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, an

Answer 1

To enable ssh access from the Internet for instances in a VPC subnet do the following:

• Attach an Internet gateway to your VPC.
• Ensure that your subnet's route table points to the Internet gateway.
• Ensure that instances in your subnet have a globally unique IP address (public IPv4 address, Elastic IP address, or IPv6 address).
• Ensure that your network access control (at VPC Level) and security group rules (at ec2 level) allow the relevant traffic to flow to and from your instance. Ensure your network Public IP address is enabled for both. By default, Network AcL allow all inbound and outbound traffic except explicitly configured otherwise