DNS Explained: What Every Domain Owner Needs to Know
When you type a domain name into your browser, the browser needs to look up the domain's address. Understanding DNS is especially important when you transfer a domain between registrars. When you type a domain name into your browser, the browser needs to look up the domain's address — the numeric IP addresdomain's address — the numeric IP address of the server where the website is hosted. The Domain Name System, or DNS, is the infrastructure that performs this lookup. Understanding DNS is practically useful for every domain owner because most "website is down" problems are DNS configuration issues.
Key DNS Record Types
A record: Points your domain to an IPv4 IP address. This is what makes a domain resolve to your web server.
AAAA record: Same as A record but for IPv6 addresses.
CNAME record: Points one domain or subdomain to another domain name. Commonly used for www pointing to the root domain, or connecting subdomains to external services.
MX record: Tells email servers where to deliver email for your domain. Without correct MX records, email to your domain cannot be delivered.
TXT record: Contains text information, used for email authentication (SPF, DKIM), domain ownership verification, and connecting third-party services.
NS record: Specifies which DNS servers are authoritative for your domain. Set at your registrar.
How DNS Propagation Works
When you make a DNS change, it does not take effect immediately everywhere. DNS servers cache records for a period specified by the TTL (Time to Live) value. Propagation typically completes within one to three hours for TTL values of 3600 seconds, and up to 48 hours for TTL values of 86400 seconds.
Practical tip: if you are planning a website migration, reduce the TTL to 300 seconds 24 hours before the migration. This minimizes propagation delay when you point the domain to the new server.
Using the DNS Lookup Tool
Domain 360's WHOIS tool at domain360.site/whois includes a DNS Lookup tab showing all DNS records for any domain. Use it to verify DNS changes have propagated, check competitor infrastructure, diagnose email delivery issues by examining MX records, and verify domain ownership through TXT records.
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