# ec2-instance-multiple-eni-check
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Checks if Amazon Elastic Compute Cloud (Amazon EC2) uses multiple Elastic Network Interfaces (ENIs) or Elastic Fabric Adapters (EFAs). The rule is NON\$1COMPLIANT an Amazon EC2 instance use multiple network interfaces. 



**Identifier:** EC2\$1INSTANCE\$1MULTIPLE\$1ENI\$1CHECK

**Resource Types:** AWS::EC2::Instance

**Trigger type:** Configuration changes

**AWS Region:** All supported AWS regions

**Parameters:**

NetworkInterfaceIds (Optional)Type: CSV  
Comma-separated list of network instance IDs

## Proactive Evaluation
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 For steps on how to run this rule in proactive mode, see [Evaluating Your Resources with AWS Config Rules](./evaluating-your-resources.html#evaluating-your-resources-proactive). For this rule to return COMPLIANT in proactive mode, the resource configuration schema for the [StartResourceEvaluation](https://docs.aws.amazon.com/config/latest/APIReference/API_StartResourceEvaluation.html) API needs to include the following inputs, encoded as a string: 

```
"ResourceConfiguration":
...
{
   "NetworkInterfaces": "[NetworkInterfaceId-1, NetworkInterfaceId-2, NetworkInterfaceId-3, ...]"
} 
...
```

 For more information on proactive evaluation, see [Evaluation Mode](./evaluate-config-rules.html). 

## AWS CloudFormation template
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To create AWS Config managed rules with AWS CloudFormation templates, see [Creating AWS Config Managed Rules With AWS CloudFormation Templates](aws-config-managed-rules-cloudformation-templates.md).