SSH Troubleshooting

1. There's a connection timeout

This is a security group issue. Any timeout (not just for SSH) is related to security groups or a firewall. Ensure your security group looks like this and correctly assigned to your EC2 instance.

2) There's still a connection timeout issue

If your security group is properly configured as above, and you still have connection timeout issues, then that means a corporate firewall or a personal firewall is blocking the connection. Please use EC2 Instance Connect as described in the next lecture.

3. SSH does not work on Windows

• If it says: ssh command not found, that means you have to use Putty
• Follow again the video. If things don't work, please use EC2 Instance Connect as described in the next lecture

4) There's a connection refused

This means the instance is reachable, but no SSH utility is running on the instance

• Try to restart the instance
• If it doesn't work, terminate the instance and create a new one. Make sure you're using Amazon Linux 2

5)  Permission denied (publickey,gssapi-keyex,gssapi-with-mic)

This means either two things:

• You are using the wrong security key or not using a security key. Please look at your EC2 instance configuration to make sure you have assigned the correct key to it.
• You are using the wrong user. Make sure you have started an Amazon Linux 2 EC2 instance, and make sure you're using the user ec2-user. This is something you specify when doing **ec2-user@**<public-ip> (ex: [email protected]) in your SSH command or your Putty configuration

6. Nothing is working - "aaaahhhhhh"

Don't panic. Use EC2 Instance Connect from the next lecture. Make sure you started an Amazon Linux 2 and you will be able to follow along with the tutorial :)

7) I was able to connect yesterday, but today I can't