Routing & ResolutionRFC 1035

CNAME Record — CNAME Record (Canonical Name / Alias)

Creates an alias pointing one domain or subdomain to another domain name.

RECORD TYPE

CNAME

STANDARD RFC

RFC 1035

DEFAULT TTL

3600 seconds (1 hour)

BIND Zone File Syntax Example

www.example.com. 3600 IN CNAME cname.vercel-dns.com.

How to Query & Check CNAME Records

Linux / Mac (dig)

dig +short CNAME www.example.com

Windows / Generic (nslookup)

nslookup -type=CNAME www.example.com

PowerShell (Resolve-DnsName)

Resolve-DnsName -Name www.example.com -Type CNAME

Recommended Best Practices

According to RFC 1035, you CANNOT place a CNAME record at the zone apex (`example.com`) if MX or NS records exist. Use CNAME Flattening or ALIAS records for root domains.

Primary Use Cases:

•Aliasing `www` to your root domain or edge host (`cname.vercel-dns.com`)
•Configuring custom subdomains for SaaS tools (`status.example.com` -> `statuspage.io`)
•Automated SSL certificate validation (ACM, Let's Encrypt DNS challenges)

Common Configuration Mistake

Attempting to create a CNAME record on the root domain `example.com` on providers that do not support CNAME flattening, breaking email delivery.

Always verify records using authoritative queries (`dig @1.1.1.1 $CNAME example.com`) to bypass local ISP caching when debugging propagation delays.

Frequently Asked Questions

DNS CNAME Record Questions & Answers

Common questions regarding DNS propagation, TTL settings, and zone file syntax.

The CNAME (Canonical Name) record instructs DNS resolvers to restart the query using the target domain name. It is the standard method for mapping subdomains (`www.example.com` or `shop.example.com`) to SaaS providers (Vercel, Shopify, Netlify, GitHub Pages).

Explore Other DNS Record Types

View All DNS Directory

A RecordA Record AAAA RecordAAAA Record ALIAS RecordALIAS / ANAME Record MX RecordMX Record TXT RecordTXT Record SPF RecordSPF Record