Resource Records - Novell NETWARE 6-DOCUMENTATION Manual

Primary Name Servers
Secondary Name Servers

Resource Records

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Novell DNS/DHCP Management Utility Administration Guide
One DNS name server in each administrative zone maintains an authoritative
database of hostname and address information for an entire domain. This
name server is the primary name server, and the domain administrator updates
it with hostnames and addresses as changes occur.
All name servers maintain information about how to contact name servers that
are at higher or lower levels within the DNS hierarchy. The process of
maintaining information about name servers in higher-level domains is called
linking to the existing DNS hierarchy. The administrator also enters
information into the database about name servers in lower-level domains
when creating a subdomain.
Secondary name servers have read-only copies of the primary name server's
DNS database. Secondary name servers provide redundancy and load
balancing for a domain.
Periodically, and when a secondary name server starts up, the secondary name
server contacts the primary name server and requests a complete copy of the
primary name server's DNS database. This process is called a zone transfer.
If necessary, a primary name server can also function as a secondary name
server for another zone.
Resource records (RRs) contain the host information maintained by the name
servers and make up the DNS database. Different types of records contain
different types of host information. For example, an Address record provides
the name-to-address mapping for a given host, while a Start of Authority
(SOA) record specifies the start of authority for a given zone.
A DNS zone must contain several types of resource records for DNS to
function properly. Other RRs can be present, but the following records are
required for standard DNS:
Name server (NS)—Binds a domain name with a hostname for a specific
name server
The DNS zone must contain NS records for each primary and secondary
name server in the zone. The DNS zone must contain NS records to link
the zone to higher- and lower-level zones within the DNS hierarchy.