Table Of Contents


User Guide

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[ aws . ec2 ]



Creates a default subnet with a size /20 IPv4 CIDR block in the specified Availability Zone in your default VPC. You can have only one default subnet per Availability Zone. For more information, see Creating a default subnet in the Amazon Virtual Private Cloud User Guide .

See also: AWS API Documentation

See 'aws help' for descriptions of global parameters.


--availability-zone <value>
[--dry-run | --no-dry-run]
[--cli-input-json <value>]
[--generate-cli-skeleton <value>]


--availability-zone (string)

The Availability Zone in which to create the default subnet.

--dry-run | --no-dry-run (boolean)

Checks whether you have the required permissions for the action, without actually making the request, and provides an error response. If you have the required permissions, the error response is DryRunOperation . Otherwise, it is UnauthorizedOperation .

--cli-input-json (string) Performs service operation based on the JSON string provided. The JSON string follows the format provided by --generate-cli-skeleton. If other arguments are provided on the command line, the CLI values will override the JSON-provided values. It is not possible to pass arbitrary binary values using a JSON-provided value as the string will be taken literally.

--generate-cli-skeleton (string) Prints a JSON skeleton to standard output without sending an API request. If provided with no value or the value input, prints a sample input JSON that can be used as an argument for --cli-input-json. If provided with the value output, it validates the command inputs and returns a sample output JSON for that command.

See 'aws help' for descriptions of global parameters.


To create a default subnet

This example creates a default subnet in Availability Zone us-east-2a.


 aws ec2 create-default-subnet --availability-zone us-east-2a

   "Subnet": {
       "AvailabilityZone": "us-east-2a",
       "Tags": [],
       "AvailableIpAddressCount": 4091,
       "DefaultForAz": true,
       "Ipv6CidrBlockAssociationSet": [],
       "VpcId": "vpc-1a2b3c4d",
       "State": "available",
       "MapPublicIpOnLaunch": true,
       "SubnetId": "subnet-1122aabb",
       "CidrBlock": "",
       "AssignIpv6AddressOnCreation": false


Subnet -> (structure)

Information about the subnet.

AvailabilityZone -> (string)

The Availability Zone of the subnet.

AvailabilityZoneId -> (string)

The AZ ID of the subnet.

AvailableIpAddressCount -> (integer)

The number of unused private IPv4 addresses in the subnet. The IPv4 addresses for any stopped instances are considered unavailable.

CidrBlock -> (string)

The IPv4 CIDR block assigned to the subnet.

DefaultForAz -> (boolean)

Indicates whether this is the default subnet for the Availability Zone.

MapPublicIpOnLaunch -> (boolean)

Indicates whether instances launched in this subnet receive a public IPv4 address.

MapCustomerOwnedIpOnLaunch -> (boolean)

Indicates whether a network interface created in this subnet (including a network interface created by RunInstances ) receives a customer-owned IPv4 address.

CustomerOwnedIpv4Pool -> (string)

The customer-owned IPv4 address pool associated with the subnet.

State -> (string)

The current state of the subnet.

SubnetId -> (string)

The ID of the subnet.

VpcId -> (string)

The ID of the VPC the subnet is in.

OwnerId -> (string)

The ID of the Amazon Web Services account that owns the subnet.

AssignIpv6AddressOnCreation -> (boolean)

Indicates whether a network interface created in this subnet (including a network interface created by RunInstances ) receives an IPv6 address.

Ipv6CidrBlockAssociationSet -> (list)

Information about the IPv6 CIDR blocks associated with the subnet.


Describes an IPv6 CIDR block associated with a subnet.

AssociationId -> (string)

The association ID for the CIDR block.

Ipv6CidrBlock -> (string)

The IPv6 CIDR block.

Ipv6CidrBlockState -> (structure)

Information about the state of the CIDR block.

State -> (string)

The state of a CIDR block.

StatusMessage -> (string)

A message about the status of the CIDR block, if applicable.

Tags -> (list)

Any tags assigned to the subnet.


Describes a tag.

Key -> (string)

The key of the tag.

Constraints: Tag keys are case-sensitive and accept a maximum of 127 Unicode characters. May not begin with aws: .

Value -> (string)

The value of the tag.

Constraints: Tag values are case-sensitive and accept a maximum of 255 Unicode characters.

SubnetArn -> (string)

The Amazon Resource Name (ARN) of the subnet.

OutpostArn -> (string)

The Amazon Resource Name (ARN) of the Outpost.