DOMAIN NAME SYSTEM (DNS) RECORD SYNTAX & DEPLOYMENT ARCHITECTURE
Technical specifications for BIND 9 zone master files, Cloudflare DNS imports, mail authentication standards, and airgap zero-log privacy.
1. Standard Resource Record Format (RFC 1035)
DNS zone records follow the canonical format: <name> <ttl> IN <type> <rdata>.
- A / AAAA Records: Map hostnames directly to 32-bit IPv4 addresses or 128-bit IPv6 addresses.
- CNAME (Canonical Name): Aliases one domain name to another canonical name. CNAME records cannot coexist with other records at the apex (
@) under RFC 1912. - MX (Mail Exchange): Routes incoming SMTP traffic with an explicit numerical preference weight (lower integer = higher delivery priority).
- TXT Records: Carries machine-readable arbitrary text, critically employed by Sender Policy Framework (
SPF), DomainKeys Identified Mail (DKIM), and Domain-based Message Authentication (DMARC). - CAA (Certificate Authority Authorization): Specifies which Certificate Authorities (e.g. Let's Encrypt, DigiCert) are cryptographically authorized to issue SSL/TLS certificates for the domain (RFC 6844).
2. BIND vs Cloudflare Import Formatting
BIND zone files require absolute domain names to terminate with a trailing dot (.); otherwise, the zone origin is automatically appended. Cloudflare DNS accepts standard BIND zone files via its web UI and API, automatically interpreting apex @ notations, TTL values, and multi-string SPF/DMARC quotation delimiters.