Domain Name System (DNS)
Domain Name System
The system that translates human-readable domain names (like example.com.au) into IP addresses that computers use to identify and communicate with each other on the internet.
In-Depth Explanation
The Domain Name System (DNS) is the internet's directory service, translating domain names that humans can read (like cleverops.com.au) into numerical IP addresses (like 13.55.123.45) that computers use to locate each other. DNS is essential to virtually everything on the internet.
How DNS works:
- User types a domain name in their browser
- Browser checks local DNS cache
- If not cached, query goes to a DNS resolver (usually ISP's)
- Resolver queries root DNS servers, then TLD servers, then authoritative nameservers
- Authoritative nameserver returns the IP address
- Browser connects to the IP address and loads the website
- Result is cached for future lookups
DNS record types:
- A record: Maps domain to IPv4 address
- AAAA record: Maps domain to IPv6 address
- CNAME: Alias pointing one domain to another
- MX record: Mail server routing
- TXT record: Verification and configuration (SPF, DKIM, DMARC)
- NS record: Authoritative nameservers for the domain
- SOA record: Start of Authority with administrative information
DNS providers:
- Cloudflare DNS: Fast, free, with DDoS protection
- AWS Route 53: Integrated with AWS, highly available
- Google Cloud DNS: Global network, low latency
- Azure DNS: Integrated with Azure services
- Domain registrar DNS: GoDaddy, Namecheap, VentraIP (Australia)
DNS security:
- DNSSEC: Validates DNS responses to prevent spoofing
- DNS over HTTPS (DoH): Encrypts DNS queries
- DNS over TLS (DoT): Alternative encryption for DNS
- DDoS protection: Defending DNS infrastructure from attacks
DNS best practices:
- Use a reliable DNS provider with global infrastructure
- Implement low TTLs during migrations for quick changes
- Set up proper MX records for email delivery
- Configure SPF, DKIM, and DMARC TXT records for email security
- Monitor DNS for unauthorised changes
Business Context
DNS outages make websites completely inaccessible regardless of server health. Using a reliable DNS provider with global infrastructure is a low-cost, high-impact way to improve website availability and performance.
How Clever Ops Uses This
Clever Ops manages DNS configuration for Australian businesses, ensuring fast resolution, high availability, and proper security. We configure DNS records for websites, email, and cloud services, implement DNSSEC for security, and optimise DNS for performance using providers like Cloudflare and AWS Route 53.
Example Use Case
"An Australian business migrates DNS from their domain registrar to Cloudflare, gaining 30% faster DNS resolution for Australian users, built-in DDoS protection, and easy management of records for their website, email, and subdomains."