How to fix the error Failed to connect to your instance?

A few points to consider:

• EC2 Instance Connect (EIC) requires installation in your host operating system. Some managed AWS AMIs have Instance Connect pre-installed - namely, Amazon Linux and Ubuntu 20.04 and later. If you are not using one of these operating systems, you will need to install EIC.

• Your instance needs connectivity to AWS EIC service endpoints, either public ones using the internet, or via a private EIC endpoint
• Your users need connectivity to the instance - even if you are connecting via the Console. There are two ways to establish that connectivity - by giving internet access to your instance, or by creating a private connection y using AWS Direct Connect, AWS Site-to-Site VPN, or VPC peering, so that your users can reach the instance's private IP address.
• You need to allow TCP access on port 22 (sounds like you have already done this).
• Every IAM user that you want to connect to your instance via EIC will need appropriate permissions.

The link Chirag posted is a useful reference: https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-instance-connect-prerequisites.html

You can also read more about how the service works - in short, by adding an SSH key temporarily to the instance to allow you to connect, then removing it when your session ends - here: https://aws.amazon.com/blogs/security/use-ec2-instance-connect-to-provide-secure-ssh-access-to-ec2-instances-with-private-ip-addresses/

Hello,

I am assuming this is a new instance. Did you try to check the Routing settings ? From where are you trying to access the instance ? Does it have an internet gateway attached and the routing set correctly. I am assuming NACL/SG settings are correctly set ?

Refer the link below for the pre-requisites required.

Link- https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/connection-prereqs.html