Distributed Name Service (DNS) Management Operations Manual

Working With Different DNS Configurations
Using DNSCOM
6–6 31258 Tandem Computers Incorporated
If neither a system name nor number is passed, DNSCOM attempts to open the
name manager on the system where DNSCOM is running.
When a START DNS command is processed by DNSCOM, DNSCOM attempts to
open the DNS configuration on a system determined as follows:
If the AT \ system parameter is included in the START DNS command,
DNSCOM attempts to open the configuration file on that system.
Otherwise, DNSCOM attempts to open the $SYSTEM.SYSTEM.DNSCONF at the
system specified by the most recent CMDSYS command. If no CMDSYS
command has been entered, the system passed in the STARTUP.DEFAULTS is
used. If no system was passed in the STARTUP.DEFAULTS, the system where
DNSCOM is running is assumed.
DNSCOM Determines Its
Default Configuration File
The default configuration file used by DNSCOM is determined as follows:
If the DEFINE =_DNS_CONFIG is present, verification checks are performed on
the associated file (the specified configuration file); these checks are described in
Appendix A. If the file is a valid DNS configuration file, it becomes the current
configuration file. If the file is invalid, the following error message is generated
and $SYSTEM.SYSTEM.DNSCONF becomes the current configuration file.
ERROR 71 - Illegal Configuration File - file name
If =_DNS_CONFIG is not present, $SYSTEM.SYSTEM.DNSCONF becomes the
current configuration file.
Changing the Default
Configuration File
While DNS provides a default configuration file ($SYSTEM.SYSTEM.DNSCONF), you
can change this default.
The default DNS configuration file used by DNSCOM is determined by the map
DEFINE =_DNS_CONFIG. If this DEFINE is missing, DNSCOM defaults to
$SYSTEM.SYSTEM.DNSCONF for its default configuration file.
By defining =_DNS_CONFIG in different places, you can change its scope.
For a single TACL session, you can add =_DNS_CONFIG with the following
command from your TACL prompt:
ADD DEFINE =_DNS_CONFIG, FILE file name
The default for a particular user can be changed by placing this command in the user’s
TACLCSTM file.
To change the default for an entire system, the above command can be placed in the
TACLLOCL file. When this is done, a different default can be assigned for a particular
user by placing the following command in the user’s TACLCSTM file:
ALTER DEFINE =_DNS_CONFIG, FILE file name
For more information on TACL files, refer to the Guardian 90 Operating System User’s
Guide and the Tandem Advanced Command Language (TACL) Reference Manual, Volumes
1 and 2.