connection via AWS ec2 instance connect (ssh) failed - not sure if account issue

Question

Hi,

First post as I'm tearing my hair out. I was connect to my instance fine via about method, but all of a sudden it now stopped. The message I get is "Failed to connect to your instance
EC2 Instance Connect is unable to connect to your instance. Ensure your instance network settings are configured correctly for EC2 Instance Connect. For more information, see EC2 Instance Connect Prerequisites at https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-instance-connect-prerequisites.html.".

I've made sure that the instance has inbound SSH setup in both security group and acl. I've even tried setting up a new instance with a fresh security group (again enabling SSH access) but this still doesn't work.

I'm just wondering if my account has been  'isolated'

Answer

Your EC2 instance can be isolated in a case the instance was identified in a security breach role or part of any vulnerability attack, but you will be notified in your health dashboard and via Email from EC2 Abuse.
Does your instance have Public IP? If it doesn't, then you will have to create Connect Endpoint in the same VPC.
Does the Security group allow SSH from anywhere (0.0.0.0/0) or you are using specific IP range?

To identify the address range, download the JSON file provided by AWS and filter for the subset for EC2 Instance Connect, using EC2_INSTANCE_CONNECT as the service value. These IP address ranges differ between AWS Regions. For more information about downloading the JSON file and filtering by service, see AWS IP address ranges in the Amazon VPC User Guide.

connection via AWS ec2 instance connect (ssh) failed - not sure if account issue

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