Kubernetes CrashLoopBackOff: Causes and How to Fix It
What CrashLoopBackOff means, the common reasons a pod keeps restarting, and a step-by-step way to diagnose and fix the crash loop with kubectl.
Kubernetes ImagePullBackOff and ErrImagePull: How to Fix
What ImagePullBackOff and ErrImagePull mean, why Kubernetes can't pull your container image, and how to diagnose and fix the most common causes.
Kubernetes OOMKilled (Exit Code 137): Causes and Fixes
Why Kubernetes kills pods with OOMKilled and exit code 137, how memory requests and limits cause it, and how to diagnose and fix out-of-memory restarts.
Connection Refused vs Reset vs Timed Out: What They Mean
Connection refused, reset, and timed out mean very different things. What each error reveals about where a failure is, and how to monitor and debug them.
Traceroute Explained: Diagnosing Network Path Problems
How traceroute works, how to read its output, why hops time out, and how to use it with ping and MTR to find where latency and packet loss happen.
Docker Container Unhealthy: How to Debug Health Checks
Why a Docker container shows 'unhealthy', how to read HEALTHCHECK logs, debug docker-compose health checks, and fix the most common causes fast.
Website Down Checker: How to Check If Your Website Is Down & Fix It
Is your website down or just down for you? Use a website down checker to verify real outages, rule out local DNS/cache issues, and fix common downtime causes in minutes.
How to Check if a Port Is Open (Windows, macOS & Linux)
Check if a port is open with telnet, netcat (nc), nmap, PowerShell Test-NetConnection and /dev/tcp on any OS — plus how to monitor ports continuously.
5xx Server Errors Explained: 500, 502, 503, 504 Fix Guide
Diagnose and fix HTTP 5xx server errors. What 500, 502, 503, 504 and Cloudflare 520-526 mean, common causes per code, and how to monitor each.
Is My Website Down? How to Check From Outside in 60 Seconds
Find out if your website is really down or only down for you. Step-by-step external checks: DNS, ping, multi-region, third-party tools, and what to do next.