DNS records: A, AAAA, CNAME, MX, TXT — complete reference
A reference guide to DNS records: types, purposes, and examples. A, AAAA, CNAME, MX, TXT, NS, SOA, SRV. Configuring a domain for a website and email.
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Articles, instructions and practical examples about Security.
30 articles in Security
A reference guide to DNS records: types, purposes, and examples. A, AAAA, CNAME, MX, TXT, NS, SOA, SRV. Configuring a domain for a website and email.
Check the domain expiration date, auto-renewal, and grace period. What to do when a domain expires and how to avoid losing it. Regular monitoring.
A complete guide to email deliverability: sender reputation, SPF/DKIM/DMARC authentication, content, blacklists, and monitoring. Practical tips for marketers and administrators.
A practical guide to configuring DNS for email: MX records, SPF syntax, DKIM key generation, and DMARC policies. Configuration examples for popular providers.
Step-by-step HSTS configuration to enforce HTTPS. max-age, includeSubDomains, preload. Nginx, Apache, Cloudflare. Testing and troubleshooting.
Security rules in .htaccess: blocking bots, preventing hotlinking, restricting access, protecting sensitive files and rate limiting.
HTTP header reference: requests and responses, caching, security, and CORS. Tables, examples, and configuration recommendations.
A comparison of HTTP/2 and HTTP/3: multiplexing, QUIC, and server configuration. A practical guide to speeding up a website with modern protocols.
How IP geolocation works: databases, accuracy, and applications in security, analytics, and personalization. A practical guide.
Step-by-step guide to installing free Let's Encrypt SSL certificates on Apache and Nginx. Certbot, auto-renewal, wildcard certificates. A practical guide for webmasters.
Current account security practices in 2026. Password managers, two-factor authentication, passkeys. Migration and recommendations.
A detailed guide to configuring SPF, DKIM, and DMARC records. Protection against spoofing and improved email deliverability. DNS record examples and step-by-step configuration.
Open a tool for the task described in the article.