Articles & Guides
Useful resources for web developers and system administrators
DNS
DNSSEC: How DNS Security Works and Why You Need It
What is DNSSEC, how it protects against DNS spoofing. Chain of trust, RRSIG, DNSKEY, DS record types. How to check and configure DNSSEC.
Monitoring
Website Uptime and SLA: What 99.9% Really Means
What is website uptime and SLA. The difference between 99.9% and 99.99%, how to calculate allowed downtime, and availability monitoring tools.
HTTP
HTTP/2 vs HTTP/3: Differences and Performance Comparison
Comparing HTTP/2 and HTTP/3 protocols: multiplexing, QUIC, head-of-line blocking, performance. How to check and configure your server.
Security
Open Server Ports: How to Check and Why It Matters for Security
Guide to checking open ports: TCP/UDP, common ports, scanning tools, security risks, and best practices for hardening your server.
Domains
WHOIS: How to Look Up Domain Information and Why It Matters
Complete guide to WHOIS lookups: how to find domain ownership, registration dates, expiry times. Examples, tools, and practical applications.
DNS
DNS Propagation — Why DNS Changes Don't Work Immediately
What is DNS propagation, why DNS changes don't take effect instantly, how to check DNS spread, and how to speed up the process. A practical guide.
Monitoring
Website Monitoring — Why You Need It and How to Set It Up
Complete guide to website monitoring: uptime, SSL, DNS, speed. How to choose check intervals, set up alerts, and never miss a downtime.
Security
Content Security Policy (CSP) — A Complete Configuration Guide
What is Content Security Policy, how to configure the CSP header, which directives to use. Configuration examples and common mistakes.
SSL/TLS
How to Check a Website's SSL Certificate: Step-by-Step Guide
How to check a website's SSL certificate: expiration date, certificate chain, TLS protocols, vulnerabilities. Online tools and command-line methods.
Security
HSTS — What It Is and Why Your Website Needs It
What is HSTS (HTTP Strict Transport Security), how it protects against attacks, how to configure the header, and how to avoid common mistakes. A practical guide.