Installing and Administering Internet Services

80 Chapter 3
Configuring and Administering the BIND Name Service
Configuring a Primary Master Name Server
SOA Start of Address record. The SOA record designates the
start of a domain, and indicates that this server is
authoritative for the data in the domain.
In data files, @ represents the current origin. The
current origin is the domain configured in this file,
according to the boot file. The boot file says that the
div.inc.com domain is configured in the db.div file.
Therefore, every instance of @ in the db.div file
represents div.inc.com.
The SOA record indicates the name of the host this data
file was created on, the mailing address of the person
responsible for the name server, and the following
values:
Serial The version number of this file,
incremented whenever the data is
changed.
Refresh Indicates (in seconds) how often a
secondary name server should try to
update its data from a master server.
Retry Indicates (in seconds) how often a
secondary server should retry after
an attempted refresh fails.
Expire Indicates (in seconds) how long the
secondary name server can use the
data before it expires for lack of a
refresh.
Minimum ttl The minimum number of seconds for
the time to live field on other resource
records for this domain.
NS Name Server records. The NS records give the names of
the name servers and the domains for which they have
authority. The domain for the name servers in the
example is the current origin (div.inc.com), because
@ was the last domain specified.
A Address records. The A records give the internet
addresses for all the hosts in the domain.