I’m running a dockerized Flask web server on an AWS EC2 instance and encountering issues with security group configurations. My goal is to restrict access to only my device/network, but I’m facing difficulties.

Current situation:

• When inbound rule is set to 0.0.0.0/0, I can access the endpoint from anywhere and SSH into the instance.

• I want to restrict access to only my device/network.

Only allowing 0.0.0.0/0 works, but this is not secure.

Questions:

1. How can I correctly configure the security group to allow access only from my specific IP/network?

2. Why aren’t the methods I’ve tried working?

3. Is there a way to troubleshoot this issue or verify if my IP is correct?

What I’ve tried (none of these work):

1. Using my device’s IPv4 address in CIDR format as the inbound rule

2. Using my public IP address in CIDR format

3. Using the “My IP” option in the security group configuration menu

With these configurations, I can’t access:

• The Flask web server endpoint

• The EC2 instance via SSH

Any help or guidance would be greatly appreciated. Thanks!