Troubleshoot Boot and Networking Issues with New EC2 Serial Console | AWS News Blog

This is extremely useful for those times when the system is unable to get to the stage where sshd is running, or there are network-related issues which prevent a normal ssh connection from working. This is akin to the console view of a VM through the hypervisor.

… EC2 Serial Console, a simple and secure way to troubleshoot boot and network connectivity issues by establishing a serial connection to your Amazon Elastic Compute Cloud (EC2) instances.