Third‑party DNS on ELB

Third‑Party DNS → ELB

[Your Domain Provider]
        |
        | CNAME record (subdomain only)
        V
my-load-balancer-1234567890.us-east-1.elb.amazonaws.com
        |
        V
[Elastic Load Balancer]

Notes:

• Only subdomains (e.g., www.example.com) can use CNAME.
• Root domains (example.com) cannot use CNAME due to DNS rules unless your DNS provider supports ALIAS/ANAME records.
• If ALIAS is not supported, root domain pointing to ELB requires extra workaround (e.g., HTTP redirect).

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Route 53 → ELB

[Route 53 Hosted Zone]
        |
        | ALIAS record
        V
my-load-balancer-1234567890.us-east-1.elb.amazonaws.com
        |
        V
[Elastic Load Balancer]

Notes:

• Works for both root domains and subdomains.
• No CNAME needed.
• ALIAS is AWS-native, so it’s faster and free (no extra DNS query cost).
• Simple integration — Route 53 auto-updates if ELB DNS changes.

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💡 Summary Table:

Feature	Third‑Party DNS	Route 53
Root domain to ELB	❌ Needs ALIAS/ANAME support	✅ ALIAS works
Subdomain to ELB	✅ via CNAME	✅ via ALIAS or CNAME
Auto ELB DNS updates	❌ Manual update	✅ Automatic
Extra cost for DNS lookups	⚠ Depends on provider	❌ No extra cost