Possible reasons for timeout when trying to access EC2 instance

Question

I cannot SSH into my instance - Operation timed out. What could be the reasons why, and what can I do to resolve it? Rebooting normally takes a long time to take effect, and might just make things worst. And It is not about permissions, I can log in normally. I suspect it might be because of memory issues.

Answer 1

Check whether you have set an appropriate security group for the instance which allows access from your network to port 22 on the given EC2 instance.

If everything is fine, there may be an issue in that particular instance. So, try launching another instance and doing the same.