Work with Amazon VPC > Preparatory steps > Create Subnet

Create Subnet

Create subnet

In VPC interface

Select Subnets
Select Create subnet

Create VPC

In the Create subnet interface

Select ASG VPC

Create VPC

Implement subnet settings

Subnet name, enter Public Subnet 1
Select AZ ap-southeast-1a
IPv4 CIDR block, import 10.10.1.0/24 according to architecture description
Select Create subnet

Create VPC

Finish creating subnet

Create VPC

Follow the same steps to create more subnets

Public subnet 2 with CIDR of 10.10.2.0/24 located in Availability Zone ap-southeast-1b.
Private subnet 1 with CIDR of 10.10.3.0/24 located in Availability Zone ap-southeast-1a.
Private subnet 2 with CIDR of 10.10.4.0/24 located in Availability Zone ap-southeast-1b

Create VPC

You can see there is 2 columns Availability Zone and Availability Zone ID. To avoid EC2 resources being used unevenly, (we tend to use AZ a to run primary and AZ b to stand by for example) AWS will randomly assign * Availability Zone into Availability Zone ID*. We can understand that Availability Zone is a form of alias, and Availability Zone ID is the identifier. For example, in the image above, Availability Zone ap-southeast-1a is assigned the Availability Zone ID apse1-az2. In another AWS account, the Availability Zone ap-southeast-1a may have an Availability Zone ID of apse1-az1.

Allows automatic allocation of public IP addresses for 2 public subnets.

Another point worth noting is that the subnets are the same, through configuring the routeing table and allocating the public IP address that we have divided into Public and Private Subnet.

In the VPC interface

Select Subnets
Select Public Subnet 1
Select Actions
Select Edit subnet settings

Create VPC

In the Auto-assign IP settings section

Select Enable auto-assign public IPv4 address
Select Save
Then do the same with Public subnet 2.

Create VPC