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
DNS TTL Best Practices: Optimal Values for Different Records
DNS TTL best practices: optimal values for A, MX, NS, TXT. How TTL affects migrations, failover, and load on your authoritative DNS.
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
Complete guide to flushing DNS cache — commands for Windows, macOS, Linux, Chrome, Firefox, Safari. When you need it and why it may not work.
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
HTTP 504 Gateway Timeout: Causes and Solutions for Sysadmins
HTTP 504 Gateway Timeout — 6 causes, difference from 502, proper timeout tuning in nginx/Apache/PHP-FPM/Node.js with real config examples.