CNAME Flattening is Not a Crime

    Break the rules. Bend reality. Learn why root-level CNAMEs are "forbidden" and how modern CDNs make the impossible possible.

    A Records vs CNAMEs: The Eternal Battle

    A Records: The Truthtellers

    Direct, honest, and boring. They point straight to an IP address with no tricks.

    A Record Lookup
    dig example.com A +short
# Output: 93.184.216.34

    CNAMEs: The Shape-shifters

    Magical aliases that redirect you to another domain. Pure misdirection.

    CNAME Lookup
    dig www.github.com CNAME +short
# Output: github.com.

    The Root Domain Prohibition

    According to RFC 1034, you cannot have a CNAME record at the root domain (like example.com) because it would conflict with mandatory records like SOA and NS.

    ❌ This Should Fail:

    example.com. IN CNAME target.example.com.

    But what if we told you... the rules are more like guidelines? 🏴‍☠️

    The Reality-Bending Machine

    ⚡🔧⚡

    CNAME FLATTENING ENGINE

    CDNs like Cloudflare intercept DNS queries and perform real-time lookups. When you query a root domain with a "flattened CNAME", they resolve the target and return an A record instead.

    1. Configure
    example.com CNAME target.com
    2. Flatten
    DNS query intercepted & resolved
    3. Respond
    Returns A record: 1.2.3.4

    Real-World Sorcery

    Test CNAME Flattening

    Check cnameflatten.com
    dig cnameflatten.com +short
# Should return an IP, not a CNAME!

curl -I cnameflatten.com
# Watch the magic happen

    The Secret Dashboard

    In your CDN control panel, you'll see something like this:

    📊 DNS Records
    @ CNAME target.datajelly.com ⚡ FLATTENED
    www CNAME cnameflatten.com

    🧠 Hacker Notes

    ✅ Why It Works

    • • CDNs control the authoritative DNS servers
    • • They resolve CNAMEs server-side before responding
    • • Clients only see the final A record
    • • No RFC violations from the client's perspective

    ⚠️ Gotchas

    • • TTL management becomes complex
    • • Some DNS propagation delays
    • • Dependent on CDN infrastructure
    • • Not all DNS providers support this