https://www.udemy.com/aws-certified-solutions-architect-associate/learn/v4/t/lecture/2801686?start=0

Build your own VPC

Create the VPC

• Networking > VPC > Your VPCs > Create VPC
  • Name Tag
  • CIDR = Classless Inter-Domain Routing
• It does NOT automatically create
  • Subnets
  • Internet Gateways
• It DOES automatically create
  • Route Table
  • Network ACL
  • Security Group

Create Subnets

• Subnets CANNOT span AZ!
• AWS reserves 3 IP addresses per subnet, not including the Network Address (.0) or the Broadcast IP (.255)
• By default, all new Subnets will be added to the Main Route Table.
  • The Main Route Table is defaulted to Local only and is not Internet accessible… this is a good thing.
• Recommended Naming convention:
  • NE.TW.OR.K – us-region-#a
• Enable Auto-Assign IPs if this is for public facing instances.

Create Internet Gateway

• Internet Gateways > Create Internet Gateway
• Attach to VPC > Select the VPC to attach it to.
  • You cannot attach multiple Internet Gateways to a VPC.

Create Route Table

• By default, all subnets within a VPC will be able to talk to each other.
• To Create a Public Route
  • Create the Route Table on the desired VPC
  • [Routes Tab] > [Edit]
    • Destination: 0.0.0.0/0
    • Target: Defaults to your Internet Gateway
  • [Subnet Associations Tab] > Edit
    • Select the Subnets you want to allow the Public Access