What DNS Does

DNS (Domain Name System) is the phone book of the internet. When you type example.com, DNS translates that to an IP address like 93.184.216.34 so your browser knows which server to connect to.

How a DNS Lookup Works

1. You type example.com in your browser
2. Browser checks its local cache — already know the IP? Skip ahead.
3. Asks your ISP's recursive resolver
4. Resolver asks a root nameserver "who handles .com?"
5. Root says "ask the .com TLD nameserver"
6. TLD nameserver says "example.com uses nameservers ns1.example.com"
7. Resolver asks example.com's nameserver for the IP
8. Gets the answer, caches it, returns to your browser
9. Browser connects to the IP address

This entire process happens in under 100ms.

DNS Record Types

A Record

Maps a domain to an IPv4 address.

example.com → 93.184.216.34

AAAA Record

Maps a domain to an IPv6 address.

example.com → 2606:2800:220:1:248:1893:25c8:1946

CNAME Record

Points a domain to another domain (alias).

www.example.com → example.com
blog.example.com → hosting-provider.com

Note: CNAMEs can't be used on the root domain (example.com) in standard DNS. Cloudflare's "CNAME flattening" works around this.

MX Record

Routes email to mail servers.

example.com → mail.google.com (priority 10)

TXT Record

Stores text data. Used for email authentication (SPF, DKIM, DMARC), domain verification, and more.

NS Record

Declares which nameservers are authoritative for the domain.

DNS Propagation

When you change DNS records, the change doesn't happen instantly. Old records are cached by resolvers worldwide based on the TTL (Time to Live) value.

• Low TTL (300 seconds): Changes propagate in ~5 minutes
• Default TTL (3600 seconds): Changes propagate in ~1 hour
• High TTL (86400 seconds): Changes can take up to 24 hours

Pro tip: Lower your TTL to 300 before making changes, wait for the old TTL to expire, then make your change. It'll propagate much faster.

Troubleshooting DNS

Check current DNS

dig example.com
nslookup example.com

Check propagation worldwide

Use our scanner tool or sites like dnschecker.org to verify DNS has propagated globally.

Common issues

• NXDOMAIN: Domain doesn't exist in DNS (misconfigured nameservers)
• SERVFAIL: Nameserver error (check your DNS provider's status page)
• Slow resolution: TTL too high, or nameservers are geographically distant