# Visualizing AWS EC2 Network Traffic and Packet Flows
> Learn how AWS network traffic flows between public and private subnets, NAT Gateways, and IGWs with this technical architectural visualization.

Tags: aws, ec2, vpc, networking, nat-gateway, security-groups, cloud-architecture, traffic-flow
## AWS Network Traffic Simulation
An overview of packet flows focusing on Intra-VPC communication and Internet Egress.

## Architecture Topology
* **Public Subnet:** Contains Instance A & B (Web/App Layer) with direct Internet Gateway (IGW) access.
* **Private Subnet:** Contains Instance C (Backend/DB) routed melalui NAT Gateway.

## Internal Flow Patterns
* **Same Subnet (A ↔ B):** Direct communication within Local VPC CIDR. Uses private IPs (e.g., 10.0.1.10 to 10.0.1.20).
* **Public to Private (A ↔ C):** Traffic crosses boundaries via the VPC Router. Instance A connects to Instance C's private IP.

## External Egress & NAT Gateway
* **Problem:** Private instances lack public IPs.
* **Solution:** Route 0.0.0.0/0 traffic to a NAT Gateway in the Public Subnet.
* **Process:** NAT Gateway translates the source IP to its own Elastic IP for internet access.

## Security Controls
* **Public Layer SG:** Allows Inbound HTTP (80) from 0.0.0.0/0.
* **Private Layer SG:** Restricts Inbound traffic specifically to the SG ID of the Public instances.

## Summary
* Internal traffic is fast and stays within the local network.
* External traffic requires an IGW for public instances and a NAT Gateway for private instances.
* Security Groups should follow the principle of least privilege.
---
This presentation was created with [Bobr AI](https://bobr.ai) — an AI presentation generator.