Practical guides on network security, DNS, SSL, and web infrastructure. Written for developers, sysadmins, and anyone who wants to understand how the internet works.
Transparent methodology for the Website Health Check — severity model, modules, and what we intentionally skip.
Playbook when a site move breaks mail — MX, SPF, DKIM, DMARC, PTR, and TTL convergence.
How HTTPS encryption works, certificate types, and why every website needs SSL.
The Domain Name System explained — record types, resolution, caching, and security.
Step-by-step domain audit guide — or use the free Website Health Check for an automated report.
Checklist before going live — SSL, DNS, email, robots.txt, and security headers.
Understand priority issues, findings, and action items from the Website Health Check.
Essential DNS, MX, SPF, and certificate checks for small business websites.
What to verify after moving to a new host, CDN, or DNS provider.
Common HSTS, CSP, and X-Frame-Options errors — and how to fix them.
Types, uses, security risks, and how to discover all subdomains for a domain.
Request and response headers explained, including security headers every site needs.
How port scanning works, common ports, and legitimate uses for security auditing.
How IP-to-location mapping works, accuracy limits, and real-world use cases.
15-point security audit checklist for website owners and developers.
Domain registration records explained — ownership data, privacy, status codes, and security research uses.
Why DNS changes take time, how TTL works, caching layers, and how to speed up global updates.
The future of web transport — how QUIC replaces TCP, 0-RTT connections, and what it means for performance.
Content Security Policy from basics to nonces and hashes — your strongest defense against XSS.
How DNS-based email authentication prevents spoofing and phishing — with a step-by-step DMARC rollout plan.
SPF, DKIM, DMARC overview, email spoofing prevention, and how to check your email auth.