Troubleshooting
Common SSH issues including connection refused, permission denied, and timeout problems
SSH Port Conflicts: How to Identify and Change Ports
Resolve frustrating SSH connection issues caused by port conflicts. This guide details how to definitively identify the active SSH port using system commands (`ss`/`netstat`) and provides a step-by-step, safe methodology for modifying the configuration file (`sshd_config`) and updating firewalls to switch to a new port number, preventing lockouts.
Diagnosing and Resolving SSH Authentication Failures
Struggling with SSH authentication failures? This comprehensive guide provides step-by-step instructions for diagnosing and resolving common issues. Learn to effectively use client-side verbose mode (`ssh -vvv`) to understand connection attempts and interpret server-side logs (`/var/log/auth.log` or `/var/log/secure`) for definitive error identification. We cover common pitfalls like incorrect permissions, misconfigured public keys, and server settings, offering actionable solutions to restore your secure remote access quickly and efficiently.
Best Practices for Preventing SSH Timeout Problems
Stop frustrating SSH session drops by implementing robust keep-alive configurations. This essential guide details the difference between client-side (`ServerAliveInterval`) and server-side (`ClientAliveInterval`) configurations, providing step-by-step instructions for tweaking your `~/.ssh/config` file. Learn how to use practical values to bypass aggressive firewall and NAT timeouts, ensuring stable, persistent connectivity even on unstable networks. Also includes recommendations for utilizing multiplexers like `tmux` for ultimate session resilience.
Troubleshooting SSH Permission Denied Publickey Issues
Encountering 'Permission Denied (publickey)' when using SSH? This guide provides a comprehensive walkthrough to resolve this common authentication error. Learn how to meticulously verify SSH key pairs, diagnose incorrect file permissions on both client and server, and ensure your `authorized_keys` file is configured correctly. With practical examples and step-by-step instructions, you'll regain secure access to your remote systems.
Fixing SSH Connection Refused Errors Quickly
Encountering an SSH "Connection Refused" error can halt your remote server management. This comprehensive guide details step-by-step troubleshooting, focusing on critical server-side diagnostics. Learn to verify your SSH daemon's status, check and configure firewall rules (UFW, firewalld), inspect `sshd_config` settings, and utilize basic network connectivity tests. Practical commands and actionable advice are provided to quickly resolve the issue and restore secure access to your systems, ensuring you're back in control swiftly.