Final answer:
To make an EC2 instance publicly accessible on the IPv4 internet, it needs an attached Internet Gateway, a Public IPv4 Address on the instance, and the Public IPv4 configured on the OS.
Step-by-step explanation:
To make an Amazon EC2 instance publicly accessible on the IPv4 internet, certain actions are required:
- An attached Internet Gateway: This is necessary to allow communication between the EC2 instance and the internet.
- Public IPv4 Address configured on the instance: The EC2 instance must have a public IP address to be reachable on the internet.
- Public IPv4 configured on the OS: The operating system of the EC2 instance should be configured to use the public IP address assigned to the instance.
A NAT Gateway is not required for a single instance to be publicly accessible; it is used more for instances in private subnets to access the internet without being directly exposed to the internet.