DNS 101

  • SOA Start of Authority
  • NS Name Server
  • Top level domain server contains only NS records
  • A record Address record translate name to ip address
  • TTL Time to Live caching of Resolving server
  • CName Canonical Name resolve one domain name to another
  • Alias Same as CNAME → cannot be used for naked domain names
  • ELB don’t have pre-defined IPV4 Addresses
  • Domain name can be bought directly from Amazon
  • It could take 3 days to register a domain name.

Route53 Routing Policies

Simple Routing

  • Randomly select one ip from multiple ip address from One record

Weighted Routing

  • 80%/20% traffic to different IP Address

Latency-based Routing

  • Route traffic based on lowest network latency

Failover Routing

  • Active/Passive Set up.

Geolocation Routing

  • Based on Geo Location of the user

Geoproximity Routing(Traffic Flow only)

  • Based on both Geographic location of users and resources

Multivalue Answer Routing

  • Return multiple ip address
  • Make sure it pass health check before returning