Unable to delete eni interface lambda type.

Question

Hi,
Unable to delete eni interfaces lambda type. The interface 'in-use'  status, but no lambda function exists
Tried manually by running :
aws ec2 delete-network-interface --network-interface-id

The EC2 instances terminated properly.

Sergey Diner · Accepted Answer

Hi,
Unfortunately the articles above didn't help. Still unable to delete.
I got the message below:

No Lambda functions or versions found that were using the same subnet as this ENI.
If this ENI is not deleted automatically in the next 24 hours then it may be 'stuck'. If the ENI will not allow you to delete it manually after 24 hours then please contact AWS support and send them the output of this script.

In addition there are no Amazon MSK, self-managed Kafka, Amazon MQ, or Amazon DocumentDB services on my account in all regions since this is a new free tier.

re:Post Agent · Answer

This is a common issue when trying to delete network interfaces (ENIs) associated with Lambda functions, even when the Lambda function no longer exists. Here are some steps you can take to resolve this:

1. Wait for automatic deletion: Lambda typically deletes the ENI automatically, but this process can take up to an hour. Try waiting and then attempt to delete the ENI again.

2. Use the Lambda ENI Finder: AWS provides a tool called the Lambda ENI Finder that can help identify which Lambda functions or versions might be using the network interface. Run this tool to check for any associations.

3. Check for old Lambda versions: Sometimes, inactive versions of Lambda functions can still reference the subnets. Go through your Lambda functions in the AWS Console and delete any old versions that might be affected.

4. Verify event source mappings: Check if any event source mappings from services like Amazon MSK, self-managed Kafka, Amazon MQ, or Amazon DocumentDB are using the ENI.

5. Force detach using AWS CLI: You can try to force detach the network interface using the AWS CLI command:
   aws ec2 detach-network-interface --attachment-id <attachment-id> --force
   Note that this may not work for Lambda-managed attachments.

6. Check VPC configuration: If you recently updated a function to remove its VPC configuration, Lambda may require up to 20 minutes to delete the attached Hyperplane ENI.

If none of these steps resolve the issue, it's recommended to contact AWS Support for further assistance, as there could be an underlying issue specific to your account or setup. They can help internally remove the ENIs if necessary.  
**Sources**  
[Want to delete Network Interface, but it is showing it is connected to lambda, but there is no lambda | AWS re:Post](https://repost.aws/questions/QUeubaX6YaSgm8cDEVKcG8DA/want-to-delete-network-interface-but-it-is-showing-it-is-connected-to-lambda-but-there-is-no-lambda)  
[Unable to Delete network interface due link with Lambda | AWS re:Post](https://repost.aws/questions/QUWfi2H-MtTo-M5qjz-_UVNg/unable-to-delete-network-interface-due-link-with-lambda)  
[how do i delete network interface that its type is lambda | AWS re:Post](https://repost.aws/questions/QU7NPrHpvTQGerf8AEsDWKmw/how-do-i-delete-network-interface-that-its-type-is-lambda)

Mikel Del Tio · Answer

Hi,

The following [Knowledge Center article](https://repost.aws/knowledge-center/lambda-eni-find-delete) provides some tips on deleting ENIs created by AWS Lambda functions. Take a look; it might help you.

Unable to delete eni interface lambda type.

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