How to create subnets in 3 AZs of ap-northeast-2 region ?

[jgcman3]

Hello,

It seems that it is not possible to create subnets in all multiple Availability Zones.

• region : ap-northeast-2
• AZs : ap-northeast-2a, ap-northeast-2b, ap-northeast-2c

Please refer to the below my cdk code.

    this.vpc_vpc_main = new ec2.Vpc(this, "vpc-vpc-main", {
      cidr: "10.137.0.0/16",
      maxAzs: 3,
      natGateways: 1,
      subnetConfiguration: [
        {
          name: "vpc-subnet-main",
          subnetType: ec2.SubnetType.PUBLIC,
          cidrMask: 20,
        },
        {
          name: "vpc-subnet-instance",
          subnetType: ec2.SubnetType.PRIVATE,
          cidrMask: 20,
        },
        {
          name: "vpc-subnet-rds",
          subnetType: ec2.SubnetType.ISOLATED,
          cidrMask: 20,
        },
        {
          name: "vpc-subnet-lambda",
          subnetType: ec2.SubnetType.PRIVATE,
          cidrMask: 20,
        },
      ],
    });

I expected that 4 subnets would be created in each of the 3 Availability Zones.
However, no subnet was created in the ap-northeast-2c available zone.

For reference, the reason I'm trying to create subnets in the 2c availability zone is that ap-northeast-2a and ap-northeast-2c are required for the subnet group required when creating aurora serverless.

Any idea to create subnets in ap-northeast-2c available zone ?

Thanks

[nathan-boulestin]

If you want to use all AZs of a region set maxAzs to a highter number than the number of AZs in the region. So you can set maxAzs to 99 for exemple

[jgcman3]

Thanks for your reply.
I tried to do with maxAzs to 99.
But no subnet was created in the ap-northeast-2c available zone.
Is the result of the action different from me?

[nathan-boulestin]

Isn't your stack environment-agnostic ? See the doc here

I just tried it worked well for me

[jgcman3]

You are right :)

I didn't set the account and region on the stack.

Thanks!

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