Troubleshooting
Real fixes for common problems: connection errors, boot issues, slow servers, email delivery and website errors.
- Fix SSH connection problems: refused, timed out, denied Each SSH error points to a different layer: the network, the SSH service or the login. Find your message below and follow the fix. Beginner 12 min
- Fix Remote Desktop connection problems on Windows servers Find the Remote Desktop message you see, check the port, credentials and sessions, and get back to your Windows server. Beginner 10 min
- Server unreachable? A step-by-step diagnosis When nothing responds, work from the outside in: is it everyone or just you, is the service active, is the server running, and what does its log say. Beginner 10 min
- Locked out after a firewall change: how to get back in A firewall rule or a port change can cut your own connection. Use the console to undo it, then apply firewall changes with a safety net. Intermediate 10 min
- Disk full: find what fills it and free space safely A full disk stops databases, websites and even SSH logins. Find what uses the space, free it safely and stop it from filling up again. Beginner 12 min
- High CPU or memory usage: find the cause and fix it A slow server is busy with something. Find out what, decide whether to fix the software or give it more resources, and confirm the result. Intermediate 15 min
- Fix 502 Bad Gateway, 503 and 504 errors on your website These errors mean the web server is up but the application behind it is not answering correctly. The logs tell you why within minutes. Intermediate 15 min
- Domain not resolving? Diagnose DNS step by step Follow the DNS chain from the registry to your nameservers to your computer, and the broken link shows itself. Intermediate 12 min
- Emails going to spam? Fix SPF, DKIM, DMARC and reverse DNS Receiving servers decide in seconds whether to trust your mail. These checks show what they see and how to fix each gap. Intermediate 15 min