Ssh

SSH usage, key management, config files, tunneling, and hardening.

Aug 21, 2026 • 6 min read • series

How to Generate SSH Keys on Linux with ssh-keygen

Generate an SSH key pair on Linux with ssh-keygen, choose between Ed25519 and RSA, and install the public key on a server, a Git host, or a cloud provider.

Aug 21, 2026 • 6 min read

Initial Server Setup on Ubuntu 26.04

Prepare a new Ubuntu 26.04 server with a sudo user, SSH key authentication, UFW firewall rules, a hostname, timezone settings, and system updates.

Aug 21, 2026 • 9 min read • series

How to Set Up Passwordless SSH Login

Set up passwordless SSH login with Ed25519 or RSA key pairs. Copy public keys with ssh-copy-id, use the ssh-agent, and disable password authentication for hardened access.

Aug 6, 2026 • 13 min read • series

sftp Command in Linux: Transfer Files Securely

The sftp command transfers files securely over SSH. Connect to servers, upload and download files, resume transfers, and automate batch jobs.

Jul 27, 2026 • 12 min read • series

SSH Tunnel: Local, Remote, and Dynamic Port Forwarding

Set up SSH tunnels with the -L, -R, and -D options for local, remote, and dynamic port forwarding, with working examples for Linux, macOS, and Windows.

Jul 27, 2026 • 12 min read • series

ssh Command in Linux: Connect to Remote Servers

The ssh command connects you to a remote Linux server. This guide covers its syntax, the most useful options, key-based login, and port forwarding.

Using the ssh command to connect to a remote Linux server

Jul 23, 2026 • 8 min read • series

SSH Connection Refused: Causes and Fixes

Fix the SSH "Connection refused" error by checking the destination, listening port, OpenSSH service or socket, firewall rules, and port forwarding.

SSH connection stopped before reaching port 22 on a Linux server

Jun 29, 2026 • 6 min read

Fix SSH "Host Key Verification Failed" Error

Resolve the SSH Host key verification failed error by removing the stale known_hosts entry with ssh-keygen -R after verifying the server is genuine.

Fixing the SSH Host key verification failed error in known_hosts

Jun 16, 2026 • 7 min read • series

The ~/.ssh Folder: Files, Permissions, and Layout

What lives inside ~/.ssh on Linux: private keys, authorized_keys, known_hosts, config, and the recommended permissions for each file.

The contents and permissions of the ~/.ssh folder on Linux

Jun 10, 2026 • 7 min read

How to Connect to MySQL through SSH Tunnel

Securely connect to a remote MySQL or MariaDB server over an SSH tunnel with local port forwarding, with steps for Linux, macOS, and Windows (PuTTY).

May 11, 2026 • 6 min read • series

SSH SOCKS Proxy: Create a SOCKS5 Tunnel for Browsing

Create an SSH SOCKS proxy with a SOCKS5 tunnel, configure Firefox or Chrome to use it, proxy DNS requests, and verify the browser exits through your SSH server.

Set up SSH SOCKS Tunnel for Private Browsing

May 9, 2026 • 5 min read • series

ssh-copy-id Command: Copy SSH Keys to a Remote Server

How to use the ssh-copy-id command to copy your SSH public key to a remote server and set up passwordless login. Covers options, a manual fallback, and common errors.

May 9, 2026 • 6 min read • series

SSH Permission Denied (publickey): Causes and Fixes

How to troubleshoot the SSH "Permission denied (publickey)" error in Linux. Covers file permissions, missing keys, SELinux, SSH agent issues, and server-side debugging.

May 6, 2026 • 8 min read • series

SSH Hardening Guide: Best Practices for Linux Servers

SSH hardening best practices for Linux servers, including sshd_config checks, key-only logins, root login restrictions, firewall rules, timeouts, and Fail2Ban.

Apr 24, 2026 • 7 min read • series

scp Command in Linux: Secure File Transfer Examples

SCP copies files securely between local and remote hosts over SSH. This guide covers syntax, common options, and practical examples for everyday file transfers.

Use SCP Command to Securely Transfer Files

Apr 22, 2026 • 5 min read • series

How to Enable SSH on Raspberry Pi

Enable SSH on Raspberry Pi with Raspberry Pi Imager, the headless ssh file method, raspi-config, or systemctl. Updated for current Raspberry Pi OS releases.

Apr 16, 2026 • 5 min read • series

How to Change the SSH Port in Linux

Change the default SSH port 22 by editing sshd_config, adjusting the firewall, and reloading the SSH service on Linux.

Change the SSH port in the sshd_config file on Linux

Mar 18, 2026 • 6 min read • series

How to Use SSHFS to Mount Remote Directories over SSH

SSHFS lets you mount a remote directory over SSH and browse it like a local filesystem. This guide covers installation on Linux, macOS, and Windows, mounting with options, persistent fstab mounts, and troubleshooting.

Terminal using SSHFS to mount a remote directory over SSH

Mar 13, 2026 • 6 min read • series

How to Enable SSH on Ubuntu

Enable SSH on Ubuntu by installing OpenSSH Server, starting the ssh service, allowing it through UFW, and connecting remotely from Linux, macOS, or Windows.

Mar 11, 2026 • 8 min read • series

Using the SSH Config File

Set up the SSH client config file to manage multiple remote connections with custom hostnames, users, ports, keys, and jump hosts — all without long command-line flags.