Do AWS security rules make changes to IPtables?

Question

I am curious to know how AWS security rules will be applied to host. After assigning AWS security rules, how the traffic flow is controlled. Is it via IP table updates?

For testing, I added the security groups to an instance but I don't see any iptable updates.

Thank you in advance

Answer 1

When you make a change to security groups, no changes occur on the EC2 instance(s).

Security groups act like a firewall external to your EC2 instances. So connections are blocked before they reach your EC2 instances.