System administrators use the ndc utility to control the operation of a name server. If the system administrator fails to list a command, ndc will prompt for one until it reads EOF.

The ndc command supports the following options:

-c channel

Specify the rendezvous point for the control channel. The default value for channel is /var/run/ndc, a UNIX domain socket that is also the server's default control channel. If the desired control channel is a TCP/IP socket, then the format for the channel argument is ipaddr/port. For example, a value of 127.0.0.1/54 would be TCP port 54 on the local host.

-d

Turn on debugging mode. This option is mainly of interest to developers.

-l localsock

Bind the client side of the control channel to a specific address. Servers can be configured to reject connections that do not come from specific addresses. If the desired control channel is a TCP/IP socket, then the format for the localsock argument is ipaddr/port.

-p pidfile

Use for backwards compatibility with older name servers. It enables ndc to use UNIX signals for control communications. Optional with modern name servers, this capability may not be supported in future releases.The command set that is available is narrower when the signal interface is used. A likely value for the pidfile argument is /var/run/named.pid.

-q

Suppress prompt and result text.

-s

Suppress non-fatal error announcements.

-t

Turn on protocol and system tracing. Use this option in installation debugging.

The following commands are built into the ndc utility. The full set of commands that the name server supports is dynamic. Use the help command for information on the available commands .

/help

Show help information for built in commands.

/exit

Exit from ndc command interpreter.

/trace

Toggle protocol and system tracing on and off. See -t.

/debug

Toggle debugging mode on and off. See -d.

/quiet

Toggle prompt and result information on and off. See -q.

/silent

Toggle announcement of non-fatal errors on and off. See -s.

See attributes(5) for descriptions of the following attributes:

in.named(1M), execvp(2), attributes(5)

When the ndc utility is running in pidfile mode, pass any arguments to start and restart commands to the new name server on the command line. If the ndc utility is running in channel mode, there is no start command, and the restart command just tells the name server to execvp(2) itself.