named.soa(4tcp)
named.soa --
file containing SOA and NS records for a zone
Synopsis
name [ttl] class SOA origin person_in_charge (
serial_number
refresh_time
retry_time
expiry_time
time_to_live )
[ttl] class NS nameserver
Description
A named.soa file is a convenient way of
storing the start of authority (SOA)
and name server (NS) records for
a single zone on a primary server.
The SOA record designates the start of a zone.
The zone ends at the next SOA record.
The information in named.soa is included in
the
named.hosts(4tcp),
named.local(4tcp),
and
named.rev(4tcp)
zone files using the $INCLUDE directive
at the start of the file.
The filename is arbitrary.
For more information on the fields of SOA and NS
records, see
named.hosts(4tcp).
The SOA lists a serial number, which should be
changed each time the master file is changed.
Note that the serial number can be given as a
dotted number, but this is unwise since the
translation to normal integers uses concatenation rather than
multiplication and addition.
You can catenate the year, month, day of
month, and a version number in the range 0-99
and still fit inside the unsigned 32-bit
size of this field.
Secondary
servers check the serial number at intervals specified by
the refresh time in seconds; if the serial number changes,
a zone transfer will be done to load the new data.
If a master server cannot be contacted when a refresh is due,
the retry time specifies the interval at which refreshes
should be attempted.
If a master server
cannot be contacted within the interval given by the expire
time, all data from the zone is discarded by secondary
servers.
NOTE:
From BIND 8.2.1,
the minimum time-to-live value is applied to negative responses.
It is no longer the default minimum
time-to-live value for resource records that do not
specify a ttl value, unless there is no preceding
$TTL in Administering TCP/IP and Internet services
statement. In this case, a warning is generated.
Files
/etc/inet/named.d/named.soa
References
named(1Mtcp),
named.boot(4tcp),
named.hosts(4tcp),
named.local(4tcp),
named.rev(4tcp),
root.cache(4tcp)
RFC 1035,
RFC 2308
Examples
The following example named.soa entries show
a zone with primary name server volga and
secondary name server istanbul,
and which is administered by dave@mynet.com.
@ IN SOA volga.mynet.COM. dave.mynet.COM (
1993091901 ; Serial number
10880 ; Refresh time
1800 ; Retry time
3600000 ; Expiry time
259200 ) ; Minimum time-to-live
IN NS volga.mynet.COM
IN NS istanbul.mynet.COM
© 2004 The SCO Group, Inc. All rights reserved.
UnixWare 7 Release 7.1.4 - 25 April 2004