Instance security requires that you fully understand AWS security groups, along with patching responsibility, key pairs, and various tenancy options.
As a precursor to this post, you should have a thorough understanding of the AWS Shared Responsibility Model before moving onto discussing instance-level security within your Virtual Private Cloud (VPC).
In this article, I’ll talk about AWS security groups and how they can be used to protect your EC2 instances. We’ll also explore applying security patches to your instances and multi-tenancy options. If you want to deploy services and resources within the AWS Cloud, understanding the fundamentals of AWS is critical. To dive into the differences between the compute services, check out my course on AWS Compute Fundamentals. This course is the first step in the AWS Fundamentals Learning Path and covers the fundamental elements of all AWS compute services and features that will allow you to select the most appropriate service for your project and implementations.
AWS security groups and instance security
AWS security groups (SGs) are associated with EC2 instances and provide security at the protocol and port access level. Each security group — working much the same way as a firewall — contains a set of rules that filter traffic coming into and out of an EC2 instance. Unlike network access control lists (NACLs), there are no “Deny” rules. If there is no rule that explicitly permits a particular data packet, it will be dropped.
You should always aim to restrict access with your security group to help maintain restriction of access at the protocol and port level. In addition to this, you should implement the rule of least privilege when it comes to designing and implementing your rules in your security groups. Only allow the access that is needed, and do not apply overly permissive access as this can result in