Tutorial Series

How To Troubleshoot SSH

SSH is the primary method available for managing DigitalOcean Droplets. Dealing with SSH errors or failures can be frustrating because the errors themselves often prohibit you from accessing your servers. This troubleshooting series covers some of the most common issues you may encounter with SSH, how to address them, when to consider re-deploying, and how to get further support.
  • This tutorial will cover two important prerequisites to troubleshooting your SSH issues. The first is determining whether or not troubleshooting is the right decision, or if migration/redeployment is a more appropriate solution. The second is reviewing the resources and skills necessary to efficiently resolve SSH issues, like having root access to the server and being familiar with file manipulation.
  • When connecting an SSH client to an SSH server, basic network connectivity must be properly established. This tutorial will cover how to identify some common situations that would cause issues at this point in the process, how to resolve those situations, and how to access additional resources to prevent them in the future.
  • This tutorial will cover issues related to protocol initiation. There are a few problems that can occur as the system establishes an encrypted connection with your client. This tutorial will cover how to identify these issues and resolve them, while providing further resources to prevent them in the future.
  • This tutorial covers SSH authentication issues. Once the connection is established and the protocol is initiated to communicate securely, the system can then verify the user connecting to the system. This layer of authentication supports a wide variety of authentication mechanisms, but this walkthrough will cover the two most common: password and private/public keypair.
  • Once your SSH connection is established and you are authenticated, the remote shell environment is then executed. There are a couple of issues that can occur at this point as described below, followed by actions you can take to address them.