# ApplicationListenerAttributes

Properties to reference an existing listener.

- Source: [`aws-elasticloadbalancingv2/lib/alb/application-listener.ts`](https://github.com/aws/aws-cdk/blob/v2.274.0/packages/aws-cdk-lib/aws-elasticloadbalancingv2/lib/alb/application-listener.ts#L696)
- Type last changed: v2.42.0 · 16 Sep 2022

## 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';
import { aws_elasticloadbalancingv2 as elbv2 } from 'aws-cdk-lib';

declare const securityGroup: ec2.SecurityGroup;
const applicationListenerAttributes: elbv2.ApplicationListenerAttributes = {
  listenerArn: 'listenerArn',
  securityGroup: securityGroup,

  // the properties below are optional
  defaultPort: 123,
};
```

## Properties

- `defaultPort`: number — The default port on which this listener is listening.

- `listenerArn`: string (required) — ARN of the listener.

- `securityGroup`: [ISecurityGroup](/cdk/api/v2/docs/aws-cdk-lib.aws_ec2.ISecurityGroup.html) (required) — Security group of the load balancer this listener is associated with.