ndc -- name daemon control program


ndc [ -c channel ] [ -l localsock ] [ -p pidfile ] [ -dqst ] [ command [ arg ... ] ]


The ndc command allows a system administrator to control the operation of a name server. If no command is specified, ndc will prompt for commands until it reads EOF.

Also see rndc(1Mtcp), introduced with BIND 9.

ndc understands the following options:

-c channel
Specifies the channel to be used for control. The default channel, /etc/inet/ndc, is a UNIX domain socket which is also the server's default control channel. If the desired control channel is a TCP/IP socket, then the format of the channel argument is ipaddr/port. For example, ``'' specifies TCP port 54 on the local host.

Turns on debugging output.

-l localsock
Binds the client side of the control channel to a specific address. Servers can be configured to reject connections which do not come from specific addresses. The format of the localsock argument is the same as the channel argument to the -c option.

-p pidfile
For backward compatibility with older name servers, ndc can control a name server by sending UNIX signals to a process ID specified in a pidfile. This capability is optional in modern name servers and will disappear altogether at some future time. Note that the signal interface only provides a restricted command set. The default pidfile is /etc/inet/

Suppresses prompts and result text.

Suppresses nonfatal error announcements.

Increments the level of protocol and system tracing.
The following commands are built into ndc:

/debug or /d
Toggle debugging output.

Force named to dump its database and cache to /var/tmp/named_dump.db. (Equivalent to sending SIGINT to the named process.)

/exit or /e
Leave ndc.

List builtin commands.

/help or /h
Provide full information on builtin commands.

Turn off tracing. (Equivalent to sending SIGUSR2 to the named process.)

querylog or qrylog
Cause named to toggle the query logging feature. If query logging is on, this causes a syslog(3G) of each incoming query. Note that query logging consumes a lot of log file space. (Equivalent to sending SIGWINCH to the named process.)

/quiet or /q
Toggle the suppression of prompts and result text.

reload [ zone ... ]
Make named check the serial numbers of all primary and secondary zones, and reload those that have changed. If only certain zones are to be checked for reloading, these can be specified as arguments to reload. (Equivalent to sending SIGHUP to the named process.)

Kill and restart named.

/silent or /s
Toggle reporting of non-fatal errors.

Start named provided that it is not already running. (pidfile mode only)

Force named to dump its statistics to /var/tmp/named.stats. (Equivalent to sending SIGABRT to the named process.)

Stop named provided that it is running.

Increment trace level. (Equivalent to sending SIGUSR1 to the named process.)

/trace or /t
Toggle protocol and system tracing (useful in installation debugging).


named(1Mtcp), rndc(1Mtcp), named.conf(4tcp)


ndc may be used to control the operation of name servers running on remote machines provided that they are running at least version 8.2.1 of BIND and that they have been configured to allow remote control as described in named.conf(4tcp).

If running in pidfile mode, any arguments to the start and restart commands are passed to the new named via its command line. If running in channel mode, there is no start command and the restart command instructs the name server to re-execute itself.


Paul Vixie (Internet Software Consortium).
© 2004 The SCO Group, Inc. All rights reserved.
UnixWare 7 Release 7.1.4 - 25 April 2004