Why is it important to configure IAM roles for EC2 instances?

Configuring IAM roles for EC2 instances is critical because it allows for the secure granting of permissions to the instances without the need to store access keys on the instances themselves. IAM (Identity and Access Management) roles provide a way to manage temporary credentials that EC2 instances can use to access AWS services and resources. This enhances security because IAM roles are assigned with specific policies that define permissions, thus ensuring that instances only have access to resources necessary for their operation.

Using IAM roles eliminates the risk associated with hardcoding credentials within your applications. Instead, when an EC2 instance is launched with an associated IAM role, the instance can automatically retrieve temporary credentials from the instance metadata, which are rotated automatically. This implementation adheres to the principle of least privilege, granting the minimum access necessary to perform the required tasks while maintaining a robust security posture.

In contrast, other options relate to functionalities that do not pertain to the specific purpose of IAM roles. For instance, applying firewall rules per instance refers to security groups which govern network access, while managing instance types pertains to the configuration of compute resources, and monitoring network traffic relates to tools like AWS CloudWatch or VPC Flow Logs. None of these directly address the role of IAM in securing access permissions.