Frequently asked questions for SSH
In this section we collect all frequently asked questions about SSH. Do you have a question or one that really should be listed here? Share your feedback. Thanks for your contribution!
How to add a SSH key to the SSH agent
Learn how to load and use your SSH key together with a SSH agent. This frequently asked question will explain the usage of ssh-add and ssh-agent.
How to disable the SSH host key check?
OpenSSH performs a host authenticity check when connecting to a system. Learn how to disable the check with the SSH option StrictHostKeyChecking.
How to disable the usage of the SSH agent
The SSH agent can be used to simplify authentication. As that is not always preferred behavior, we can disable the SSH agent when authenticating.
How to remove the passphrase from a SSH key
While protecting SSH keys is typically advised, it is not always feasible in automated processes. Learn how to remove the password or passphrase from a SSH key.
How to see the available SSH keys in the OpenSSH authentication agent
The SSH agent can load stored SSH keys into memory for authentication purposes. Use the ss-add command to show the available SSH keys that are loaded.
How to see the SSH log?
SSH logs authentication attempts, but where? Find your SSH log file with these tips, such as in /var/log/auth.log or in the systemd journal.
How to start the SSH agent?
The OpenSSH agent helps with authentication by making SSH keys available. Learn how to start the SSH agent when it is not running on your Linux system.
How to terminate a SSH connection that does not respond to CTRL+C
Learn about SSH escape sequences and how they can help with terminating a SSH connection that does not respond to CTRL+C.
How to test the sshd configuration for configuration errors?
A healthy service should not have configuration issues. Perform a configuration test of the SSH daemon (sshd) by first running it using the '-t' option.
What is SSH agent forwarding?
The agent forwarding feature in SSH allows using your local SSH agent to be reached through an existing SSH connection. Learn when and how to use it.
What is the purpose of the SSH agent?
The SSH agent is a helper utility to temporarily store private keys when using public key authentication. Learn more about how this helps during daily tasks.