Named
is the Internet domain name server.
See RFC's 1033, 1034, and 1035 for more information on the Internet
name-domain system. 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 by using the
Fl b
or
Fl c
flags.
NOTE:
Several of
named Ns 's
options, and much more of its behaviour, can be controlled in the configuration
file. Please refer to the configuration file guide included with this
BIND
distribution for further information.
Options are:
-tag -width Fl
Fl d Ar debuglevel
Print debugging information.
The
debuglevel
is a number 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
Li 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,
etc.). Please refer to the configuration file guide included with this
BIND
distribution for further information about these extensive new capabilities.
Fl p Ar 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, i.e.,
the port number returned by
getservbyname 3
for service
Li domain .
NOTE:
Previously, the syntax
Fl p Ar port# Ns Op Ar /localport#
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
localport#
specified; this functionality can be specified with the
Li listen-on
clause of the configuration file's
Li options
statement.
Xo Fl Po
b Ns | Ns Cm c
Ar config_file
Use an alternate
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 .
Fl f
Run this process in the foreground; don't
fork 2
and daemonize. (The default is to daemonize.)
Fl q
Trace all incoming queries if
NAMED
has been compiled with
QRYLOG
defined.
NOTE:
This option is deprecated in favor of the
Li queries
logging category
of the configuration file's
Li logging
statement; for more information, please refer to the configuration file guide
included with this distribution of
BIND .
Fl 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
Li recursion
clause of the configuration file's
Li options
statement.
Fl v
Report the version and exit.
Fl u Ar 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
Fl 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).
Fl g Ar 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.
Fl t Ar directory
Specifies the directory the server should chroot() into as soon as it is
finshed processing command line arguments.
Fl w Ar directory
Sets the working directory of the server. The
Li directory
clause of the configuration file's
Li options
statement overrides any value specified on the command line.
The default working directory is the current directory
Dq . .
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 by the use of the
Fl b
or
Fl c
flags. If no further argument is given, then the default configuration file
is used
Pa /etc/named.conf .
The master file consists of control information and a list of resource
records for objects in the zone of the forms:
-literal -offset indent
$INCLUDE <filename> <opt_domain>
$ORIGIN <domain>
$TTL <ttl>
<domain> <opt_ttl> <opt_class> <type> <resource_record_data>
where:
-tag -width "opt_domain "
Ar domain
is
Li .
for root,
Li @
for the current origin, or a standard domain name. If
domain
is a standard domain name that does
not
end with
Li . ,
the current origin is appended to the domain. Domain names ending with
Li .
are unmodified.
Ar 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. The field is optional.
Neither the
opt_domain
field nor
$ORIGIN
statements in the included file modify the current origin for this file.
Ar ttl
A integer number that sets the default time-to-live for future records without
an explicit ttl.
Ar opt_ttl
An optional integer number for the time-to-live field.
If not set the ttl is taken from the last $TTL statement.
If no $TTL statement has occured then the SOA minimum value is used and a
warning is generated.
Ar opt_class
The object address type; currently only one type is supported,
IN ,
for objects connected to the DARPA Internet.
Ar type
This field contains one of the following tokens; the data expected in the
resource_record_data
field is in parentheses:
-tag -width "HINFO " -offset indent
Dv A
a host address (dotted-quad IP address)
Dv NS
an authoritative name server (domain)
Dv MX
a mail exchanger (domain), preceded by a preference value (0..32767),
with lower numeric values representing higher logical preferences.
Dv CNAME
the canonical name for an alias (domain)
Dv 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
and RFC 2308)).
Dv NULL
a null resource record (no format or data)
Dv RP
a Responsible Person for some domain name (mailbox, TXT-referral)
Dv PTR
a domain name pointer (domain)
Dv 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. You should
consult the
BIND
Operations Guide
Dq BOG
for the complete
list. Some resource record types may have been standardized in newer RFC's
but not yet implemented in this version of
BIND .
Each master zone file should begin with an SOA record for the zone.
An example SOA record is as follows:
-literal
@ 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 changed 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 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 worried 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 (RFC 2308).
