A guide for managing multiple SSH private keys on a single system, useful for accessing different servers or working with Amazon EC2. Shows how to configure the .ssh/config file to specify different identity files, hostnames, users, and ports for each server, enabling easy SSH access by hostname alone.
A guide to setting up remote Git repositories on Linux servers via SSH or on USB flash drives. Covers creating a bare repository with git init --bare, using --shared flag for team projects, pushing to remote repositories, adding remote servers for easier access, and leveraging SSH keys for authentication.
A guide to protecting SSH servers on Linux from brute force attacks. Covers disabling root login, changing SSH ports, using iptables rate limiting rules to temporarily block aggressive IPs, and installing DenyHosts for permanent blocking with optional synchronization to a community blocklist.
A comprehensive guide to using the PF firewall on FreeBSD to block SSH brute force attacks. Covers enabling PF, creating a brute force table with tracking rules, and using pfctl commands to manage blocked IPs, providing automated protection against password guessing attempts.
A guide for creating SFTP-only users on FreeBSD that can transfer files securely but cannot log in via SSH to run commands. Covers creating a dedicated group, configuring sshd_config with chroot and ForceCommand settings, and adding restricted users.
A quick tip for preventing SSH connections from dropping due to inactivity by editing the ssh_config file to send keep-alive packets every 30 seconds, ensuring stable connections on networks with aggressive timeout settings.
An introduction to SSH tunneling techniques for secure data transmission. Covers dynamic port forwarding for web browsing and IM clients, local port forwarding for RDP/VNC access, and reverse tunneling for accessing systems behind firewalls. Includes examples and automation scripts, plus instructions for PuTTY users on Windows.
A comprehensive guide to creating and using SSH keys for secure passwordless authentication. Covers key generation, understanding public-key cryptography, key distribution using authorized_keys, and using PuTTY on Windows to enable secure login and automate file transfers without passwords.