in.named, named - Internet domain name server (DNS)
in.named [-d debuglevel] [-p port#] [ [-b | -c]
config_file] [-fqrv] [-u user_name] [-g group_name] [-t
directory] [-w directory] [config_file]
in.named is the Internet domain name server. For more
information on the Internet name-domain system, see RFC
1033, RFC 1034 and RFC 1035.
When run without any arguments, in.named reads the default
configuration file /etc/named.conf, reads any initial data,
and listens for queries. If you give a config_file argument
at the end of the command line, it will override any
config_file that you specified by using the -b or -c
The named.conf(4) configuration file controls some of the
options and behavior for in.named.
in.named supports the following options:
Use an alternative configuration file. The default
value for configfile is /etc/named.conf. The config-
file, if any, specified at the end of the command
line, overrides any value specified by this argument.
Print debugging information. The value of debuglevel
determines the level of messages to print. If nega-
tive, debuglevel is set to 1.
The new debugging framework is considerably more
sophisticated than in previous versions of in.named.
The logging statement in the configuration file allows
for multiple, distinct levels of debugging for each of
a large set of categories of events, for example, for
queries and transfers in and out. See named.conf(4).
-f Run this process in the foreground. The process will
not fork(2). By default, in.named runs as a daemon in
Specify the group the server should run as after it
initializes. The value specified may be either a group
name or a numeric group id.
Use the specified remote port number. in.named will
send queries to this port number. By default, the
value is the standard port number, that is, the port
number returned by getservbyname(3SOCKET) for the ser-
The in.named command previously supported the syntax:
where port# was the first port used when contacting
remote servers and localport# was the service port
bound by the local instance of in.named.
The current usage is equivalent to the old usage
without localport# specified. This functionality can
be specified with the listen-on clause options state-
ment in the configuration file.
-q Trace all incoming queries. This option is deprecated
in favor of the queries logging category of the log-
ging statement in named.conf. See named.conf(4).
-r Turn recursion off in the server. Responses come only
from local (primary or secondary) zones. You can use
this option on root servers. By default, the server
uses recursion. This option is deprecated and is over-
riden by the recursion clause of the options statement
in the configuration file.
Specify the directory that the server is to chroot(2)
into when it finishes processing command line argu-
Specify the user that the server should run as after
it initializes. The value of user_name may be either a
user name or a numeric user id. If the -g option is
not invoked, then the group id will be the primary
group of the user specified. Since initgroups(3C) is
called, all of the user's group will be available to
-v Report the version and exit.
Set the working directory of the server. The direc-
tory clause of the options statement overrides any
value specified on the command line. The default work-
ing directory is the current directory (".").
For compatibility with older implementations any additional
argument will be interpreted as the name of the configura-
tion file. This argument overrides any config_file speci-
fied by means of the -b or -c options. If no further argu-
ment 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 resources for objects in the zone. The file has the fol-
The fields are defined as follows:
The value of domain can be ``.'' 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 not modi-
This field is used to define an origin for the data in
an included file. It is equivalent to placing an $ORI-
GIN 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 An integer number that sets the default time-to-live
for future records that do not have an explicit ttl.
An optional integer number for the time-to-live field.
If not set the ttl is taken from the last $TTL state-
ment. If no $TTL statement has occurred then the SOA
minimum value is used, and a warning is generated.
The object address type. Currently only one type is
supported, IN, for objects connected to the DARPA
type This field contains one of the following tokens. The
data expected in the resource_record_data field is in
A A host address (dotted-quad IP address).
NS An authoritative name server (domain).
MX A mail exchanger (domain), preceded by a prefer-
ence value (0..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 main-
tainer, a serial number and the following param-
eters in seconds: refresh, retry, expire and
minimum ttl). See RFC 883 and RFC 2308.
NULL A NULL resource record (no format or data).
RP A Responsible Person for some domain name
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 semi-
colons and continue to the end of the line.
There are other resource record types not shown here.
Some resource record types may have been standardized
in more recent RFCs, but they have not yet been imple-
mented 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 that 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 by means of concatenation rather than multiplication and
addition. You can spell out the year, month, day of month,
and 0..99 version number and still fit inside the unsigned
32-bit size of this field. (It's true that we will have to
rethink this strategy in the year 4294, but we're not wor-
ried about it.)
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. See RFC 2308.
default name server configuration file.
the process ID.
in.named's current working directory, usually set by
the "directory" options statement in named.conf.
dump of the name server database.
name server statistics data.
See attributes(5) for descriptions of the following attri-
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
| Availability | SUNWinamd |
| Interface Stability | Standard BIND 8.2.4 |
kill(1), named-xfer(1M), chroot(2), fork(2),
getservbyname(3SOCKET), resolver(3RESOLV), signal(3C),
syslog(3C), resolv.conf(4), attributes(5)
Andrews, M. RFC 2308, Negative Caching of DNS Queries (DNS
NCACHE). Network Working Group. March 1998.
Braden, R., editor. RFC 1123, Requirements for Internet
Hosts - Applications and Support . Network Working Group.
Lotter, M. RFC 1033, Domain Administrators Operations Guide.
Network Working Group. November 1987.
Mockapetris, Paul. RFC 882, Domain Names - Concepts and
Facilities. Network Working Group. November 1983.
Mockapetris, Paul. RFC 883, Domain Names - Implementation
and Specification. Network Working Group. November 1983.
Mockapetris, Paul. RFC 973, Domain System Changes and
Observations. Network Working Group. January 1986.
Mockapetris, Paul. RFC 1034, Domain Names - Concepts and
Facilities. Network Working Group. November 1987.
Mockapetris, Paul. RFC 1035, Domain Names - Implementation
and Specification. Network Working Group. November 1987.
Partridge, Craig. RFC 974, Mail Routing and the Domain
System. Network Working Group. January 1986.
Vixie, Paul, Dunlap, Kevin J., Karels, Michael J., Name
Server Operations Guide for BIND Internet Software Consor-
The boot file directives domain and suffixes are now
obsolete. They have been replaced by a resolver-based imple-
mentation of suffixing for partially-qualified domain names.
The earlier mechanisms failed under a number of situations,
for example, when the local name server did not have
The following signals have the specified effect when sent to
the server process using the kill(1) command:
Causes the server to read named.conf and reload the
database. SIGHUP will also cause the server to check
the serial number on all secondary zones.
Dumps the current database and cache to named_dump.db.
Dumps statistics data into named.stats. Statistics
data is appended to the file.
Saves any modified dynamic zones to the file system
and shuts down the server.
Turns on debugging. Each additional SIGUSR1 signal
increments the debug level.
Turns off debugging completely.
Toggles logging of all incoming queries by means of
Man(1) output converted with