OPS535 DNS Review

Name Resolution on Linux systems

• control file: /etc/nsswitch.conf

File Based Name Resolution

Flat file name resolution

• mapping information store in /etc/hosts
• same contents on each system share the same name space

DNS name resolution

• use client-server model

DNS Client (Resolver)

• Configuration file: /etc/resolv.conf - mainly tells the local computer which machines should be used to answer your DNS queries.

DNS Server (BIND)

• Configuration file: /etc/named.conf - server options and which domains are their resposibility
• Zone files: location specified in the /etc/named.conf - contains information of the zone(s)
• Role of server:
  • Cache-only server
  • Primary Server
  • Secondary Server
  • Root name server