# NetworkAcl

Define a new custom network ACL.

By default, will deny all inbound and outbound traffic unless entries are
added explicitly allowing it.

Extends: Construct › Resource › NetworkAcl
Implements: IResource, INetworkAcl, IEnvironmentAware, INetworkAclRef, IConstruct, IDependable

- CloudFormation: [`AWS::EC2::NetworkAcl`](https://docs.aws.amazon.com/AWSCloudFormation/latest/TemplateReference/aws-resource-ec2-networkacl.html)
- L1 type: [`CfnNetworkAcl`](/cdk/api/v2/docs/aws-cdk-lib.aws_ec2.CfnNetworkAcl.html)
- Source: [`aws-ec2/lib/network-acl.ts`](https://github.com/aws/aws-cdk/blob/v2.275.0/packages/aws-cdk-lib/aws-ec2/lib/network-acl.ts#L105)
- Type last changed: v2.224.0 · 13 Nov 2025

## 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';

declare const subnet: ec2.Subnet;
declare const subnetFilter: ec2.SubnetFilter;
declare const vpc: ec2.Vpc;
const networkAcl = new ec2.NetworkAcl(this, 'MyNetworkAcl', {
  vpc: vpc,

  // the properties below are optional
  networkAclName: 'networkAclName',
  subnetSelection: {
    availabilityZones: ['availabilityZones'],
    onePerAz: false,
    subnetFilters: [subnetFilter],
    subnetGroupName: 'subnetGroupName',
    subnets: [subnet],
    subnetType: ec2.SubnetType.PRIVATE_ISOLATED,
  },
});
```

## Initializer

```ts
new NetworkAcl(scope: Construct, id: string, props: NetworkAclProps)
```

## Construct Props

- `networkAclName`: string — The name of the NetworkAcl.

  **Default:** CDK generated name

  Since the NetworkAcl resource doesn't support providing a physical name, the value provided here will be recorded in the `Name` tag.

- `subnetSelection`: [SubnetSelection](/cdk/api/v2/docs/aws-cdk-lib.aws_ec2.SubnetSelection.html) — Subnets in the given VPC to associate the ACL with.

  **Default:** No subnets associated

  More subnets can always be added later by calling
  `associateWithSubnets()`.

- `vpc`: [IVpc](/cdk/api/v2/docs/aws-cdk-lib.aws_ec2.IVpc.html) (required) — The VPC in which to create the NetworkACL.

## Properties

- `env`: [ResourceEnvironment](/cdk/api/v2/docs/aws-cdk-lib.interfaces.ResourceEnvironment.html) — The environment this resource belongs to.

  For resources that are created and managed in a Stack (those created by
  creating new class instances like `new Role()`, `new Bucket()`, etc.), this
  is always the same as the environment of the stack they belong to.

  For referenced resources (those obtained from referencing methods like
  `Role.fromRoleArn()`, `Bucket.fromBucketName()`, etc.), they might be
  different than the stack they were imported into.

- `networkAclId`: string — The ID of the NetworkACL.

- `networkAclRef`: [NetworkAclReference](/cdk/api/v2/docs/aws-cdk-lib.interfaces.aws_ec2.NetworkAclReference.html) — A reference to a NetworkAcl resource.

- `networkAclVpcId`: string — The VPC ID for this NetworkACL.

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

- `PROPERTY_INJECTION_ID`: string (static) — Uniquely identifies this class.

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

## Methods

- `addEntry(id: string, options: CommonNetworkAclEntryOptions): NetworkAclEntry` — Add a new entry to the ACL.

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

  When set, any cross-stack reference to this resource will use the specified
  mechanism instead of the global default determined by the
  `@aws-cdk/core:defaultCrossStackReferences` context key. This is useful for
  selectively weakening specific references to avoid the "deadly embrace" problem
  without changing the app-wide default.

  **Parameters**

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

- `applyRemovalPolicy(policy: RemovalPolicy): void` — Apply the given removal policy to this resource.

  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`).

- `associateWithSubnet(id: string, selection: SubnetSelection): void` — Associate the ACL with a given set of subnets.

- `fromNetworkAclId(scope: Construct, id: string, networkAclId: string): INetworkAcl` (static) — Import an existing NetworkAcl into this app.

- `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`.

- `isOwnedResource(construct: IConstruct): boolean` (static) — Returns true if the construct was created by CDK, and false otherwise.

- `isResource(construct: IConstruct): boolean` (static) — Check whether the given construct is a Resource.

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

- `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.