Domain Name System
A Domain Name System (DNS) translates a domain name such as www.example.com to an IP address.
DNS is hierarchical, with a few authoritative servers at the top level. Your router or ISP provides information about which DNS server(s) to contact when doing a lookup. Lower level DNS servers cache mappings, which could become stale due to DNS propagation delays. DNS results can also be cached by your browser or OS for a certain period of time, determined by the time to live (TTL).
- NS record (name server) - Specifies the DNS servers for your domain/subdomain.
- MX record (mail exchange) - Specifies the mail servers for accepting messages.
- A record (address) - Points a name to an IP address.
- CNAME (canonical) - Points a name to another name or CNAME (example.com to www.example.com) or to an A record.
Services such as CloudFlare and Route53 provide managed DNS services. Some DNS services can route traffic through various methods:
- Weighted Round Robin
- Prevent traffic from going to servers under maintenance
- Balance between varying cluster sizes
- A/B testing
- Latency Based
- Geolocation Based
To learn more, visit the following links: