named 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
chroot() to /var/lib/bind,
read the default configuration file
/var/lib/bind/etc/named.conf, read any initial
data, and listen for queries.
Use config-file as the
configuration file instead of the default,
ensure that reloading the configuration file continues
to work after the server has changed its working
directory due to a possible
directory option in the configuration
file, config-file should be
an absolute pathname.
Set the daemon's debug level to debug-level.
Debugging traces from named become
more verbose as the debug level increases.
Run the server in the foreground (i.e. do not daemonize).
Run the server in the foreground and force all logging
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.
Listen for queries on port port. If not
specified, the default is port 53.
Write memory usage statistics to stdout on exit.
This option is mainly of interest to BIND 9 developers
and may be removed or changed in a future release.
chroot() to directory after
processing the command line arguments, but before
reading the configuration file.
By default, namedchroot()'s to /var/lib/bind.
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() is
defined allows a process with root privileges to
escape a chroot jail.
setuid() to user after completing
privileged operations, such as creating sockets that
listen on privileged ports.
By default, named will run as user named.
On Linux, named uses the kernel's
capability mechanism to drop all root privileges
except the ability to bind() 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().
Report the version number and exit.
Load data from cache-file into the
cache of the default view.
This option must not be used. It is only of interest
to BIND 9 developers and may be removed or changed in a
In routine operation, signals should not be used to control
the nameserver; rndc should be used
Force a reload of the server.
Shut down the server.
The result of sending any other signals to the server is undefined.
The named configuration file is too complex
to describe in detail here. A complete description is
provided in the BIND 9 Administrator Reference
By default, named is configured to run in readonly chroot jail
/var/lib/bind with no extra privileges.
To configure named as master or caching-only DNS, you don't need
to create files and/or directories writable by named.
To configure named as slave DNS in chroot jail, additional package
bind-slave have to be installed.
To debug named with rndc, additional package
bind-debug have to be installed.