Articles & Guides
Useful resources for web developers and system administrators
DNS
What Is a DNS Server: Types, How to Find Yours and Fix It
What a DNS server is: how recursive, authoritative, root and TLD servers differ, how to find the one you use, change it, and fix it when it stops responding.
DNS
MX Records for Email: Step-by-Step Setup Guide
Full MX records setup for Google Workspace, Yandex 360, Zoho. Priority, RFC 5321, SPF/DKIM/DMARC, and delivery testing.
DNS
CNAME vs A Record: Differences and When to Use Each
CNAME or A record? Detailed comparison: performance, RFC 1034/1912 constraints, apex domain, CDN, and when each one is the right choice.
DNS
How to Flush DNS Cache: Windows, Mac, Linux, Browsers
Five DNS caches sit between you and an answer, and flushing one leaves four untouched. The copy actually serving you is usually the one you cannot flush.
DNS
How to Check DNS Propagation: 5 Tools and Methods
Check DNS propagation in 2026: 5 best tools, how propagation actually works, dig/nslookup commands, and how to speed it up.
DNS
DNS Not Resolving: 8 Causes and How to Fix
DNS not resolving and the site is down? Learn 8 common causes — from TTL and cache to NS and firewall — with step-by-step diagnostics and tools.
HTTP
HTTP Cache-Control Headers: Complete Caching Guide
Cache-Control complete guide — max-age, no-store, stale-while-revalidate, public/private, real nginx/Apache setup for static, HTML, API.
HTTP
HTTP Redirect Chains and Their Impact on SEO
Redirect chains hurt SEO equity, slow loading, and waste crawl budget. How to find and eliminate 301/302 chains with tools and code examples.
HTTP
504 Gateway Timeout Fix: nginx, WordPress, AWS, Cloudflare
504 Gateway Timeout means a proxy gave up waiting for the backend. Find which hop timed out, read nginx logs, fix slow queries, and tune timeouts safely.
HTTP
HTTP 502 Bad Gateway: What It Means and How to Fix
502 Bad Gateway decoded for nginx/Apache + PHP-FPM/Node.js, how it differs from 500/504, 7 causes, step-by-step fixes with config examples.