This week’s class commenced with our usual engaging discussions, reflecting on the key takeaways from last week’s session. We explored Bash Scripting, Cron Jobs, and Ansible. I covered all of it in my last article here. Following that, we dove into Networking Fundamentals.
Networking is the backbone of modern computing. Whether you’re streaming a movie, joining a Zoom call, or managing cloud servers, networks enable systems to connect and share information. To truly understand how data flows across the internet or within your organization, you need a strong grasp of IP addressing, netmasks, the OSI model, and protocols.
Networking Basics
At its core, networking is about connecting devices so they can exchange data. Networks can be as small as two computers connected with a cable (LAN) or as massive as the global internet (WAN).
Types of Networks:
LAN (Local Area Network): Small-scale, like an office or home.
WAN (Wide Area Network): Large-scale, like the internet.
MAN (Metropolitan Area Network): City-wide connectivity.
PAN (Personal Area Network): Very small, like Bluetooth between your phone and headphones.
Real-World Example:
When you log into your office Wi-Fi, you’re connecting to a LAN, which routes you to the wider internet (WAN).
IP Addressing: The Identity of Devices
Every device on a network needs a unique identifier. That’s where IP (Internet Protocol) addresses come in.
Two main types:
IPv4: 32-bit, written as four numbers (e.g.,
192.168.1.1). Supports ~4.3 billion addresses.IPv6: 128-bit, written in hexadecimal (e.g.,
2001:0db8::1). Supports an almost infinite number of devices.
Private vs. Public IPs:
Private IPs: Used within local networks (e.g., 192.168.0.10).
Public IPs: Assigned by ISPs for internet access (e.g., 8.8.8.8, Google DNS).
Example:
Your laptop might have 192.168.1.5 inside your home network but appear as 102.89.221.14 (a public IP) to the wider internet.
IP Addressing and Netmask
An IP address alone doesn’t say much. To understand which part identifies the network and which part identifies the host (device), we use a netmask (or subnet mask).
Subnet Mask Example:
IP:
192.168.1.10Subnet Mask:
255.255.255.0
Here:
Network portion:
192.168.1Host portion:
.10
This tells us that all devices in the 192.168.1.x range are on the same network.
CIDR Notation:
Instead of writing 255.255.255.0, we often write /24, meaning the first 24 bits are the network portion.
Practical Use Case:
In a company office, subnetting ensures different departments (HR, IT, Finance) can be segmented into different networks for performance and security.
The OSI Model: The 7-Layer Framework
The Open Systems Interconnection (OSI) model is a conceptual framework that standardizes networking into 7 layers. Each layer has its own responsibility, and together they ensure smooth communication.
- Physical Layer – Cables, Wi-Fi signals, switches
- Data Link Layer – MAC addresses, Ethernet, ARP
- Network Layer – IP addresses, routers
- Transport Layer – TCP/UDP, ensures reliable delivery
- Session Layer – Session management (e.g., login sessions)
- Presentation Layer – Data format, encryption, compression
- Application Layer – User-facing apps (HTTP, DNS, FTP)
Analogy:
Think of sending a letter.
Physical = the paper/envelope
Data Link = the mailbox system
Network = postal routing
Transport = ensuring delivery (registered mail)
Session = the ongoing correspondence
Presentation = translating the language
Application = the actual message you read
Networking Protocols
Protocols are the rules of communication between devices.
Common Protocols:
HTTP/HTTPS: Web browsing
FTP/SFTP: File transfer
SMTP/IMAP/POP3: Email communication
DNS: Converts names (google.com) into IP addresses
DHCP: Assigns IP addresses dynamically
SSH: Secure remote login to servers
Example:
When you visit www.youtube.com the following happens;
DNS resolves the name to an IP.
Your request travels over HTTP/HTTPS.
TCP ensures the video data arrives reliably.
The data is streamed back and displayed in your browser.
Networking is at the heart of IT and the internet. By understanding IP addressing, subnet masks, the OSI model, and protocols, you unlock the ability to troubleshoot issues, design secure networks, and appreciate how global connectivity works.
From home Wi-Fi setups to enterprise cloud infrastructure, these concepts are the foundation on which modern digital life is built.
Thank you so much for sticking with me all the way to this point! Your effort is truly appreciated. I encourage you to try out all the concepts we've discussed at your earliest convenience, as practice is essential for getting better.
I’d love to hear your thoughts and feedback, so please don’t hesitate to share your insights in the comments section below.
I am Ikoh Sylva a Cloud Computing Enthusiast with few months hands on experience on AWS. I’m currently documenting my Cloud journey here from a beginner’s perspective. If this sounds good to you kindly like and follow, also consider recommending this article to others who you think might also be starting out their cloud journeys to enable us learn and grow together.
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