Create Subnet
Create Subnet
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In the VPC Interface:
- Select Subnets
- Select Create subnet
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In the Create subnet Interface:
- Select ASG VPC
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Implement Subnet Settings:
- Subnet name: Enter
Public Subnet 1 - Select AZ ap-southeast-1a
- IPv4 CIDR block: Import
10.10.1.0/24according to the architecture description - Select Create subnet
- Subnet name: Enter
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Finish Creating Subnet
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Follow the same steps to create more subnets:
- Public subnet 2 with CIDR of
10.10.2.0/24located in Availability Zone ap-southeast-1b
- Private subnet 1 with CIDR of
10.10.3.0/24located in Availability Zone ap-southeast-1a
- Private subnet 2 with CIDR of
10.10.4.0/24located in Availability Zone ap-southeast-1b
- Public subnet 2 with CIDR of
Note: You can see there are 2 columns: Availability Zone and Availability Zone ID. To avoid uneven usage of EC2 resources (for example, using AZ a for primary and AZ b for standby), AWS randomly assigns Availability Zone into Availability Zone ID. Availability Zone is an alias, and Availability Zone ID is the identifier. For instance, in the image above, Availability Zone ap-southeast-1a is assigned the Availability Zone ID apse1-az2. In another AWS account, Availability Zone ap-southeast-1a may have an Availability Zone ID of apse1-az1.
Allow Automatic Allocation of Public IP Addresses for 2 Public Subnets
Tip: Another important point to note is that even though the subnets are the same, configuring the routing table and allocating a public IP address allows us to distinguish between Public and Private Subnets.
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In the VPC Interface:
- Select Subnets
- Select Public Subnet 1
- Select Actions
- Select Edit subnet settings
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Under Auto-assign IP settings:
- Select Enable auto-assign public IPv4 address
- Select Save
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Repeat the same process for Public subnet 2.
