Chapter 34: AWS Networking
AWS Cloud Networking.
Many people think “networking = VPC + subnets + security groups” and stop there. But real-world AWS networking in 2026 is a complete layered system that decides whether your app is fast, secure, reliable, cheap, globally available, or a complete nightmare during peak traffic.
Let me explain it like we’re sitting together with a big Hyderabad city + India map on the whiteboard — slow, step-by-step, real analogies from daily life in Hyderabad, actual startup examples, current 2026 features, and exactly how the pieces fit together.
1. What is “AWS Cloud Networking”? (The Big Picture – No Jargon First)
AWS Cloud Networking = all the tools, services, and concepts AWS gives you to connect, secure, route, accelerate, protect, and monitor traffic between:
- Your users (mobile, browser, IoT devices)
- Your AWS resources (EC2, Lambda, ECS, RDS, S3…)
- Other AWS accounts / regions
- Your on-premise data center / office
- The public internet
Think of it like building and managing roads, traffic signals, toll booths, flyovers, traffic police, and speed cameras for your entire application city.
Without good networking:
- Users in Hyderabad wait 5 seconds for your page to load
- Hackers easily reach your database
- One EC2 crash takes down everything
- You pay 3× more for data transfer
- Compliance team rejects your app
With good networking:
- Sub-second loads even during IPL finals
- Zero-trust security model
- 99.99%+ uptime
- Predictable bills
- Easy multi-region / hybrid setup
2. The Main Layers of AWS Cloud Networking (2026 View)
| Layer / Concept | What It Does (Simple) | Key Services Involved | Real Hyderabad Analogy |
|---|---|---|---|
| 1. Global Backbone | Super-fast private network connecting all Regions & Edge Locations | AWS Global Network, Direct Connect, Global Accelerator | The NHAI highways + Expressways connecting all cities |
| 2. Regions & AZs | Where your resources physically live | All services are Region-specific | Telangana state (Region) → Gachibowli, Banjara Hills, Hi-Tech City (AZs) |
| 3. VPC (Virtual Private Cloud) | Your private, isolated network inside a Region | VPC, Subnets, Route Tables, Internet Gateway | Your own gated community with private roads |
| 4. Connectivity Inside VPC | How resources talk to each other & to internet | Subnets (public/private), NAT Gateway, NACLs, Security Groups | Internal lanes, main gates, security guards |
| 5. Load Balancing & Routing | Distribute traffic, route intelligently | ALB, NLB, Global Accelerator, Route 53 | Traffic police + flyovers + smart signals |
| 6. Edge Acceleration & CDN | Make content fast for users worldwide | CloudFront, Global Accelerator, Lambda@Edge | Local Swiggy dark stores / delivery boys |
| 7. Hybrid & Multi-Cloud | Connect AWS to on-premise, other clouds | Direct Connect, Site-to-Site VPN, Transit Gateway | Expressway to your old office / other city |
| 8. Security & Protection | Firewall, DDoS, encryption, zero-trust | Security Groups, NACLs, WAF, Shield, Network Firewall | Main gate guards, CCTV, anti-theft alarms |
3. Deep Dive: The Most Important Pieces (With Hyderabad Examples)
A. VPC – Your Private Network (The Foundation)
- Every AWS account gets a default VPC per Region
- You almost always create custom VPCs (especially in production)
Typical production VPC in Hyderabad 2026:
|
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VPC: 10.0.0.0/16 (ap-south-2) ├── Public Subnet A (10.0.1.0/24) → web servers, ALB nodes ├── Public Subnet B (10.0.2.0/24) ├── Private Subnet A (10.0.10.0/24) → ECS/Fargate tasks, RDS, Lambda ├── Private Subnet B (10.0.11.0/24) ├── Internet Gateway → public internet access ├── NAT Gateway (in public subnet) → private resources reach internet (updates, API calls) ├── Route Tables → direct traffic correctly |
Analogy: Your apartment society (VPC)
- Main gate = Internet Gateway
- Public parking + visitor area = Public Subnets
- Private flats + internal roads = Private Subnets
- Security guard at gate + society rules = Security Groups / NACLs
B. Security Groups & NACLs – The Guards
- Security Groups = stateful firewalls attached to resources (EC2, ECS tasks, RDS, Lambda) → Allow inbound/outbound rules (e.g., allow HTTP 80 from anywhere, allow SSH 22 only from your IP)
- NACLs = stateless firewalls at subnet level → Less common now (Security Groups usually enough)
Example rule (very common):
- Security Group on web server: Inbound: TCP 443 (HTTPS) from 0.0.0.0/0 Inbound: TCP 80 from 0.0.0.0/0 (redirect to HTTPS) Outbound: All traffic allowed
C. Load Balancing – Traffic Police
- Application Load Balancer (ALB) → Layer 7 (HTTP/HTTPS) – most common
- Network Load Balancer (NLB) → Layer 4 (TCP/UDP) – ultra-low latency, static IP
- Gateway Load Balancer → for 3rd-party appliances (firewalls)
Hyderabad example: Your food delivery app → ALB in front of 20 ECS Fargate tasks across 3 AZs User hits https://app.com → ALB distributes to healthy tasks → if one AZ fails → ALB stops sending traffic there → app stays up.
D. CloudFront + Edge Locations – Speed Layer
- CloudFront = AWS CDN
- Caches content at 750+ Edge Locations (including Hyderabad PoPs)
Example: User in Uppal watches Telugu short video → CloudFront serves from Hyderabad Edge Location → <10 ms latency instead of 50–100 ms from ap-south-2 Region data center.
4. Quick Hands-On: See Basic Networking in Console
- VPC console → Your VPCs → see default VPC or create custom
- Subnets → see public/private split
- Security Groups → see rules (HTTP/HTTPS allowed?)
- Load Balancers → see ALB/NLB attached to services
- CloudFront → see distributions (if you have any)
Summary Table – AWS Cloud Networking Cheat Sheet (2026)
| Question | Answer (Beginner-Friendly) |
|---|---|
| What is AWS Cloud Networking? | All tools/services to connect, secure, route, accelerate traffic |
| Most important service? | VPC (your private isolated network) |
| Public vs Private subnets? | Public = direct internet access; Private = no direct internet |
| How to secure traffic? | Security Groups (stateful), NACLs (stateless), WAF, Shield |
| How to make app fast globally? | CloudFront + Edge Locations (CDN) |
| How to load balance? | ALB (HTTP/HTTPS), NLB (TCP/UDP) |
| Best practice for production? | VPC with public + private subnets, multi-AZ, Security Groups, ALB |
Teacher’s final note: AWS Cloud Networking is the “roads & traffic system” of your cloud city. Build it wrong → traffic jams, accidents, high tolls, angry users. Build it right (VPC + multi-AZ + ALB + CloudFront + Security Groups) → smooth, fast, safe, cheap ride for everyone.
Got it? This is the “make sure your app can actually talk to the world” lesson.
Next?
- Step-by-step: Build a secure VPC from scratch (with subnets, NAT, IGW)?
- Deep dive on ALB + target groups + health checks?
- Or CloudFront + S3 + ACM for fast, secure website?
Tell me — next whiteboard ready! 🚀🌐
