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Networking Fundamentals - Documentation Index

Overview

This directory contains comprehensive networking documentation split into focused topics. Each file includes detailed explanations, workflow diagrams, and practical examples.

Documentation Structure

Core Topics

  1. IP Addressing
  2. IPv4 and IPv6 fundamentals
  3. Address classes and structure
  4. Public vs Private IP addresses
  5. APIPA (Automatic Private IP Addressing)

  6. Comprehensive diagrams and examples

  7. Subnetting and CIDR

  8. Subnetting concepts and benefits
  9. Subnet masks explained
  10. 5-step subnetting process
  11. CIDR notation and calculations
  12. Practical subnetting scenarios

  13. Quick reference tables

  14. Ports and Protocols

  15. Port categories and ranges
  16. Common ports reference
  17. TCP vs UDP protocols
  18. Port management and security
  19. Monitoring and troubleshooting

  20. Best practices

  21. Routing and Switching (Original file - to be split)

  22. Routing fundamentals
  23. Routing protocols (OSPF, BGP, EIGRP)
  24. Switching concepts

  25. VLANs and STP

  26. NAT and Firewalls (Original file - to be split)

  27. Network Address Translation
  28. Firewall types and rules
  29. Security groups

  30. Ingress and egress traffic

  31. VPN and SSL/TLS (Original file - to be split)

  32. Site-to-Site VPN
  33. Remote Access VPN
  34. SSL/TLS encryption

  35. Certificate management

  36. DNS (Original file - to be split)

  37. DNS architecture
  38. DNS records (A, AAAA, CNAME, MX, TXT)
  39. DNS resolution process

  40. DNSSEC

  41. Load Balancing (Original file - to be split)

  42. Application Load Balancer (ALB)
  43. Network Load Balancer (NLB)
  44. Gateway Load Balancer (GWLB)
  45. API Gateway
  46. Use case scenarios

Quick Reference

IP Address Classes

Class Range Default Mask Hosts
A 0.0.0.0 - 127.255.255.255 /8 16,777,214
B 128.0.0.0 - 191.255.255.255 /16 65,534
C 192.0.0.0 - 223.255.255.255 /24 254

Common Ports

Port Service Protocol
22 SSH TCP
80 HTTP TCP
443 HTTPS TCP
53 DNS UDP/TCP
3306 MySQL TCP
5432 PostgreSQL TCP

Private IP Ranges

  • Class A: 10.0.0.0/8
  • Class B: 172.16.0.0/12
  • Class C: 192.168.0.0/16

Visual Diagrams Included

Each documentation file includes ASCII diagrams for: - Network topology - Data flow - Protocol workflows - Address structure - Subnetting visualization - Port communication - Load balancing architecture

Learning Path

Beginner

  1. Start with IP Addressing to understand network fundamentals
  2. Learn Subnetting and CIDR for network design
  3. Study Ports and Protocols for application communication

Intermediate

  1. Explore Routing and Switching for network infrastructure
  2. Understand NAT and Firewalls for security
  3. Learn DNS for name resolution

Advanced

  1. Master VPN and SSL/TLS for secure communications
  2. Study Load Balancing for high availability
  3. Practice real-world scenarios and troubleshooting

Practical Examples

Each file includes: - ✅ Real-world scenarios - ✅ Configuration examples - ✅ Troubleshooting guides - ✅ Best practices - ✅ Command references - ✅ Security considerations

Tools and Commands

Network Diagnostics

# IP configuration
ip addr show
ifconfig

# Routing table
ip route show
route -n

# DNS lookup
nslookup example.com
dig example.com

# Port scanning
nmap -p 1-65535 192.168.1.1
netstat -tuln

# Connectivity testing
ping 8.8.8.8
traceroute google.com

Network Monitoring

# Active connections
ss -tuln
netstat -an

# Bandwidth monitoring
iftop
nethogs

# Packet capture
tcpdump -i eth0
wireshark

Additional Resources

Original Content

Images and Diagrams

  • Screenshots and visual aids are referenced in individual files
  • Located in the same directory with descriptive names

Best Practices

Network Design

  1. Plan IP addressing scheme carefully
  2. Use private IP ranges for internal networks
  3. Implement proper subnetting
  4. Document network topology
  5. Use consistent naming conventions

Security

  1. Close unnecessary ports
  2. Implement firewalls
  3. Use encryption (SSL/TLS, VPN)
  4. Regular security audits
  5. Monitor network traffic
  6. Keep systems updated

Performance

  1. Optimize routing
  2. Implement load balancing
  3. Use caching where appropriate
  4. Monitor bandwidth usage
  5. Plan for scalability

Troubleshooting Guide

Common Issues

1. Cannot Connect to Network - Check IP configuration - Verify subnet mask - Test gateway connectivity - Check DNS settings

2. Slow Network Performance - Check bandwidth usage - Verify routing paths - Look for network congestion - Check for broadcast storms

3. DNS Resolution Failures - Verify DNS server settings - Test with alternative DNS (8.8.8.8) - Check DNS cache - Verify firewall rules

4. Port Connection Issues - Verify service is running - Check firewall rules - Test with telnet/nc - Review application logs

Contributing

When adding new networking documentation: 1. Follow the established format 2. Include workflow diagrams 3. Provide practical examples 4. Add troubleshooting sections 5. Include best practices 6. Update this README

Summary

This networking documentation provides: - Comprehensive coverage of networking fundamentals - Visual diagrams for better understanding - Practical examples for real-world application - Troubleshooting guides for common issues - Best practices for network design and security - Quick references for common tasks

Perfect for DevOps engineers, system administrators, and anyone working with network infrastructure.

Last Updated: January 6, 2026
Status: ✅ Core topics documented with diagrams
Next: Complete remaining topics (Routing, NAT, VPN, DNS, Load Balancing)