DNS Resource Records

DNS server IP addresses configured on a client machine are used to resolve the client’s queries for hosts and domains across the Internet.

At least one DNS server also needs to be configured to act as an authoritative store of information about each domain
- these name servers are normally installed separately from the ones used as client resolvers
DNS name servers maintain the DNS namespace in zones
- single zone namespace might host records for multiple domains
- subdomains within a domain might be managed as multiple zones on multiple servers
DNS zone contains numerous resource records
- allow a DNS name server to resolve queries for names and services hosted in the domain into IP addresses
- can be created and updated statically or generated dynamically from information received from client and server computers on the network
a Start of Authority (SOA) record identifies the primary authoritative name server that maintains complete resource records for the zone
- primary name server can be used to modify resource records
- SOA includes contact information for the zone and a serial number for version control
Name server (NS) records identify authoritative DNS name servers for the zone
the primary name server and most zones are configured with secondary name servers for redundancy and load balancing
- secondary name servers hold read-only copies of resource records
  - can still be authoritative for the zone

adam's notes