# CfnNetworkInterface

Describes a network interface in an Amazon EC2 instance for AWS CloudFormation .

Extends: Construct › CfnElement › CfnRefElement › CfnResource › CfnNetworkInterface
Implements: IInspectable, ITaggable, IEnvironmentAware, INetworkInterfaceRef, IConstruct, IDependable

- CloudFormation: [`AWS::EC2::NetworkInterface`](https://docs.aws.amazon.com/AWSCloudFormation/latest/TemplateReference/aws-resource-ec2-networkinterface.html)
- Source: Generated code
- Type last changed: v2.252.0 · 30 Apr 2026

## Example

```ts
// The code below shows an example of how to instantiate this type.
// The values are placeholders you should change.
import { aws_ec2 as ec2 } from 'aws-cdk-lib';
const cfnNetworkInterface = new ec2.CfnNetworkInterface(this, 'MyCfnNetworkInterface', {
  subnetId: 'subnetId',

  // the properties below are optional
  connectionTrackingSpecification: {
    tcpEstablishedTimeout: 123,
    udpStreamTimeout: 123,
    udpTimeout: 123,
  },
  description: 'description',
  enablePrimaryIpv6: false,
  groupSet: ['groupSet'],
  interfaceType: 'interfaceType',
  ipv4PrefixCount: 123,
  ipv4Prefixes: [{
    ipv4Prefix: 'ipv4Prefix',
  }],
  ipv6AddressCount: 123,
  ipv6Addresses: [{
    ipv6Address: 'ipv6Address',
  }],
  ipv6PrefixCount: 123,
  ipv6Prefixes: [{
    ipv6Prefix: 'ipv6Prefix',
  }],
  privateIpAddress: 'privateIpAddress',
  privateIpAddresses: [{
    primary: false,
    privateIpAddress: 'privateIpAddress',
  }],
  publicIpDnsHostnameTypeSpecification: 'publicIpDnsHostnameTypeSpecification',
  secondaryPrivateIpAddressCount: 123,
  sourceDestCheck: false,
  tags: [{
    key: 'key',
    value: 'value',
  }],
});
```

## Initializer

```ts
new CfnNetworkInterface(scope: Construct, id: string, props: CfnNetworkInterfaceProps)
```

## Construct Props

- `connectionTrackingSpecification`: [IResolvable](/cdk/api/v2/docs/aws-cdk-lib.IResolvable.html) | [CfnNetworkInterface.ConnectionTrackingSpecificationProperty](/cdk/api/v2/docs/aws-cdk-lib.aws_ec2.CfnNetworkInterface.ConnectionTrackingSpecificationProperty.html) — A connection tracking specification for the network interface.

- `description`: string — A description for the network interface.

- `enablePrimaryIpv6`: boolean | [IResolvable](/cdk/api/v2/docs/aws-cdk-lib.IResolvable.html) — If you’re modifying a network interface in a dual-stack or IPv6-only subnet, you have the option to assign a primary IPv6 IP address.

  A primary IPv6 address is an IPv6 GUA address associated with an ENI that you have enabled to use a primary IPv6 address. Use this option if the instance that this ENI will be attached to relies on its IPv6 address not changing. AWS will automatically assign an IPv6 address associated with the ENI attached to your instance to be the primary IPv6 address. Once you enable an IPv6 GUA address to be a primary IPv6, you cannot disable it. When you enable an IPv6 GUA address to be a primary IPv6, the first IPv6 GUA will be made the primary IPv6 address until the instance is terminated or the network interface is detached. If you have multiple IPv6 addresses associated with an ENI attached to your instance and you enable a primary IPv6 address, the first IPv6 GUA address associated with the ENI becomes the primary IPv6 address.

- `groupSet`: string | [ISecurityGroupRef](/cdk/api/v2/docs/aws-cdk-lib.interfaces.aws_ec2.ISecurityGroupRef.html)[] — The IDs of the security groups associated with this network interface.

- `interfaceType`: string — The type of network interface.

  The default is `interface` . The supported values are `efa` and `trunk` .

- `ipv4PrefixCount`: number — The number of IPv4 prefixes to be automatically assigned to the network interface.

  When creating a network interface, you can't specify a count of IPv4 prefixes if you've specified one of the following: specific IPv4 prefixes, specific private IPv4 addresses, or a count of private IPv4 addresses.

- `ipv4Prefixes`: [IResolvable](/cdk/api/v2/docs/aws-cdk-lib.IResolvable.html) | [IResolvable](/cdk/api/v2/docs/aws-cdk-lib.IResolvable.html) | [CfnNetworkInterface.Ipv4PrefixSpecificationProperty](/cdk/api/v2/docs/aws-cdk-lib.aws_ec2.CfnNetworkInterface.Ipv4PrefixSpecificationProperty.html)[] — The IPv4 delegated prefixes that are assigned to the network interface.

  When creating a network interface, you can't specify IPv4 prefixes if you've specified one of the following: a count of IPv4 prefixes, specific private IPv4 addresses, or a count of private IPv4 addresses.

- `ipv6AddressCount`: number — The number of IPv6 addresses to assign to the network interface.

  Amazon EC2 automatically selects the IPv6 addresses from the subnet range. To specify specific IPv6 addresses, use the `Ipv6Addresses` property and don't specify this property.

  When creating a network interface, you can't specify a count of IPv6 addresses if you've specified one of the following: specific IPv6 addresses, specific IPv6 prefixes, or a count of IPv6 prefixes.

- `ipv6Addresses`: [IResolvable](/cdk/api/v2/docs/aws-cdk-lib.IResolvable.html) | [IResolvable](/cdk/api/v2/docs/aws-cdk-lib.IResolvable.html) | [CfnNetworkInterface.InstanceIpv6AddressProperty](/cdk/api/v2/docs/aws-cdk-lib.aws_ec2.CfnNetworkInterface.InstanceIpv6AddressProperty.html)[] — The IPv6 addresses from the IPv6 CIDR block range of your subnet to assign to the network interface.

  If you're specifying a number of IPv6 addresses, use the `Ipv6AddressCount` property and don't specify this property.

  When creating a network interface, you can't specify IPv6 addresses if you've specified one of the following: a count of IPv6 addresses, specific IPv6 prefixes, or a count of IPv6 prefixes.

- `ipv6PrefixCount`: number — The number of IPv6 prefixes to be automatically assigned to the network interface.

  When creating a network interface, you can't specify a count of IPv6 prefixes if you've specified one of the following: specific IPv6 prefixes, specific IPv6 addresses, or a count of IPv6 addresses.

- `ipv6Prefixes`: [IResolvable](/cdk/api/v2/docs/aws-cdk-lib.IResolvable.html) | [IResolvable](/cdk/api/v2/docs/aws-cdk-lib.IResolvable.html) | [CfnNetworkInterface.Ipv6PrefixSpecificationProperty](/cdk/api/v2/docs/aws-cdk-lib.aws_ec2.CfnNetworkInterface.Ipv6PrefixSpecificationProperty.html)[] — The IPv6 delegated prefixes that are assigned to the network interface.

  When creating a network interface, you can't specify IPv6 prefixes if you've specified one of the following: a count of IPv6 prefixes, specific IPv6 addresses, or a count of IPv6 addresses.

- `privateIpAddress`: string — The private IPv4 address to assign to the network interface as the primary private IP address.

  If you want to specify multiple private IP addresses, use the `PrivateIpAddresses` property.

- `privateIpAddresses`: [IResolvable](/cdk/api/v2/docs/aws-cdk-lib.IResolvable.html) | [IResolvable](/cdk/api/v2/docs/aws-cdk-lib.IResolvable.html) | [CfnNetworkInterface.PrivateIpAddressSpecificationProperty](/cdk/api/v2/docs/aws-cdk-lib.aws_ec2.CfnNetworkInterface.PrivateIpAddressSpecificationProperty.html)[] — The private IPv4 addresses to assign to the network interface.

  You can specify a primary private IP address by setting the value of the `Primary` property to `true` in the `PrivateIpAddressSpecification` property. If you want EC2 to automatically assign private IP addresses, use the `SecondaryPrivateIpAddressCount` property and do not specify this property.

  When creating a network interface, you can't specify private IPv4 addresses if you've specified one of the following: a count of private IPv4 addresses, specific IPv4 prefixes, or a count of IPv4 prefixes.

- `publicIpDnsHostnameTypeSpecification`: string — Public IP DNS hostname type.

- `secondaryPrivateIpAddressCount`: number — The number of secondary private IPv4 addresses to assign to a network interface.

  When you specify a number of secondary IPv4 addresses, Amazon EC2 selects these IP addresses within the subnet's IPv4 CIDR range. You can't specify this option and specify more than one private IP address using `privateIpAddresses` .

  When creating a Network Interface, you can't specify a count of private IPv4 addresses if you've specified one of the following: specific private IPv4 addresses, specific IPv4 prefixes, or a count of IPv4 prefixes.

- `sourceDestCheck`: boolean | [IResolvable](/cdk/api/v2/docs/aws-cdk-lib.IResolvable.html) — Enable or disable source/destination checks, which ensure that the instance is either the source or the destination of any traffic that it receives.

  If the value is `true` , source/destination checks are enabled; otherwise, they are disabled. The default value is `true` . You must disable source/destination checks if the instance runs services such as network address translation, routing, or firewalls.

- `subnetId`: string | [ISubnetRef](/cdk/api/v2/docs/aws-cdk-lib.interfaces.aws_ec2.ISubnetRef.html) (required) — The ID of the subnet to associate with the network interface.

- `tags`: [CfnTag](/cdk/api/v2/docs/aws-cdk-lib.CfnTag.html)[] — The tags to apply to the network interface.

## Properties

- `attrId`: string (required) — The ID of the network interface.

- `attrPrimaryIpv6Address`: string (required) — The primary IPv6 address of the network interface.

- `attrPrimaryPrivateIpAddress`: string (required) — The primary private IP address of the network interface.

  For example, `10.0.0.192` .

- `attrPublicIpDnsNameOptions`: [IResolvable](/cdk/api/v2/docs/aws-cdk-lib.IResolvable.html) (required) — Describes the public hostname type options, including public hostname type, IPv4-enabled public hostname, IPv6-enabled public hostname, and dual-stack public hostname.

- `attrSecondaryPrivateIpAddresses`: string[] (required) — The secondary private IP addresses of the network interface.

  For example, `["10.0.0.161", "10.0.0.162", "10.0.0.163"]` .

- `attrVpcId`: string (required) — The ID of the VPC.

- `CFN_RESOURCE_TYPE_NAME`: string (required) (static) — The CloudFormation resource type name for this resource class.

- `cfnOptions`: [ICfnResourceOptions](/cdk/api/v2/docs/aws-cdk-lib.ICfnResourceOptions.html) (required) — Options for this resource, such as condition, update policy etc.

- `cfnResourceType`: string (required) — AWS resource type.

- `connectionTrackingSpecification`: [IResolvable](/cdk/api/v2/docs/aws-cdk-lib.IResolvable.html) | [CfnNetworkInterface.ConnectionTrackingSpecificationProperty](/cdk/api/v2/docs/aws-cdk-lib.aws_ec2.CfnNetworkInterface.ConnectionTrackingSpecificationProperty.html) — A connection tracking specification for the network interface.

- `creationStack`: string[] (required)

- `description`: string — A description for the network interface.

- `enablePrimaryIpv6`: boolean | [IResolvable](/cdk/api/v2/docs/aws-cdk-lib.IResolvable.html) — If you’re modifying a network interface in a dual-stack or IPv6-only subnet, you have the option to assign a primary IPv6 IP address.

- `env`: [ResourceEnvironment](/cdk/api/v2/docs/aws-cdk-lib.interfaces.ResourceEnvironment.html) (required)

- `groupSet`: string[] — The IDs of the security groups associated with this network interface.

- `interfaceType`: string — The type of network interface.

- `ipv4PrefixCount`: number — The number of IPv4 prefixes to be automatically assigned to the network interface.

- `ipv4Prefixes`: [IResolvable](/cdk/api/v2/docs/aws-cdk-lib.IResolvable.html) | [IResolvable](/cdk/api/v2/docs/aws-cdk-lib.IResolvable.html) | [CfnNetworkInterface.Ipv4PrefixSpecificationProperty](/cdk/api/v2/docs/aws-cdk-lib.aws_ec2.CfnNetworkInterface.Ipv4PrefixSpecificationProperty.html)[] — The IPv4 delegated prefixes that are assigned to the network interface.

- `ipv6AddressCount`: number — The number of IPv6 addresses to assign to the network interface.

- `ipv6Addresses`: [IResolvable](/cdk/api/v2/docs/aws-cdk-lib.IResolvable.html) | [IResolvable](/cdk/api/v2/docs/aws-cdk-lib.IResolvable.html) | [CfnNetworkInterface.InstanceIpv6AddressProperty](/cdk/api/v2/docs/aws-cdk-lib.aws_ec2.CfnNetworkInterface.InstanceIpv6AddressProperty.html)[] — The IPv6 addresses from the IPv6 CIDR block range of your subnet to assign to the network interface.

- `ipv6PrefixCount`: number — The number of IPv6 prefixes to be automatically assigned to the network interface.

- `ipv6Prefixes`: [IResolvable](/cdk/api/v2/docs/aws-cdk-lib.IResolvable.html) | [IResolvable](/cdk/api/v2/docs/aws-cdk-lib.IResolvable.html) | [CfnNetworkInterface.Ipv6PrefixSpecificationProperty](/cdk/api/v2/docs/aws-cdk-lib.aws_ec2.CfnNetworkInterface.Ipv6PrefixSpecificationProperty.html)[] — The IPv6 delegated prefixes that are assigned to the network interface.

- `logicalId`: string (required) — The logical ID for this CloudFormation stack element.

  The logical ID of the element
  is calculated from the path of the resource node in the construct tree.

  To override this value, use `overrideLogicalId(newLogicalId)`.

- `networkInterfaceRef`: [NetworkInterfaceReference](/cdk/api/v2/docs/aws-cdk-lib.interfaces.aws_ec2.NetworkInterfaceReference.html) (required) — A reference to a NetworkInterface resource.

- `node`: [Node](/cdk/api/v2/docs/constructs.Node.html) (required) — The tree node.

- `privateIpAddress`: string — The private IPv4 address to assign to the network interface as the primary private IP address.

- `privateIpAddresses`: [IResolvable](/cdk/api/v2/docs/aws-cdk-lib.IResolvable.html) | [IResolvable](/cdk/api/v2/docs/aws-cdk-lib.IResolvable.html) | [CfnNetworkInterface.PrivateIpAddressSpecificationProperty](/cdk/api/v2/docs/aws-cdk-lib.aws_ec2.CfnNetworkInterface.PrivateIpAddressSpecificationProperty.html)[] — The private IPv4 addresses to assign to the network interface.

- `publicIpDnsHostnameTypeSpecification`: string — Public IP DNS hostname type.

- `ref`: string (required) — Return a string that will be resolved to a CloudFormation `{ Ref }` for this element.

  If, by any chance, the intrinsic reference of a resource is not a string, you could
  coerce it to an IResolvable through `Lazy.any({ produce: resource.ref })`.

- `secondaryPrivateIpAddressCount`: number — The number of secondary private IPv4 addresses to assign to a network interface.

- `sourceDestCheck`: boolean | [IResolvable](/cdk/api/v2/docs/aws-cdk-lib.IResolvable.html) — Enable or disable source/destination checks, which ensure that the instance is either the source or the destination of any traffic that it receives.

- `stack`: [Stack](/cdk/api/v2/docs/aws-cdk-lib.Stack.html) (required) — The stack in which this element is defined.

  CfnElements must be defined within a stack scope (directly or indirectly).

- `subnetId`: string (required) — The ID of the subnet to associate with the network interface.

- `tags`: [TagManager](/cdk/api/v2/docs/aws-cdk-lib.TagManager.html) (required) — Tag Manager which manages the tags for this resource.

- `tagsRaw`: [CfnTag](/cdk/api/v2/docs/aws-cdk-lib.CfnTag.html)[] — The tags to apply to the network interface.

## Methods

- `addDeletionOverride(path: string): void` — Syntactic sugar for `addOverride(path, undefined)`.

  **Parameters**

  - `path` — The path of the value to delete.

- `addDependency(target: CfnResource): void` — Use `addResourceDependency` instead.

  This method has been renamed to `addResourceDependency` to more clearly
  set it apart from `construct.node.addDependency`. See the documentation
  of that function for more details.

- `addDependsOn(target: CfnResource): void` — Use `addResourceDependency` instead.

  This can be used for resources across stacks (or nested stack) boundaries
  and the dependency will automatically be transferred to the relevant scope.

  This method has been renamed to `addResourceDependency`, which makes it
  more clear that this method operates at a different level from the
  construct-level `construct.node.addDependency()` mechanism.

- `addMetadata(key: string, value: any): void` — Add a value to the CloudFormation Resource Metadata.

- `addOverride(path: string, value: any): void` — Adds an override to the synthesized CloudFormation resource.

  To add a
  property override, either use `addPropertyOverride` or prefix `path` with
  "Properties." (i.e. `Properties.TopicName`).

  If the override is nested, separate each nested level using a dot (.) in the path parameter.
  If there is an array as part of the nesting, specify the index in the path.

  To include a literal `.` in the property name, prefix with a `\`. In most
  programming languages you will need to write this as `"\\."` because the
  `\` itself will need to be escaped.

  For example,
  ```typescript
  cfnResource.addOverride('Properties.GlobalSecondaryIndexes.0.Projection.NonKeyAttributes', ['myattribute']);
  cfnResource.addOverride('Properties.GlobalSecondaryIndexes.1.ProjectionType', 'INCLUDE');
  ```
  would add the overrides
  ```json
  "Properties": {
    "GlobalSecondaryIndexes": [
      {
        "Projection": {
          "NonKeyAttributes": [ "myattribute" ]
          ...
        }
        ...
      },
      {
        "ProjectionType": "INCLUDE"
        ...
      },
    ]
    ...
  }
  ```

  The `value` argument to `addOverride` will not be processed or translated
  in any way. Pass raw JSON values in here with the correct capitalization
  for CloudFormation. If you pass CDK classes or structs, they will be
  rendered with lowercased key names, and CloudFormation will reject the
  template.

  **Parameters**

  - `path` — - The path of the property, you can use dot notation to override values in complex types.
  - `value` — - The value.

- `addPropertyDeletionOverride(propertyPath: string): void` — Adds an override that deletes the value of a property from the resource definition.

  **Parameters**

  - `propertyPath` — The path to the property.

- `addPropertyOverride(propertyPath: string, value: any): void` — Adds an override to a resource property.

  Syntactic sugar for `addOverride("Properties.<...>", value)`.

  **Parameters**

  - `propertyPath` — The path of the property.
  - `value` — The value.

- `addResourceDependency(target: CfnResource, reason?: string): void` — Indicates that this resource depends on another resource and cannot be provisioned unless the other resource has been successfully provisioned.

  This can be used for resources across stacks (or nested stack) boundaries
  and the dependency will automatically be transferred to the relevant scope.

  This method only adds dependencies between L1 resources. If you are
  looking for a generic construct-to-construct dependency mechanism that works
  for all constructs including L2s, use `construct.node.addDependency` instead.

- `applyCrossStackReferenceStrength(strength: ReferenceStrength): void` — Sets the cross-stack reference strength for this resource.

  When set, any cross-stack reference to this resource will use the specified
  strength instead of the global default from the consuming stack's context.

  **Parameters**

  - `strength` — - The reference strength to use for this resource.

- `applyRemovalPolicy(policy?: RemovalPolicy, options?: RemovalPolicyOptions): void` — Sets the deletion policy of the resource based on the removal policy specified.

  The Removal Policy controls what happens to this resource when it stops
  being managed by CloudFormation, either because you've removed it from the
  CDK application or because you've made a change that requires the resource
  to be replaced.

  The resource can be deleted (`RemovalPolicy.DESTROY`), or left in your AWS
  account for data recovery and cleanup later (`RemovalPolicy.RETAIN`). In some
  cases, a snapshot can be taken of the resource prior to deletion
  (`RemovalPolicy.SNAPSHOT`). A list of resources that support this policy
  can be found in the following link:

- `arnForNetworkInterface(resource: INetworkInterfaceRef): string` (static)

- `cfnPropertyName(cdkPropertyName: string): string`

- `fromNetworkInterfaceId(scope: Construct, id: string, networkInterfaceId: string): INetworkInterfaceRef` (static) — Creates a new INetworkInterfaceRef from a networkInterfaceId.

- `getAtt(attributeName: string, typeHint?: ResolutionTypeHint): Reference` — Returns a token for an runtime attribute of this resource.

  Ideally, use generated attribute accessors (e.g. `resource.arn`), but this can be used for future compatibility
  in case there is no generated attribute.

  **Parameters**

  - `attributeName` — The name of the attribute.

- `getMetadata(key: string): any` — Retrieve a value value from the CloudFormation Resource Metadata.

- `inspect(inspector: TreeInspector): void` — Examines the CloudFormation resource and discloses attributes.

  **Parameters**

  - `inspector` — tree inspector to collect and process attributes.

- `isCfnElement(x: any): boolean` (static) — Returns `true` if a construct is a stack element (i.e. part of the synthesized cloudformation template).

  Uses duck-typing instead of `instanceof` to allow stack elements from different
  versions of this library to be included in the same stack.

  **Returns:** The construct as a stack element or undefined if it is not a stack element.

- `isCfnNetworkInterface(x: any): boolean` (static) — Checks whether the given object is a CfnNetworkInterface.

- `isCfnResource(x: any): boolean` (static) — Check whether the given object is a CfnResource.

- `isConstruct(x: any): boolean` (static) — Checks if `x` is a construct.

  Use this method instead of `instanceof` to properly detect `Construct`
  instances, even when the construct library is symlinked.

  Explanation: in JavaScript, multiple copies of the `constructs` library on
  disk are seen as independent, completely different libraries. As a
  consequence, the class `Construct` in each copy of the `constructs` library
  is seen as a different class, and an instance of one class will not test as
  `instanceof` the other class. `npm install` will not create installations
  like this, but users may manually symlink construct libraries together or
  use a monorepo tool: in those cases, multiple copies of the `constructs`
  library can be accidentally installed, and `instanceof` will behave
  unpredictably. It is safest to avoid using `instanceof`, and using
  this type-testing method instead.

  **Parameters**

  - `x` — Any object.

  **Returns:** true if `x` is an object created from a class which extends `Construct`.

- `obtainDependencies(): Stack | CfnResource[]` — Retrieves an array of resources and stacks this resource depends on.

  For resources depended on directly, returns the `CfnResource` object. For
  dependencies on other stacks, returns the `Stack` object. The order of the
  array is not guaranteed.

- `overrideLogicalId(newLogicalId: string): void` — Overrides the auto-generated logical ID with a specific ID.

  **Parameters**

  - `newLogicalId` — The new logical ID to use for this stack element.

- `removeDependency(target: CfnResource): void` — Use `removeResourceDependency` instead

  This can be used for resources across stacks (including nested stacks)
  and the dependency will automatically be removed from the relevant scope.

- `removeResourceDependency(target: CfnResource): void` — Indicates that this resource no longer depends on another resource.

  This can be used for resources across stacks (including nested stacks)
  and the dependency will automatically be removed from the relevant scope.

- `replaceDependency(target: CfnResource, newTarget: CfnResource): void` — Replaces one dependency with another.

  **Parameters**

  - `target` — The dependency to replace.
  - `newTarget` — The new dependency to add.

- `toString(): string` — Returns a string representation of this construct.

  **Returns:** a string representation of this resource

- `with(...mixins: IMixin[]): IConstruct` — Applies one or more mixins to this construct.

  Mixins are applied in order. The list of constructs is captured at the
  start of the call, so constructs added by a mixin will not be visited.
  Use multiple `with()` calls if subsequent mixins should apply to added
  constructs.