How To Change Security Group Ec2

How To Articles

Changing the security group of an EC2 instance is a fundamental task for any AWS user. As someone who has worked extensively with EC2 instances, I can confidently say that understanding how to change the security group is crucial for maintaining a secure and well-managed infrastructure.

Why Change the Security Group of an EC2 Instance?

Before we dive into the details of how to change a security group for an EC2 instance, let’s first understand why it’s important to do so. In AWS, a security group acts as a virtual firewall that controls the inbound and outbound traffic for an EC2 instance. By default, every EC2 instance is associated with a default security group, which allows all inbound traffic from the same security group but denies all other inbound traffic by default. However, in most cases, the default security group is not sufficient to meet the specific requirements of an application, which is why it’s necessary to change it.

Step-by-Step Guide to Changing the Security Group of an EC2 Instance

Now, let’s get into the nitty-gritty details of how to change the security group of an EC2 instance. Follow these steps:

  1. Login to the AWS Management Console and navigate to the EC2 Dashboard.
  2. Select the EC2 instance for which you want to change the security group.
  3. In the “Description” tab, locate the “Security Groups” section and click on the security group associated with the instance.
  4. In the security group details page, click on the “Actions” button and select “Edit inbound rules.”
  5. Review the existing inbound rules and make the necessary changes. You can add new rules, remove existing rules, or modify the rules as per your requirements.
  6. Once you are done with the changes, click on the “Save rules” button to apply the changes.
  7. Finally, verify that the new security group rules are successfully applied by testing the connectivity to the EC2 instance.

That’s it! You have successfully changed the security group of your EC2 instance.

Considerations and Best Practices

While changing the security group of an EC2 instance, it’s essential to keep a few considerations and best practices in mind:

  • Plan and Document: Before making any changes, thoroughly plan and document the desired security group rules to ensure that the process goes smoothly.
  • Least Privilege Principle: Follow the principle of least privilege and only allow the necessary inbound and outbound traffic to minimize the attack surface.
  • Regular Review: Regularly review and update the security group rules to adapt to the changing requirements of your application.
  • Tagging: Use descriptive tags for your security groups to easily identify their purpose and associated resources.


Changing the security group of an EC2 instance is a critical task for maintaining a secure and well-managed AWS infrastructure. By following the step-by-step guide and considering the best practices, you can ensure that your EC2 instances have the necessary security measures in place to protect your applications and data.