在AWS Cloud CIDR模板中动态创建CIDR

Question

下面是我的用于创建私有网络和subnets.The私有网络的云形成模板正在成功创建，但子网的创建失败。我尝试给出了我的特定IP范围，但失败了，并出现错误'The CIDR '172.31.48.0/20‘is invalid’如何使用JSON在模板中动态创建各自的CIDRBlock？

"VPC1": {
      "Type": "AWS::EC2::VPC",
      "Properties": {
        "CidrBlock": "10.10.0.0/16",
        "InstanceTenancy": "default",
        "EnableDnsSupport": "true",
        "EnableDnsHostnames": "false",
        "Tags": [
          {
            "Key": "Name",
            "Value": "My Dashboard"
          }
        ]
      }
    },
    "subnet1": {
      "Type": "AWS::EC2::Subnet",
      "Properties": {
        "CidrBlock": "172.31.48.0/20",
        "AvailabilityZone": "us-east-2a",
        "VpcId": {
          "Ref": "VPC1"
        }
      }          
    },
    "subnet2": {
      "Type": "AWS::EC2::Subnet",
      "Properties": {
        "CidrBlock": "172.31.0.0/20",
        "AvailabilityZone": "us-east-2b",
        "VpcId": {
          "Ref": "VPC1"
        },
        "Tags": [
          {
            "Key": "Name",
            "Value": "MyDashboard"
          }
        ]
      }
    },
    "subnet3": {
      "Type": "AWS::EC2::Subnet",
      "Properties": {
        "CidrBlock": "172.31.32.0/20",
        "AvailabilityZone": "us-east-2a",
        "VpcId": {
          "Ref": "VPC1"
        }
      }
    }

私有网络创建成功，但子网创建不成功。我尝试给出了自己的具体网段，但是失败了，错误为'The CIDR '172.31.48.0/20' is invalid'如何使用JSON在模板中动态创建各自的CIDRBlock？

Answer 1

子网应与vpc处于同一网络中。尝试10.10.1.0/24、10.10.2.0/24和10.10.3.0/24对子网有效。

在这里得到了答案：https://forums.aws.amazon.com/thread.jspa?messageID=756147#756147