Domain naming service

Description:

• Translate internet hostnames to IP addresses
• Computer reads domain from right to left, \www.sub.example.com.
  • www. is subdomain
  • example is 2nd level domain
  • .com is top level domain
  • . is root domain
• A record is a mapping between a DNS resource and a domain name.
  • Each individual DNS record has a type (name and number), an expiration time (time to live), and type-specific data.
• There are levels: root server, domain server, name server
• https://cloud.google.com/dns/docs/records-overview

DNS zone:

• A section of a domain name space that a certain administrator has been delegated control over.
  • sub1.example.com
• Public vs private zone:
  • public is resolved on the .com/.net server
  • private zone is resolved at internal dns server
• Split-horizon zone:
  • Can have public and private zone of the same name

Resource record:

• A
  • Address record to resolve domain name to IPv4 address
• AAAA
  • Address record to resolve domain name to IPv6 address
• CNAME
  • Canonical name
  • Resolve a domain or subdomain to another domain name
    • Alias of one name to another
    • the DNS lookup will continue by retrying the lookup with the new name.
    • Point subdomain to domain, fpt.example.com to example.com
• MX
  • Mail exchanger
• SOA
  • Start of authority
  • Stores administrative information about a DNS zone
  • MNAME: primary name server
  • Name: email address of the administrator for the zone where second dot is @
  • Serial: represents a version in a zone
• NS:
  • Name server
• SRV
  • Service record