Easy Guide to Networking Basics
*This is the first blog of the CompTIA Network+ Course, which is a beginner-level certification for entering the field of Cybersecurity.
Networking Fundamentals
Networking basics:
Understanding how computers connect and talk to each other in a network.
IP & MAC addresses:
IP addresses (IPv4/IPv6) are digital addresses for devices. MAC addresses are physical hardware IDs for each device.
Subnetting:
Breaking large networks into smaller sections for better performance and management.
OSI & TCP/IP models:
These are layered models that describe how data travels from one device to another.
OSI Model – Detailed Explanation
The OSI (Open Systems Interconnection) model explains how data moves in 7 layers. Each layer has a specific job.
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Physical Layer:
Deals with physical connections like cables and signals. Sends raw bits (0s and 1s).
Example: Ethernet cables, fiber optics, hubs
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Data Link Layer:
Sends data between devices on the same network using MAC addresses.
Example: Switches, MAC address, Ethernet
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Network Layer:
Finds the best route for data using IP addresses.
Example: Routers, IPv4, IPv6
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Transport Layer:
Breaks data into smaller pieces and ensures it arrives correctly.
Example: TCP, UDP
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Session Layer:
Starts and manages communication between devices.
Example: Login sessions, video/audio calls
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Presentation Layer:
Formats, compresses, and encrypts data.
Example: JPEG, MP4, SSL/TLS
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Application Layer:
The layer you interact with through apps like browsers or email.
Example: HTTP, FTP, DNS, Gmail, Chrom
TCP/IP Model
A simpler, 4-layer model used in real-world internet communication.
- Application Layer – Similar to OSI’s top 3 layers
- Transport Layer – Same as OSI
- Internet Layer – Like OSI’s Network Layer
- Network Access Layer – Combines OSI’s Data Link and Physical layers
Protocols:
Standard rules like DNS (website lookup), DHCP (auto IPs), HTTP/S (web browsing), FTP (file transfer), SNMP (monitoring).
Ports:
Special “gates” for communication. Examples:
- Port 80 = HTTP (web)
- Port 443 = HTTPS (secure web)
- Port 21 = FTP (file transfer)
- Port 22 = SSH (secure terminal)
Wireless tech:
Wi-Fi standards (802.11a/b/g/n/ac/ax), Bluetooth (short range), NFC (tap to pay), RFID (tags/scanning).
Cables:
- Cat5e, Cat6: Common Ethernet cables.
- Fiber Optic: Very fast and long-distance.
- Plenum vs. PVC: Fire-safe vs. normal plastic cable jackets.
Network Topologies – (Network Layout Designs)
Topologies describe how computers are arranged in a network. Different types suit different needs.
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Star Topology:
All devices connect to a central switch. Easy to manage, but if the switch fails, everything stops.
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Bus Topology:
All devices share one main cable. Cheap, but if cable fails, the whole network breaks.
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Ring Topology:
Devices are connected in a loop. Data passes from one to the next. One failure can affect the whole ring.
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Mesh Topology:
Every device connects to every other. Very reliable but expensive.
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Hybrid Topology:
Mix of two or more topologies, used in large networks.
Tech (Virtualization, Cloud, Storage)
Virtualization:
Running multiple virtual computers (VMs) on one physical machine. Saves space and resources.
Cloud Storage:
Store files online (like Google Drive or Dropbox), accessible from anywhere.
SAN (Storage Area Network):
A high-speed storage network used by servers for fast access to data.
NAS (Network Attached Storage):
Like a mini file server — allows file sharing over a local network.
Network Implementations
Network devices:
- Router: Sends data between networks
- Switch: Connects devices within a network
- Firewall: Blocks unwanted traffic
- Access Point: Gives Wi-Fi access
- Modem: Connects to internet service provider (ISP)
Routing:
- Static Routing: Manually set paths
- Dynamic Routing: Auto path selection using protocols
Switching:
- VLANs: Virtual LANs divide traffic
- Trunking: Allows VLANs to travel across switches
- Port Mirroring: For traffic monitoring and analysis
Wireless setup:
SSID = Wi-Fi name
WPA2/WPA3 = Security
Channels = Control signal interference
WAN tech:
- MPLS: Fast private networks
- Metro Ethernet: High-speed city-wide network
- DSL/Cable/Satellite: Home internet types
Network services:
- Load Balancer: Spreads traffic across servers
- Proxy Server: Filters and caches web traffic
- VPN Concentrator: Manages secure remote connections
**Stay tuned for Part 2 of CompTIA Network+ **