A parks department EC2 web server sits behind a security group. What is the foundational inbound behavior of that security group before any custom allow rules are added?
Select an answer to reveal the explanation.
Short Explanation
A security group is a locked front door until you add a key for a specific guest. Inbound starts denied; only the allow rules you write open the path. That default-deny inbound habit is the CLF idea to remember.
Full Explanation
Security groups are stateful virtual firewalls associated with elastic network interfaces. By default they deny inbound traffic and permit outbound traffic unless rules are changed, and only explicitly allowed inbound traffic is accepted. They do not use deny rules in the same way network ACLs do. NACLs operate at the subnet layer and do not replace security groups. Understanding default-deny inbound behavior is foundational security-group awareness.