Day 09 - VPC Connectivity & Load Balancing

Date: 2025-09-18 (Thursday)
Status: “Done”

Lecture Notes

VPC Peering & Transit Gateway

VPC Peering

  • Enables direct, private connectivity between two VPCs without traversing the Internet.
  • Does not support transitive routing or overlapping CIDRs.

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VPC Peering Limitations:

  • No transitive peering
  • No overlapping CIDR blocks
  • Limited to 125 peering connections per VPC
  • Cross-region peering supported

AWS Transit Gateway (TGW)

  • Acts as a hub to connect multiple VPCs and on-prem networks, simplifying complex mesh topologies.
  • TGW Attachments associate subnets in specific AZs with a TGW.
  • All subnets within the same AZ can reach the TGW once attached.

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Transit Gateway Benefits:

  • Centralized connectivity hub
  • Simplified network architecture
  • Scalable to thousands of VPCs
  • Supports inter-region peering

VPN & Direct Connect

Site-to-Site VPN

  • Establishes a secure IPSec connection between an on-premises data center and AWS VPC.
  • Consists of:
    • Virtual Private Gateway (VGW): AWS-managed, multi-AZ endpoints.
    • Customer Gateway (CGW): Customer-managed device or software appliance.

AWS Direct Connect

  • Provides a dedicated private network connection between an on-prem data center and AWS.
  • Typical latency: 20–30 ms.
  • In Vietnam, available through Hosted Connections (via partners).
  • Bandwidth is adjustable.

Hands-On Labs

Lab 10 – Hybrid DNS (Route 53 Resolver)

  1. Generate Key Pair → 10-02.1
  2. Initialize CloudFormation Template → 10-02.2
  3. Configure Security Group → 10-02.3
  4. Set up DNS System → 10-05
  5. Create Route 53 Outbound Endpoint → 10-05.1
  6. Create Resolver Rules → 10-05.2
  7. Create Inbound Endpoints → 10-05.3

Lab 19 – VPC Peering

  1. Initialize CloudFormation Templates → 19-02.1
  2. Create Security Group → 19-02.2
  3. Create EC2 Instance (Test Peering) → 19-02.3
  4. Create Peering Connection → 19-04
  5. Configure Route Tables (Cross-VPC) → 19-05
  6. Enable Cross-Peer DNS → 19-06