name server

An independently managed DNS subtree is called a zone.

A name server is responsible for one or more zones. The administrator of a zone must provide a primary name server and at least one secondary name server for the zone. Primary, secondary names The servers must be independent and redundant so that a failure of a name server does not affect the name service for that zone.

Primary name server: Loads all information for the zone from a disk file.

Secondary name server: Loads all information for the zone from the primary server Importing all information. We will pull in information from the master server called zone transfer.

Once the authority for a zone is delegated, it is responsible for providing multiple name servers to that zone. When a new system is added to a zone, The zone's DNS manager applies for a domain name and an IP address for the new system and adds them to the name server's database. This is where the authority exists.

When a new host joins a zone, The zone manager adds the appropriate information (name and IP address, etc.) to a disk file running on the primary name server, and then tells the primary name server to reload its configuration file. The secondary name server is scheduled (usually 3 hours) Ask the primary name server if there is any new data. If so, get the new data by zone transfer

All primary name servers must know the IP address of the root server. The root server knows the IP of each authoritative name server in all secondary domains address.