[ aws . ec2 ]

create-subnet

Description

Creates a subnet in a specified VPC.

You must specify an IPv4 CIDR block for the subnet. After you create a subnet, you can’t change its CIDR block. The allowed block size is between a /16 netmask (65,536 IP addresses) and /28 netmask (16 IP addresses). The CIDR block must not overlap with the CIDR block of an existing subnet in the VPC.

If you’ve associated an IPv6 CIDR block with your VPC, you can create a subnet with an IPv6 CIDR block that uses a /64 prefix length.

Warning

Amazon Web Services reserves both the first four and the last IPv4 address in each subnet’s CIDR block. They’re not available for use.

If you add more than one subnet to a VPC, they’re set up in a star topology with a logical router in the middle.

When you stop an instance in a subnet, it retains its private IPv4 address. It’s therefore possible to have a subnet with no running instances (they’re all stopped), but no remaining IP addresses available.

For more information about subnets, see Your VPC and subnets in the Amazon Virtual Private Cloud User Guide .

See also: AWS API Documentation

See ‘aws help’ for descriptions of global parameters.

Synopsis

  create-subnet
[--tag-specifications <value>]
[--availability-zone <value>]
[--availability-zone-id <value>]
[--cidr-block <value>]
[--ipv6-cidr-block <value>]
[--outpost-arn <value>]
--vpc-id <value>
[--dry-run | --no-dry-run]
[--ipv6-native | --no-ipv6-native]
[--cli-input-json | --cli-input-yaml]
[--generate-cli-skeleton <value>]

Options

--tag-specifications (list)

The tags to assign to the subnet.

(structure)

The tags to apply to a resource when the resource is being created.

Note

The Valid Values lists all the resource types that can be tagged. However, the action you’re using might not support tagging all of these resource types. If you try to tag a resource type that is unsupported for the action you’re using, you’ll get an error.

ResourceType -> (string)

The type of resource to tag on creation.

Tags -> (list)

The tags to apply to the resource.

(structure)

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 256 Unicode characters.

Shorthand Syntax:

ResourceType=string,Tags=[{Key=string,Value=string},{Key=string,Value=string}] ...

JSON Syntax:

[
  {
    "ResourceType": "capacity-reservation"|"client-vpn-endpoint"|"customer-gateway"|"carrier-gateway"|"dedicated-host"|"dhcp-options"|"egress-only-internet-gateway"|"elastic-ip"|"elastic-gpu"|"export-image-task"|"export-instance-task"|"fleet"|"fpga-image"|"host-reservation"|"image"|"import-image-task"|"import-snapshot-task"|"instance"|"instance-event-window"|"internet-gateway"|"ipam"|"ipam-pool"|"ipam-scope"|"ipv4pool-ec2"|"ipv6pool-ec2"|"key-pair"|"launch-template"|"local-gateway"|"local-gateway-route-table"|"local-gateway-virtual-interface"|"local-gateway-virtual-interface-group"|"local-gateway-route-table-vpc-association"|"local-gateway-route-table-virtual-interface-group-association"|"natgateway"|"network-acl"|"network-interface"|"network-insights-analysis"|"network-insights-path"|"network-insights-access-scope"|"network-insights-access-scope-analysis"|"placement-group"|"prefix-list"|"replace-root-volume-task"|"reserved-instances"|"route-table"|"security-group"|"security-group-rule"|"snapshot"|"spot-fleet-request"|"spot-instances-request"|"subnet"|"subnet-cidr-reservation"|"traffic-mirror-filter"|"traffic-mirror-session"|"traffic-mirror-target"|"transit-gateway"|"transit-gateway-attachment"|"transit-gateway-connect-peer"|"transit-gateway-multicast-domain"|"transit-gateway-policy-table"|"transit-gateway-route-table"|"transit-gateway-route-table-announcement"|"volume"|"vpc"|"vpc-endpoint"|"vpc-endpoint-service"|"vpc-peering-connection"|"vpn-connection"|"vpn-gateway"|"vpc-flow-log"|"capacity-reservation-fleet"|"traffic-mirror-filter-rule"|"vpc-endpoint-connection-device-type",
    "Tags": [
      {
        "Key": "string",
        "Value": "string"
      }
      ...
    ]
  }
  ...
]

--availability-zone (string)

The Availability Zone or Local Zone for the subnet.

Default: Amazon Web Services selects one for you. If you create more than one subnet in your VPC, we do not necessarily select a different zone for each subnet.

To create a subnet in a Local Zone, set this value to the Local Zone ID, for example us-west-2-lax-1a . For information about the Regions that support Local Zones, see Available Regions in the Amazon Elastic Compute Cloud User Guide .

To create a subnet in an Outpost, set this value to the Availability Zone for the Outpost and specify the Outpost ARN.

--availability-zone-id (string)

The AZ ID or the Local Zone ID of the subnet.

--cidr-block (string)

The IPv4 network range for the subnet, in CIDR notation. For example, 10.0.0.0/24 . We modify the specified CIDR block to its canonical form; for example, if you specify 100.68.0.18/18 , we modify it to 100.68.0.0/18 .

This parameter is not supported for an IPv6 only subnet.

--ipv6-cidr-block (string)

The IPv6 network range for the subnet, in CIDR notation. The subnet size must use a /64 prefix length.

This parameter is required for an IPv6 only subnet.

--outpost-arn (string)

The Amazon Resource Name (ARN) of the Outpost. If you specify an Outpost ARN, you must also specify the Availability Zone of the Outpost subnet.

--vpc-id (string)

The ID of the VPC.

--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 .

--ipv6-native | --no-ipv6-native (boolean)

Indicates whether to create an IPv6 only subnet.

--cli-input-json | --cli-input-yaml (string) Reads arguments from the JSON string provided. The JSON string follows the format provided by --generate-cli-skeleton. If other arguments are provided on the command line, those 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. This may not be specified along with --cli-input-yaml.

--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. Similarly, if provided yaml-input it will print a sample input YAML that can be used with --cli-input-yaml. If provided with the value output, it validates the command inputs and returns a sample output JSON for that command. The generated JSON skeleton is not stable between versions of the AWS CLI and there are no backwards compatibility guarantees in the JSON skeleton generated.

See ‘aws help’ for descriptions of global parameters.

Examples

Note

To use the following examples, you must have the AWS CLI installed and configured. See the Getting started guide in the AWS CLI User Guide for more information.

Unless otherwise stated, all examples have unix-like quotation rules. These examples will need to be adapted to your terminal’s quoting rules. See Using quotation marks with strings in the AWS CLI User Guide .

Example 1: To create a subnet with an IPv4 CIDR block only

The following create-subnet example creates a subnet in the specified VPC with the specified IPv4 CIDR block.

aws ec2 create-subnet \
    --vpc-id vpc-081ec835f3EXAMPLE \
    --cidr-block 10.0.0.0/24 \
    --tag-specifications ResourceType=subnet,Tags=[{Key=Name,Value=my-ipv4-only-subnet}]

Output:

{
    "Subnet": {
        "AvailabilityZone": "us-west-2a",
        "AvailabilityZoneId": "usw2-az2",
        "AvailableIpAddressCount": 251,
        "CidrBlock": "10.0.0.0/24",
        "DefaultForAz": false,
        "MapPublicIpOnLaunch": false,
        "State": "available",
        "SubnetId": "subnet-0e99b93155EXAMPLE",
        "VpcId": "vpc-081ec835f3EXAMPLE",
        "OwnerId": "123456789012",
        "AssignIpv6AddressOnCreation": false,
        "Ipv6CidrBlockAssociationSet": [],
        "Tags": [
            {
                "Key": "Name",
                "Value": "my-ipv4-only-subnet"
            }
        ],
        "SubnetArn": "arn:aws:ec2:us-west-2:123456789012:subnet/subnet-0e99b93155EXAMPLE"
    }
}

Example 2: To create a subnet with both IPv4 and IPv6 CIDR blocks

The following create-subnet example creates a subnet in the specified VPC with the specified IPv4 and IPv6 CIDR blocks.

aws ec2 create-subnet \
    --vpc-id vpc-081ec835f3EXAMPLE \
    --cidr-block 10.0.0.0/24 \
    --ipv6-cidr-block 2600:1f16:cfe:3660::/64 \
    --tag-specifications ResourceType=subnet,Tags=[{Key=Name,Value=my-ipv4-ipv6-subnet}]

Output:

{
    "Subnet": {
        "AvailabilityZone": "us-west-2a",
        "AvailabilityZoneId": "usw2-az2",
        "AvailableIpAddressCount": 251,
        "CidrBlock": "10.0.0.0/24",
        "DefaultForAz": false,
        "MapPublicIpOnLaunch": false,
        "State": "available",
        "SubnetId": "subnet-0736441d38EXAMPLE",
        "VpcId": "vpc-081ec835f3EXAMPLE",
        "OwnerId": "123456789012",
        "AssignIpv6AddressOnCreation": false,
        "Ipv6CidrBlockAssociationSet": [
            {
                "AssociationId": "subnet-cidr-assoc-06c5f904499fcc623",
                "Ipv6CidrBlock": "2600:1f13:cfe:3660::/64",
                "Ipv6CidrBlockState": {
                    "State": "associating"
                }
            }
        ],
        "Tags": [
            {
                "Key": "Name",
                "Value": "my-ipv4-ipv6-subnet"
            }
        ],
        "SubnetArn": "arn:aws:ec2:us-west-2:123456789012:subnet/subnet-0736441d38EXAMPLE"
    }
}

Example 3: To create a subnet with an IPv6 CIDR block only

The following create-subnet example creates a subnet in the specified VPC with the specified IPv6 CIDR block.

aws ec2 create-subnet \
    --vpc-id vpc-081ec835f3EXAMPLE \
    --ipv6-native \
    --ipv6-cidr-block 2600:1f16:115:200::/64 \
    --tag-specifications ResourceType=subnet,Tags=[{Key=Name,Value=my-ipv6-only-subnet}]

Output:

{
    "Subnet": {
        "AvailabilityZone": "us-west-2a",
        "AvailabilityZoneId": "usw2-az2",
        "AvailableIpAddressCount": 0,
        "DefaultForAz": false,
        "MapPublicIpOnLaunch": false,
        "State": "available",
        "SubnetId": "subnet-03f720e7deEXAMPLE",
        "VpcId": "vpc-081ec835f3EXAMPLE",
        "OwnerId": "123456789012",
        "AssignIpv6AddressOnCreation": true,
        "Ipv6CidrBlockAssociationSet": [
            {
                "AssociationId": "subnet-cidr-assoc-01ef639edde556709",
                "Ipv6CidrBlock": "2600:1f13:cfe:3660::/64",
                "Ipv6CidrBlockState": {
                    "State": "associating"
                }
            }
        ],
        "Tags": [
            {
                "Key": "Name",
                "Value": "my-ipv6-only-subnet"
            }
        ],
        "SubnetArn": "arn:aws:ec2:us-west-2:123456789012:subnet/subnet-03f720e7deEXAMPLE"
    }
}

For more information, see VPCs and subnets in the Amazon VPC User Guide.

Output

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.

EnableLniAtDeviceIndex -> (integer)

Indicates the device position for local network interfaces in this subnet. For example, 1 indicates local network interfaces in this subnet are the secondary network interface (eth1).

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.

(structure)

Describes an association between a subnet and an IPv6 CIDR block.

AssociationId -> (string)

The ID of the association.

Ipv6CidrBlock -> (string)

The IPv6 CIDR block.

Ipv6CidrBlockState -> (structure)

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.

(structure)

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 256 Unicode characters.

SubnetArn -> (string)

The Amazon Resource Name (ARN) of the subnet.

OutpostArn -> (string)

The Amazon Resource Name (ARN) of the Outpost.

EnableDns64 -> (boolean)

Indicates whether DNS queries made to the Amazon-provided DNS Resolver in this subnet should return synthetic IPv6 addresses for IPv4-only destinations.

Ipv6Native -> (boolean)

Indicates whether this is an IPv6 only subnet.

PrivateDnsNameOptionsOnLaunch -> (structure)

The type of hostnames to assign to instances in the subnet at launch. An instance hostname is based on the IPv4 address or ID of the instance.

HostnameType -> (string)

The type of hostname for EC2 instances. For IPv4 only subnets, an instance DNS name must be based on the instance IPv4 address. For IPv6 only subnets, an instance DNS name must be based on the instance ID. For dual-stack subnets, you can specify whether DNS names use the instance IPv4 address or the instance ID.

EnableResourceNameDnsARecord -> (boolean)

Indicates whether to respond to DNS queries for instance hostnames with DNS A records.

EnableResourceNameDnsAAAARecord -> (boolean)

Indicates whether to respond to DNS queries for instance hostname with DNS AAAA records.