EC2 instances should not use multiple ENIs

ec2

Description

This check verifies if an EC2 instance is using multiple Elastic Network Interfaces (ENIs). If necessary, you can suppress these findings for EC2 instances that require multiple ENIs as part of an Amazon EKS cluster.

Having multiple ENIs can create dual-homed instances, which are instances connected to multiple subnets. This setup can increase network security complexity and introduce unintended network paths and access.

Remediation

For instructions on detaching a network interface from an EC2 instance, refer to the Amazon EC2 User Guide for Linux Instances.