Openssh articles

Last change: 2025-01-06

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.

Last change: 2025-01-06

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.

Last change: 2025-01-06

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.

Last change: 2025-01-06

Learn about the SSH client option ProxyJump, that allows using a bastion host or jump server to connect to other systems.

Last change: 2025-01-06

Secure SSH connections and learn about the ForwardAgent option, the available values, relevant security risks, and how to configure it.

Last change: 2025-01-06

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.

Last change: 2025-01-06

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.

Last change: 2025-01-06

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.

Last change: 2025-01-06

The SSH agent can be used to simplify authentication. As that is not always preferred behavior, we can disable the SSH agent when authenticating.

Last change: 2025-01-06

OpenSSH can be configured to use an alternative SSH agent, or even none. Learn about the IdentityAgent option, available values, and how to configure it.

Last change: 2025-01-06

OpenSSH can be configured on the server and client. Learn about the locations where SSH client settings are configured and what precedence they take.

Last change: 2025-01-06

Secure your OpenSSH configuration and learn about the StrictHostKeyChecking option, available values, and how to configure it.

Last change: 2025-01-06

Secure SSH connections and learn about the PasswordAuthentication option, its available values, and how to configure it.

Last change: 2025-01-06

OpenSSH performs a host authenticity check when connecting to a system. Learn how to disable the check with the SSH option StrictHostKeyChecking.

Last change: 2025-01-06

Learn how to make changes to your SSH configuration to have it running on a different port. Change it from port 22 to something like 2222.

Last change: 2025-01-06

Configure a welcome message or banner for users to see before or after logging in via SSH. Here are the instructions to change the relevant configuration files.

Last change: 2025-01-06

OpenSSH has escape sequences available to initiate special commands during an active SSH session. Learn about the available escape sequences with this overview.

Last change: 2025-01-06

Learn about SSH escape sequences and how they can help with terminating a SSH connection that does not respond to CTRL+C.

Last change: 2025-01-06

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.

Last change: 2025-01-06

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.

Last change: 2025-01-06

Linux systems are usually managed remotely with SSH, often still using passwords. Time to switch over to SSH keys and here is how to do that.