Week 2 Worklog

Week 2 Objectives:

• Learn fundamental AWS networking concepts (VPC, Subnets, Routing, Security, Connectivity).
• Understand how to manage traffic flow and secure workloads inside VPC.
• Gain insights into AWS connectivity options (Peering, Transit Gateway, VPN, Direct Connect).
• Explore Elastic Load Balancing for distributing application traffic.

Tasks to be carried out this week:

Week 2 Achievements

1 Studied Amazon VPC & Networking concepts, including:

CloudCity – Analogy for the Entire VPC

Imagine the components in a VPC as a city.

1. Amazon VPC – The City

• VPC = the city you build in the cloud.
• Has a fixed area (CIDR block).
• You own the whole infrastructure, divide it into districts, and manage traffic.

2. Subnets – Neighborhoods

• Subnet = a neighborhood inside the city.
• Each neighborhood belongs to one district (Availability Zone).
• Public neighborhoods (connected to the highway) vs. private neighborhoods (internal only).

3. Route Tables – Maps

• Route table = the map of each neighborhood.
• Shows where traffic goes: “to the internet → through IGW”, “internal traffic → local route”.

4. Internet Gateway (IGW) – International Border Gate

• IGW = the international border gate connecting the city to the outside world (Internet).
• Only citizens with passports (Public IP/Elastic IP) can pass through.

5. Elastic Network Interface (ENI) – The Door to a House

• ENI = the door of each apartment (instance).
• Each door has a number (IP).
• The door can be detached and attached to another house in the same district (AZ).

6. Interface Endpoint – VIP Tunnel

• Interface Endpoint = a VIP tunnel inside the neighborhood.
• Leads directly to government offices/services (S3, Systems Manager, CloudWatch, SaaS vendors).
• No need to go through the border gate (IGW).
• Protected by its own Security Group.

7. Gateway Endpoint – Special Toll Booth

• Gateway Endpoint = a toll booth inside the city.
• Connects only to two special places: the warehouse (S3) and the marketplace (DynamoDB).
• Uses internal roads, no need to reach the highway.

8. Security Group – Door Guards

• Security Group = guards standing at the door of each house (ENI).
• They decide who can enter/exit.
• Rules are stateful: if entry is allowed, return traffic is automatically allowed.

9. Network ACL (NACL) – Police Checkpoint at Neighborhood Entrance

• NACL = police checkpoint at the entrance of the neighborhood (subnet).
• Inspects everyone going in/out.
• Rules are stateless: if inbound is allowed, outbound must be explicitly allowed too.

10. VPC Flow Logs – Surveillance Cameras

• Flow Logs = traffic cameras installed in the city.
• Record who goes where, and whether it succeeded or was blocked.
• Useful for troubleshooting (traffic jam, illegal intrusion).

11. VPC Peering – Bridge Between Two Cities

• Peering = a bridge connecting two cities.
• Citizens can travel directly between them.
• But only two cities at a time → no central transit (no “hub and spoke”).

12. Transit Gateway – Central Bus Station

• Transit Gateway = the central bus station.
• All cities connect here; to go anywhere, citizens pass through this hub.
• Centralized management, no need to build separate bridges for each pair.

13. VPN Site-to-Site – Secret Tunnel

• VPN = a secret tunnel between CloudCity and your real-world city (on-premises).
• Protected by encryption (IPSec).
• Citizens can travel safely through this tunnel.

14. AWS Direct Connect – Private Highway

• Direct Connect = a private high-speed highway from your company’s headquarters to CloudCity.
• Does not go through the Internet.
• High speed, low latency, stable, no congestion.
• Ideal for enterprises needing large bandwidth and reliability.

15. Elastic Load Balancing (ELB) – Traffic Roundabout

• ELB = a roundabout at an intersection.
• When cars (requests) arrive, the roundabout distributes them evenly across multiple roads (EC2 servers).
• If one road is broken, the roundabout automatically blocks it, preventing cars from entering.

2 Practice labs how to create VPC, EC2, subnets, route tables, security groups, and internet gateways:

-Create VPC -Create Subnet -Create Internet Gateway -Create Route Table -Create Sercurity Groups -Create EC2 -Test Connection EC2 -Connection Private EC2 -Create NAT gateway