Networking Concepts Lecture Notes

Introduction

• Instructor: Abishek
• Objective: Understanding networking concepts from fundamentals to advanced levels.
• Duration: 3 hours, divided into five chapters.
• Projects: Two networking-related projects on AWS.
  • Architecture project.
  • Advanced networking concepts like security groups and NSLs.

Key Concepts

IP Address

• A unique address assigned to each device in a network to identify it uniquely.
• Example: Home network with a router and four devices each having a unique IP.
• Importance of IP: Allows tracking, monitoring, and regulating access to websites.

IPv4 and IPv6

• IPv4: Standard for generating unique addresses for each device. Format: 172.x.x.x or 10.x.x.x.
• IPv6: Another standard, not covered here.
• Why IPv4: To maintain proper standards across different networks (home, schools, universities).
• Format: 0-255.0-255.0-255.0-255 (Four bytes or 32 bits).

IP Address Representation

• Each segment separated by a dot can vary from 0-255.
• Representation in bits: 32 bits total, each byte is 8 bits.
• Binary representation explained using bit positions and powers of 2.

Subnets

• Subnetting: Dividing a large network into smaller, manageable network segments (subnets).
• Purpose: Enhances security, privacy, and isolation within networks.
• Private vs Public Subnets:
  • Private: No internet access.
  • Public: Internet accessible.
• Usage in schools, offices to segregate sensitive information networks from general access networks.

CIDR (Classless Inter-Domain Routing)

• Used for defining the network's IP address range and subnet size.
• Example: 172.16.x.x/24 for 256 IP addresses.
• Calculation: 2^(32 - CIDR) gives the number of IPs.

Port Numbers

• Unique numbers assigned to applications in instances (e.g., HTTP: 80, HTTPS: 443).
• Importance of managing ports for security; avoiding conflicts by using unique ports.

Networking Model: OSI Model

• Layers: 7 layers from Application to Physical.
• Role: Explains data journey from one device to another over the internet.

Layers Explained

1. Application Layer: Manages HTTP/HTTPS requests.
2. Presentation Layer: Data encryption.
3. Session Layer: Manages sessions (e.g., login sessions).
4. Transport Layer: Data segmentation, determines protocol (TCP/UDP).
5. Network Layer: Adds source and destination IP addresses.
6. Data Link Layer: Converts data packets to frames (includes MAC address).
7. Physical Layer: Transmits data as electronic signals over cables.

TCP/IP Model

• Simplified version of OSI; combines Application, Presentation, and Session layers.

AWS and Virtual Private Cloud (VPC)

• VPC: Virtual network dedicated to your AWS account.
• Components: Subnets, security groups, route tables, NAT gateways, etc.

VPC Setup

• Public and Private Subnets: Public-facing services in public subnets; databases in private subnets.
• NAT Gateway: Allows private subnet resources to access the internet securely.

Security in AWS

• Security Groups: Instance-level security settings.
• Network ACLs: Subnet-level security settings.
• Shared Responsibility: Security is a collaborative effort between AWS and the user.

Practical Implementation

• Hands-On Demos: Creating VPCs, subnets, routing, load balancing, and implementing security settings in AWS.
• Key Tasks: Configure security groups, NSLs, CIDR ranges, and test network configurations through AWS console.

Conclusion

• Networking concepts involve understanding IP addresses, subnets, ports, and protocols (OSI model).
• Practical application in cloud environments like AWS enhances understanding and provides real-world skills.
• Encouraged to explore further assignments and practice for deeper learning.

These notes cover the fundamental topics discussed in the class, focusing on networking basics, practical AWS implementations, and security configurations. Use these as a study guide for understanding networking concepts and AWS cloud configurations.