is a Domain Name System (DNS) server, part of the BIND 9 distribution from ISC. For more information on the DNS, see RFCs 1033, 1034, and 1035.
When invoked without arguments,
named
will read the default configuration file
/etc/namedb/named.conf, read any initial data, and listen for queries.
OPTIONS
-4
Use IPv4 only even if the host machine is capable of IPv6.
-4
and
-6
are mutually exclusive.
-6
Use IPv6 only even if the host machine is capable of IPv4.
-4
and
-6
are mutually exclusive.
-c config-file
Use
config-file
as the configuration file instead of the default,
/etc/namedb/named.conf. To ensure that reloading the configuration file continues to work after the server has changed its working directory due to to a possible
directory
option in the configuration file,
config-file
should be an absolute pathname.
-d debug-level
Set the daemon's debug level to
debug-level. Debugging traces from
named
become more verbose as the debug level increases.
-f
Run the server in the foreground (i.e. do not daemonize).
-g
Run the server in the foreground and force all logging to
stderr.
-m flag
Turn on memory usage debugging flags. Possible flags are
usage,
trace,
record,
size, and
mctx. These correspond to the ISC_MEM_DEBUGXXXX flags described in
<isc/mem.h>.
-n #cpus
Create
#cpus
worker threads to take advantage of multiple CPUs. If not specified,
named
will try to determine the number of CPUs present and create one thread per CPU. If it is unable to determine the number of CPUs, a single worker thread will be created.
-p port
Listen for queries on port
port. If not specified, the default is port 53.
-s
Write memory usage statistics to
stdout
on exit.
Note:
This option is mainly of interest to BIND 9 developers and may be removed or changed in a future release.
-t directory
Chroot to
directory
after processing the command line arguments, but before reading the configuration file.
Warning:
This option should be used in conjunction with the
-u
option, as chrooting a process running as root doesn't enhance security on most systems; the way
chroot(2)
is defined allows a process with root privileges to escape a chroot jail.
-u user
Setuid to
user
after completing privileged operations, such as creating sockets that listen on privileged ports.
Note:
On Linux,
named
uses the kernel's capability mechanism to drop all root privileges except the ability to
bind(2)
to a privileged port and set process resource limits. Unfortunately, this means that the
-u
option only works when
named
is run on kernel 2.2.18 or later, or kernel 2.3.99-pre3 or later, since previous kernels did not allow privileges to be retained after
setuid(2).
-v
Report the version number and exit.
-x cache-file
Load data from
cache-file
into the cache of the default view.
Warning:
This option must not be used. It is only of interest to BIND 9 developers and may be removed or changed in a future release.
SIGNALS
In routine operation, signals should not be used to control the nameserver;
rndc
should be used instead.
SIGHUP
Force a reload of the server.
SIGINT, SIGTERM
Shut down the server.
The result of sending any other signals to the server is undefined.
CONFIGURATION
The
named
configuration file is too complex to describe in detail here. A complete description is provided in the
BIND 9 Administrator Reference Manual.