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What are Security Groups in AWS?

AWS (Amazon Web Services) security groups are virtual firewalls that dictate traffic for your EC2 (elastic compute cloud) instances. They provide security at the port and protocol level, acting as the first layer of defense against malicious attackers. AWS security groups function in the same manner as firewalls, but with more advanced capabilities. They contain a set of rules that filter both incoming and outgoing traffic for an EC2 instance, which gives additional security for your business.

AWS is a handy platform with a range of IT resources for organizations to build their workloads in the cloud. To help users secure their instances, AWS provides security groups to allow users to control network traffic in and out of their instances (or servers). You can configure security groups in a way that meets your security needs.

How Do AWS Security Groups Function? 

When you create an EC2 instance in your Virtual Private Cloud (VPC), AWS automatically assigns a default security group to the instance. These default security groups are flexible, and you can customize them according to your security demands. Also, you can create new security groups with your specific rules and assign them to your instances.

AWS Security Groups Rules

Rules control the inbound traffic that can reach a security group and the outbound traffic that can leave. These rules enable users to filter traffic based on port and protocol numbers,which give your business more security. When creating security groups, you need to assign them a name and a description depending on the ruleset.

How to Create AWS Security Groups

You can create Security Groups through the AWS Management Console or the AWS Command Line Interface (AWS CLI).

For each security group, it’s essential to specify these requirements:

  • Group name: not more than 255 security characters
  • Type of rule: HTTP, RDP, SSH
  • Port range: port range or a specific port
  • Source IP (for inbound rules): Subnet range or specific IP address allowed to access
  • Destination (for outbound rules): IP range or a specific IP referring to the destination where outbound traffic is allowed to go
  • Protocols: Specify TCP/UD ports or custom ICMP or entirely custom protocols

Using Multiple Security Groups for EC2 Instances

It’s possible to associate EC2 instances with more than one security group. While you can associate a single instance with numerous security groups, it’s not advisable, as it could cause access problems. If you associate a single EC2 instance with multiple security groups, AWS automatically aggregates these rules to create a single set. It is best to condense your rules as much as possible.

What is the Difference Between AWS Security Groups and Network Access Control Lists (NACLs)

Security groups and Network Access Control Lists (NACLs) are both handy methods of securing AWS. Both security groups and NACLs act as virtual firewalls and use inbound and outbound rules to control traffic.

However, the main difference is that NACLs operate at different layers. NACLs apply at the subnet level while security groups are applied at instance level. The NACLs filter traffic for all instances in a subnet, while security groups control traffic for specific instances.

The Bottom Line

nOps enhances visibility into the organization’s security posture. With nOps, you can audit security groups using the Firewall Manager tool to identify vulnerabilities in your security groups and enhance your overall security groups. In today’s Wild West internet atmosphere, you need as much security for your business as you can get. 

Use nOps security groups audits today to enhance your security and compliance!

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