DNS Terminologies

• Domain Registrar: Amazon Route 53, GoDaddy, …

• DNS Records: A, AAAA, CNAME, NS, …

• Zone File: contains DNS records

• Name Server: resolves DNS queries (Authoritative or Non-Authoritative)

• Top Level Domain (TLD): .com, .us, .in, .gov, .org, …

• Second Level Domain (SLD): amazon.com, google.com, …

  

Amazon Route 53

• A highly available, scalable, fully managed and Authoritative DNS
  • Authoritative = the customer (you) can update the DNS records
• Route 53 is also a Domain Registrar
• Ability to check the health of your resources
• The only AWS service which provides 100% availability SLA
• Each record contains:
  • Domain/subdomain Name – e.g., example.com
  • Record Type – e.g., A or AAAA
  • Value – e.g., 12.34.56.78
  • Routing Policy – how Route 53 responds to queries
  • TTL – amount of time the record cached at DNS Resolvers

Route 53 – Hosted Zones

• A container for records that define how to route traffic to a domain and its subdomains
• Public Hosted Zones – contains records that specify how to route traffic on the Internet (public domain names)
• Private Hosted Zones – contain records that specify how you route traffic within one or more VPCs (private domain names)
• $0.50 per hosted zone

Route 53 – Records TTL (Time To Live)

• High TTL – e.g., 24 hr
  • Less traffic on Route 53
  • Possibly outdated records