The Domain Name System (DNS) is often called the phone book of the internet. It translates human-readable domain names into IP addresses that computers use to communicate.
How DNS Works
When you type a URL into your browser:
- Your browser checks its cache for a recent DNS lookup
- If not found, it queries your operating system's DNS cache
- The request goes to your configured DNS resolver
- The resolver queries root name servers, then TLD servers, then authoritative name servers
- The IP address is returned and cached
Types of DNS Records
A Records
A records map a domain name to an IPv4 address. For example, "example.com" to "93.184.216.34".
MX Records
MX records specify mail servers responsible for receiving email for a domain, with priority values for failover.
TXT Records
TXT records contain text information commonly used for SPF, DKIM, domain verification, and DMARC policies.
CNAME Records
CNAME records create aliases from one domain to another, useful for pointing subdomains to external services.
Common DNS Issues
- DNS Propagation: Changes can take up to 48 hours to propagate globally
- Email Issues: Often caused by incorrect MX or SPF records
- Website Not Loading: May indicate incorrect A record configuration
Best Practices
- Use low TTL values when planning changes
- Have at least two name servers for redundancy
- Implement SPF, DKIM, and DMARC for email security
- Document all DNS records and their purposes
Using Our DNS Lookup Tool
Our free DNS Lookup tool allows you to query any domain and view all its DNS records organized by type. Simply enter a domain name and click Lookup to see A, AAAA, MX, NS, TXT, CNAME, and SOA records.
