AWS SDK Version 3 for .NET
API Reference

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Container for the parameters to the CreateSubnet operation. Creates a subnet in an existing VPC.

When you create each subnet, you provide the VPC ID and IPv4 CIDR block for the subnet. After you create a subnet, you can't change its CIDR block. The size of the subnet's IPv4 CIDR block can be the same as a VPC's IPv4 CIDR block, or a subset of a VPC's IPv4 CIDR block. If you create more than one subnet in a VPC, the subnets' CIDR blocks must not overlap. The smallest IPv4 subnet (and VPC) you can create uses a /28 netmask (16 IPv4 addresses), and the largest uses a /16 netmask (65,536 IPv4 addresses).

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.

AWS 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.

If you launch an instance in a VPC using an Amazon EBS-backed AMI, the IP address doesn't change if you stop and restart the instance (unlike a similar instance launched outside a VPC, which gets a new IP address when restarted). 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.

Inheritance Hierarchy


Namespace: Amazon.EC2.Model
Assembly: AWSSDK.EC2.dll
Version: 3.x.y.z


public class CreateSubnetRequest : AmazonEC2Request

The CreateSubnetRequest type exposes the following members


Public Method CreateSubnetRequest()

Empty constructor used to set properties independently even when a simple constructor is available

Public Method CreateSubnetRequest(string, string)

Instantiates CreateSubnetRequest with the parameterized properties


Public Property AvailabilityZone System.String

Gets and sets the property AvailabilityZone.

The Availability Zone for the subnet.

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

Public Property CidrBlock System.String

Gets and sets the property CidrBlock.

The IPv4 network range for the subnet, in CIDR notation. For example,

Public Property Ipv6CidrBlock System.String

Gets and sets the property Ipv6CidrBlock.

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

Public Property VpcId System.String

Gets and sets the property VpcId.

The ID of the VPC.


This example creates a subnet in the specified VPC with the specified CIDR block. We recommend that you let us select an Availability Zone for you.

To create a subnet

var response = client.CreateSubnet(new CreateSubnetRequest 
    CidrBlock = "",
    VpcId = "vpc-a01106c2"

Subnet subnet = response.Subnet;


Version Information

.NET Standard:
Supported in: 1.3

.NET Framework:
Supported in: 4.5, 4.0, 3.5

Portable Class Library:
Supported in: Windows Store Apps
Supported in: Windows Phone 8.1
Supported in: Xamarin Android
Supported in: Xamarin iOS (Unified)
Supported in: Xamarin.Forms