named(ADMN)
named --
Internet domain name server
Syntax
named
[-d debuglevel]
[-p port]
[-(b|c) config_file]
[-f -q -r v]
[-u user_name]
[-g group_name]
[-t directory]
[-w directory]
[config_file]
Description
named
is the Internet domain name server.
See RFCs 1033, 1034, and 1035 for more information on the Internet
Domain Name System (DNS). Without any arguments,
named
will read the default configuration file
/etc/named.conf,
read any initial data, and listen for queries. A
config_file
argument given at the end of the command line will override any
config_file
specified with the
-b
or
-c
flags.
NOTE:
Several of
named's
options, and much more of its behavior, can be controlled in the configuration
file. Please refer to the
named.conf(SFF)
manual page
for further information.
Options
named takes the following options:
-d debuglevel-
Print debugging information.
The
debuglevel
is a number that determines the level of messages printed. If negative,
debuglevel
is set to 1.
NOTE:
The new debugging framework is considerably more sophisticated than it
was in older versions of
named.
The configuration file's
logging
statement allows for multiple, distinct levels of debugging for each of
a large set of categories of events (such as queries, transfers in or out,
and so on).
Please refer to the
named.conf(SFF)
manual page
for further information.
-p port-
Use the specified remote port number. This is the port number to which
named
will send queries. The default value is the standard port number: that is,
the port number returned by
getservbyname(SLIB)
for service
domain.
NOTE:
Previously, the
-p port[/localport] syntax
was supported; the first port was that used when contacting
remote
servers, and the second one was the service port bound by the
local
instance of
named.
The current usage is equivalent to the old usage without the
local port
specified; this functionality can be specified with the
listen-on
clause of the configuration file's
options
statement.
-b|-c config_file-
Use an alternative
config_file;
this argument is overridden by any
config_file
which is specified at the end of the command line.
The default value is
/etc/named.conf.
-f-
Run this process in the foreground; don't
fork(S)
and daemonize. The default is to daemonize.
-q-
Trace all incoming queries if
named
has been compiled with
QRYLOG
defined.
NOTE:
This option is deprecated in favor of the
queries
logging category
of the configuration file's
logging
statement.
Please refer to the
named.conf(SFF)
manual page
for further information.
-r-
Turns recursion off in the server. Answers can come only from local
(primary or secondary) zones. This can be used on root servers.
The default is to use recursion.
NOTE:
This option can be overridden by, and is deprecated in favor of, the
recursion
clause of the configuration file's
options
statement.
-v-
Report the version and exit.
-u user_name-
Specifies the user the server should run as after it
initializes. The value
specified may be either a username or a numeric user id. If the
-g
flag is not specified, then the group id used will be the
primary group of
the user specified (initgroups() is called, so all
of the user's groups will be available to the server).
-g group_name-
Specifies the group the server should run as after it
initializes. The value
specified may be either a groupname or a numeric group id.
-t directory-
Specifies the directory the server should chroot() into
as soon as it is finshed processing command line arguments.
-w directory-
Sets the working directory of the server. The
directory
clause of the configuration file's
options
statement overrides any value specified on the command line.
The default working directory is the current directory
Any additional argument is taken as the name of the configuration file, for
compatibility with older implementations. As noted above, this argument
overrides any
config_file
specified with
-b
or
-c.
If no further argument is given, then the default configuration file,
/etc/named.conf,
is used.
Master file format
The master file consists of control information and a list of resource
records for objects in the zone of the form:
$INCLUDE filename opt_domain
$ORIGIN domain
$TTL ttl
domain opt_ttl opt_class type resource_record_data
where:
domain-
This is ``.''
for root,
``@''
for the current origin, or a standard domain name. If
domain
is a standard domain name that does
not
end with
``.'',
the current origin is appended to the domain. Domain names ending with
``.''
are unmodified.
opt_domain-
This field is used to define an origin for the data in an included file.
It is equivalent to placing an
$ORIGIN
statement before the first line of the included file. This field is optional.
Neither the
opt_domain
field nor
$ORIGIN
statements in the included file modify the current origin for this file.
ttl-
A integer number that sets the default time-to-live for future
records without an explicit ttl.
opt_ttl-
An optional integer for the time-to-live field.
It defaults to zero, meaning the minimum value specified in the SOA
record for the zone.
opt_class-
The object address type. Currently only one type is supported,
IN,
for objects connected to the DARPA Internet.
type-
This field contains one of the following tokens. The data expected in the
resource_record_data
field is in parentheses.
A-
a host address (dotted-quad IP address)
NS-
an authoritative name server (domain)
MX-
a mail exchanger (domain), preceded by a preference value (0 to 32767),
with lower numeric values representing higher logical preferences
CNAME-
the canonical name for an alias (domain)
SOA-
marks the start of a zone of authority (domain of originating host,
domain address of maintainer, a serial number and the following
parameters in seconds: refresh, retry, expire and minimum TTL
(see RFC 883))
NULL-
a null resource record (no format or data)
RP-
a Responsible Person for some domain name (mailbox, TXT-referral)
PTR-
a domain name pointer (domain)
HINFO-
host information (cpu_type, OS_type)
Resource records normally end at the end of a line,
but may be continued across lines between opening and closing parentheses.
Comments are introduced by semicolons and continue to the end of the line.
NOTE:
There are other resource record types not shown here.
Refer to
``Configuring the Domain Name Service'' in the Networking Guide
for a list of types.
Some resource record types may have been standardized in newer
RFCs
but not yet implemented in this version of
BIND.
SOA record format
Each master zone file should begin with an SOA record for the zone.
An example SOA record is as follows:
@ IN SOA ucbvax.Berkeley.EDU. rwh.ucbvax.Berkeley.EDU. (
1989020501 ; serial
10800 ; refresh
3600 ; retry
3600000 ; expire
86400 ) ; minimum
The SOA specifies a serial number, which should be
incremented each time the
master file is changed. Note that the serial number can be given as a
dotted number, but this is a
very
unwise thing to do since the
translation to normal integers is via concatenation rather than
multiplication and addition. You can spell out the year, month, day of
month, and the version number (0 to 99) with 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.
The minimum value is the cache time-to-live for negative answers
(RFC 2308).
Notes
The boot file directives,
domain
and
suffixes,
have been
obsoleted by a more useful, resolver-based implementation of
suffixing for partially-qualified domain names. The prior mechanisms
could fail under a number of situations, especially when the local
name server did not have complete information.
The following signals have the specified effect when sent to the
server process using the
kill(C)
command:
SIGHUP-
Causes server to read
named.conf
and reload the database. If the server
is built with the
FORCED_RELOAD
compile-time option, then
SIGHUP
will
also cause the server to check the serial number on all secondary zones.
Normally, the serial numbers are only checked at the SOA-specified intervals.
SIGINT-
Dumps the current data base and cache to
/var/tmp/named_dump.db
or to the value of
_PATH_DUMPFILE.
SIGILL-
Dumps statistics data into
named.stats
if the server is compiled with
-DSTATS.
Statistics data is appended to the file.
SIGSYS-
Dumps the profiling data in
/var/tmp
if the server is compiled with profiling (server forks, chdirs and exits).
SIGTERM-
Dumps the primary and secondary database files.
Used to save modified data on shutdown if the
server is compiled with dynamic updating enabled.
SIGUSR1-
Turns on debugging. Each
SIGUSR1
increments the debug level.
SIGUSR2-
Turns off debugging completely.
SIGWINCH-
Toggles logging of all incoming queries via
syslog(SLIB).
Files
/etc/named.conf-
default name server configuration file
/etc/named.pid-
_PATH_PIDFILE
the process ID
/var/tmp/named_dump.db-
_PATH_DUMPFILE,
dump of the name server database
/var/tmp/named.run-
_PATH_DEBUG,
debug output
/var/tmp/named.stats-
_PATH_STATS,
name server statistics data
See also
gethostbyname(SLIB),
hostname(ADMN),
kill(C),
resolver(SFF),
resolver(SLIB),
signal(S)
``Configuring the Domain Name Service'' in the Networking Guide
RFC 882, RFC 883,
RFC 973, RFC 974, RFC 1033,
RFC 1034, RFC 1035, RFC 1123,
RFC 2308
© 2003 Caldera International, Inc. All rights reserved.
SCO OpenServer Release 5.0.7 -- 11 February 2003