-bit address format and allowed for about 4 billion unique addresses. ?
To simplify things, IPv4 addresses are typically written in a dotted-decimal notation, where four groups of numbers separated by dots represent the different parts of the IP address. For example, an IPv4 address might look like 192.168.0.1.
However, with the rapid growth of the internet and more devices being connected, IPv4 addresses are becoming scarce.
IPv6 is a newer and more modern version of IP addressing, which uses a 128-bit address format and allows for a significantly larger number of unique addresses. This makes it possible to assign unique addresses to every device on the planet, and then some. IPv6 also provide improved security and quality of service.
IPv6 addresses are typically written as height groups of numbers and letters separated by semi-columns. IPv6 address might look like 2001:0db8:85a3:0000:0000:8a2e:0370:7334.
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DHCP (Dynamic Host Configuration Protocol) is a technology that simplifies the process of assigning IP addresses to devices on a network.
Instead of manually configuring each device's IP address, DHCP automatically assigns IP addresses to devices as they connect to the network. It ensures that each device receives a unique IP address and helps manage the network's available IP addresses efficiently.
DHCP makes it easier to set up and manage networks by automating the IP address assignment process, reducing the chances of address conflicts, and minimising the need for manual configuration. Typically, servers are configured with static IP, so they always keep the same address, and end user devices are configured with dynamically changing IP addresses, meaning that they might get a different IP address every time they reconnect to a given network.
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In summary, IP addresses are unique numerical labels assigned to devices for communication purposes. IPv4 is the original IP addressing system but has limitations on available addresses, while IPv6 is the newer version designed to provide a vast pool of addresses. DHCP simplifies IP address assignment by automatically assigning addresses to devices on a network, making network setup and management easier.
Network Ports
In computer networking, network ports are virtual communication endpoints that allow different applications and services to interact with each other. Think of ports as doors in a computer that allow access to different services. Each port, or door, lead to a specific room where different activities take place. Each port is assigned a unique number, and applications use these numbers to send and receive data over a network.
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Port numbers range from 0 to 65535 and are divided into three categories:
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Network ports play a crucial role in enabling communication between different devices and services on a network. They ensure that data is sent to the correct application or service running on a specific device. By using different port numbers, applications can effectively separate and manage their network traffic, allowing multiple services to coexist and function independently.
Understanding common port numbers used in the industry can help in troubleshooting network issues, configuring firewalls, or ensuring that specific services are accessible. While this is just a brief introduction to network ports, it highlights their significance in facilitating communication between devices and applications across a network.
Others Network Terms
Here's a brief explanation of some additional of the network terms:
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These network terms play essential roles in facilitating communication, identifying devices, and ensuring the smooth operation of networks and internet connectivity.
Network Models
The OSI (Open Systems Interconnection) model and TCP/IP (Transmission Control Protocol/Internet Protocol) model are two protocols that define how data is transmitted over a network.
The OSI model encapsulates data by adding a header and footer to each layer as it moves through the network. The header and footer contain information needed for that particular layer to function and are removed at the receiving end. This process ensures that the data is delivered correctly and helps to prevent errors or data loss.
The OSI model consists of seven layers, each responsible for a specific aspect of network communication. The layers are:
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On the other hand, the TCP/IP model consists of four layers:
Both models take the 1s and 0s from the physical or network interface layer, where the cables or Wi-Fi connect, to the Application Layer, where users interact with the data. The data traverses the network as packets, with headers or footers being added and removed accordingly as they get passed layer to layer. This helps route the data and ensures packets are not lost and remain together.
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It's important to note that while the OSI model has seven layers and the TCP/IP model has four, they both describe similar functions and can be used together to understand network communication.
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TCP/IP also includes a framework organising a set of communication protocols used in the Internet and similar computer networks according to functional criteria.
The foundational protocols are located at the transport layer:
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In addition, the application layer offers a set of protocols used by most applications for providing user services or exchanging application data over the network connections established by the lower-level protocols.
Such protocols include:
Cloud Solutions
Cloud computing has transformed the way businesses and individuals use technology. For a lot of organisations, cloud solutions provide access to powerful computers and software over the internet, without needing to own or manage the network and physical hardware. There are different ways to use cloud services, and various ways to set up cloud environments.
Cloud Service Models
Depending on the model used, the responsibility of various aspects of the solution shift between the customer and the cloud vendor. The figure below presents a high-level view of the usual responsibilities of each party based on the Cloud model selected.
Cloud Deployment Models
Cloud solutions come in various deployment models that organisation can choose from:
In summary, cloud computing comes in various flavours, from renting software and infrastructure to building your own applications. Organisations can choose the deployment model that best suits their requirements, whether it's a public, private, community, or hybrid cloud. The cloud has democratised technology, making powerful resources accessible to businesses and individuals of all sizes.
Conclusion
In the realm of technology, computer networks seamlessly connect our digital world. From the smallest Personal Area Networks (PANs) to the expansive Wide Area Networks (WANs), these networks are the backbone of our digital lives.
We've explored the devices, IP addresses, DHCP, network ports, and critical network terms that define this landscape. Additionally, we've demystified network models and protocols that drive communication.
computer networks are the lifeblood of our interconnected world, transcending geographical boundaries and fostering collaboration on a global scale. They are the essence of modern communication, the foundation upon which the digital age is built.
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Disclaimer: This article is not legal or regulatory advice. You should seek independent advice on your legal and regulatory obligations. The views and opinions expressed in this article are solely those of the author. These views and opinions do not necessarily represent those of HSBC or its staff.
Academic Advisor & Adjunct Faculty at Salt Lake Community College
3 个月I sincerely appreciate your efforts in sharing these critical documents. Thank you!
Chief Executive Officer at CYBER 7
1 年Thank you for sharing such valuable insights