What Is DNS?
The Domain Name System (DNS) is the internet's phone book. It translates human-readable domain names like dailyutil.com into machine-readable IP addresses like 104.21.15.72.
Without DNS, you'd need to memorise IP addresses for every website you visit.
How DNS Resolution Works
When you type dailyutil.com in your browser, here's what happens:
- Browser cache - checks if it already knows the IP
- OS cache - checks the operating system's DNS cache
- Recursive resolver - your ISP's DNS server (or 8.8.8.8 / 1.1.1.1)
- Root nameserver - knows where to find
.comservers - TLD nameserver - knows where to find
dailyutil.com's authoritative server - Authoritative nameserver - has the actual DNS records
- Response - IP address flows back through the chain
This entire process typically takes 20-120ms and the result is cached at each level.
DNS Record Types
A Record
Maps a domain to an IPv4 address.
dailyutil.com → 104.21.15.72
AAAA Record
Maps a domain to an IPv6 address.
dailyutil.com → 2606:4700:3030::6815:f48
CNAME Record
Creates an alias - points one domain to another.
www.dailyutil.com → dailyutil.com
MX Record
Specifies the mail server for a domain, with priority.
dailyutil.com → 10 mail.google.com
TXT Record
Stores text data - used for SPF, DKIM, domain verification.
dailyutil.com → "v=spf1 include:_spf.google.com ~all"
NS Record
Specifies the authoritative nameservers for a domain.
dailyutil.com → ns1.cloudflare.com
SOA Record
Start of Authority - contains zone metadata (primary NS, admin email, serial number, TTL values).
PTR Record
Reverse DNS - maps an IP address back to a hostname.
DNS Caching and TTL
Each DNS record has a TTL (Time to Live) - the number of seconds the record can be cached before it must be refreshed.
| TTL | Use Case |
|---|---|
| 300 (5 min) | Dynamic IPs, during migrations |
| 3600 (1 hr) | Standard websites |
| 86400 (24 hr) | Stable, rarely-changed records |
Pro tip: Lower your TTL to 300 seconds before a DNS migration, then raise it back after the change propagates.
Common DNS Issues
- Propagation delays - DNS changes can take up to 48 hours to propagate globally (though usually 1-2 hours)
- Stale cache - flush with
ipconfig /flushdns(Windows) orsudo dscacheutil -flushcache(macOS) - Wrong nameservers - ensure your registrar points to the correct NS records
- Missing SPF/DKIM - emails go to spam without proper TXT records
- CNAME at root - standard DNS doesn't allow CNAME at the zone apex; use ALIAS or ANAME records
Look Up DNS Records
Use our DNS Lookup Tool to query A, AAAA, MX, TXT, NS, CNAME, SOA, and PTR records for any domain - instantly in your browser.