• SOA records
  • name of the server that supplied data for the zone
  • zone admin
  • version of data file
  • # of seconds for the TTL file on resource files
• Amazon is a domain register
• ALIAS records
  • map resource record sets to , or buckets
  • difference to CNAME
    • can’t be used for naked domain names (without A-record, also zone as zone apex record)
  • map one DNS name to another DNS name
  • Route53 will automatically change response v4 for alias records
  • requests for CNAME will be charged
    • use ALIAS instead

Routing policies

Simple

• single resource that performs a given function for the domain
• round robbin

Weighted

• example:
  • send 20% of traffic to one region
  • send 80% of traffic to another region
• split traffic based on assigned weights

Latency

• route traffic based on the lowest network latency for the end user
• have to define region

Failover

• when you want to create an active/passive setup

Geolocation

• routing based on the geographic location of the client

Multivalue answer

• route traffic randomly to multiple resources
• example
  • web-servers get DNS responses containing list of available IP addresses for the web servers