Unable to ssh to an instance in AWS

Are you trying to connecto to the private or public IP?

I understand your frustration with being unable to SSH into your AWS EC2 instance. While it's possible that there could be an account-level issue, there are several other factors we should consider first before assuming it's an isolated account state.

Here are some key things to check:

1. Security Group Configuration: You mentioned setting your security groups to allow all traffic, which is a good troubleshooting step. Make sure the inbound rules specifically allow SSH (port 22) from your IP address or 0.0.0.0/0 for testing purposes.

2. Network Configuration: Ensure that your instance is in a public subnet with a route to an Internet Gateway. Check that the instance has a public IP address assigned to it.

3. Instance Status: Verify that the instance is in a "running" state and hasn't been accidentally terminated or stopped.

4. Key Pair: Confirm you're using the correct private key (.pem file) that corresponds to the key pair associated with the instance when it was launched.

5. Permissions on Key File: If you're getting a "Bad owner or permissions" error, ensure your key file has the correct permissions (chmod 400 for the .pem file).

6. Network ACLs: If you're using a custom VPC, check that the Network ACLs allow inbound and outbound SSH traffic.

7. Route Table: Verify that the route table associated with your subnet has a route to the internet gateway (0.0.0.0/0).

8. Instance OS: Ensure you're using the correct username for SSH based on the AMI you've chosen (e.g., ec2-user for Amazon Linux, ubuntu for Ubuntu instances).

If you've checked all these items and are still unable to connect, it might be worth trying to create a new instance in the same VPC and subnet to see if the issue persists.

Regarding the possibility of an account issue, while it's not common, there are rare cases where accounts can be placed in a restricted state due to billing or other administrative reasons. If you've exhausted all other troubleshooting steps, contacting AWS Support would be the next appropriate action. They can investigate if there are any account-level restrictions preventing you from accessing your instances.

Remember, for security best practices, once you resolve the issue, make sure to tighten your security group rules to only allow SSH access from specific IP addresses rather than leaving it open to all traffic.

Sources
instances not connecting via ssh | AWS re:Post
Cannot SSH into AWS EC2 | AWS re:Post
Why can't I connect via SSH to my EC2 instance? | AWS re:Post
Unable to Connect to AWS EC2 Instance via SSH Using RSA Key | AWS re:Post