I've been trying to connect to my EC2 instance but I can't seem to get in—even through the AWS UI. I have the private keys on my machine and I've set the network settings to allow TCP traffic on port 22. This issue just started yesterday, as I was able to connect without a hitch before. Any advice would be greatly appreciated!
5 Answers
There could be a lot of reasons for this, even a full disk. Check the Monitor and troubleshoot section for system logs and the instance screenshot—it can give you some clues about what's wrong.
Don't forget that for SSH through the console, you have to allow inbound traffic from all IPv4 to port 22. Just remember to remove that inbound rule after you’re done!
Make sure you've gone through the EC2 troubleshooting steps. They walk you through what to check when you're having connection issues.
If you're using public SSH access (port 22), it's risky without limiting ingress to a static CIDR or individual IP. Your server could get hit with DDoS attacks really fast. I recommend using Session Manager instead. If you're going to try that, consider launching a new t4g.micro instance with an AL2023 AMI, as it has the right setup. Just make sure that your instance's IAM role has the correct SSM policy and you have either a NAT Gateway or all necessary VPC endpoints set up. Security groups should also permit egress on port 443. Once everything's configured correctly, you should be able to connect in a few minutes via the UI Console.
Did you perhaps stop your instance at any point? If you haven't assigned an Elastic IP, your public IP might have changed. That could be why you're unable to connect.
I didn't stop it exactly, just rebooted. But if the public IP has changed, shouldn't I still be able to connect via the AWS UI?