How do EC2 security groups work?

A security group acts as a virtual firewall for your EC2 instances to control incoming and outgoing traffic. Inbound rules control the incoming traffic to your instance, and outbound rules control the outgoing traffic from your instance. When you launch an instance, you can specify one or more security groups.

What is security group rule in AWS?

Security group rules enable you to filter traffic based on protocols and port numbers. Security groups are stateful—if you send a request from your instance, the response traffic for that request is allowed to flow in regardless of inbound security group rules.

How does a security group work?

A security group acts as a virtual firewall for your instance to control inbound and outbound traffic. For each security group, you add rules that control the inbound traffic to instances, and a separate set of rules that control the outbound traffic.

What does security group do?

Security groups are used to collect user accounts, computer accounts, and other groups into manageable units. In the Windows Server operating system, there are several built-in accounts and security groups that are preconfigured with the appropriate rights and permissions to perform specific tasks.

What can security groups be attached to?

Either type of security group can be associated with any other resource, as long as they are in the same network type (classic or VPC)….5 Answers

• Amazon RDS (Relational Database Service)
• Amazon Redshift.
• Amazon ElastiCache.
• Amazon CloudSearch.

How are security groups stateful?

Security groups are stateful—if you send a request from your instance, the response traffic for that request is allowed to flow in regardless of the inbound rules. Your changes are automatically applied to the instances that are associated with the security group.

How do multiple security groups work?

When multiple security groups are applied to an instance, the rules are aggregated to create one large set of rules. In EC2, security group rules are only permissive, in other words, you cannot add any DENY rules. What this means is that the most permissive rule will always apply.

How many security groups are there in an EC2 instance?

five
You can specify one or more security groups for each EC2 instance, with a maximum of five per network interface. Additionally, each instance in a subnet in your VPC can be assigned to a different set of security groups.