<refentry xmlns:db="http://docbook.org/ns/docbook" version="5.0" xml:id="man.rndc.conf">

<info>

<date>2013-03-14</date>

</info>

<refentryinfo>

<corpname>ISC</corpname>

<corpauthor>Internet Systems Consortium, Inc.</corpauthor>

</refentryinfo>

<refmeta>

<refentrytitle><filename>rndc.conf</filename></refentrytitle>

<manvolnum>5</manvolnum>

<refmiscinfo>BIND9</refmiscinfo>

</refmeta>

<refnamediv>

<refname><filename>rndc.conf</filename></refname>

<refpurpose>rndc configuration file</refpurpose>

</refnamediv>

<docinfo>

<copyright>

<year>2000</year>

<year>2001</year>

<year>2004</year>

<year>2005</year>

<year>2007</year>

<year>2013</year>

<year>2014</year>

<year>2015</year>

<year>2016</year>

<holder>Internet Systems Consortium, Inc. ("ISC")</holder>

</copyright>

</docinfo>

<refsynopsisdiv>

<cmdsynopsis sepchar=" ">

<command>rndc.conf</command>

</cmdsynopsis>

</refsynopsisdiv>

<refsection><info><title>DESCRIPTION</title></info>

<para><filename>rndc.conf</filename> is the configuration file

for <command>rndc</command>, the BIND 9 name server control

utility. This file has a similar structure and syntax to

<filename>named.conf</filename>. Statements are enclosed

in braces and terminated with a semi-colon. Clauses in

the statements are also semi-colon terminated. The usual

comment styles are supported:

</para>

<para>

C style: /* */

</para>

<para>

C++ style: // to end of line

</para>

<para>

Unix style: # to end of line

</para>

<para><filename>rndc.conf</filename> is much simpler than

<filename>named.conf</filename>. The file uses three

statements: an options statement, a server statement

and a key statement.

</para>

<para>

The <option>options</option> statement contains five clauses.

The <option>default-server</option> clause is followed by the

name or address of a name server. This host will be used when

no name server is given as an argument to

<command>rndc</command>. The <option>default-key</option>

clause is followed by the name of a key which is identified by

a <option>key</option> statement. If no

<option>keyid</option> is provided on the rndc command line,

and no <option>key</option> clause is found in a matching

<option>server</option> statement, this default key will be

used to authenticate the server's commands and responses. The

<option>default-port</option> clause is followed by the port

to connect to on the remote name server. If no

<option>port</option> option is provided on the rndc command

line, and no <option>port</option> clause is found in a

matching <option>server</option> statement, this default port

will be used to connect.

The <option>default-source-address</option> and

<option>default-source-address-v6</option> clauses which

can be used to set the IPv4 and IPv6 source addresses

respectively.

</para>

<para>

After the <option>server</option> keyword, the server

statement includes a string which is the hostname or address

for a name server. The statement has three possible clauses:

<option>key</option>, <option>port</option> and

<option>addresses</option>. The key name must match the

name of a key statement in the file. The port number

specifies the port to connect to. If an <option>addresses</option>

clause is supplied these addresses will be used instead of

the server name. Each address can take an optional port.

If an <option>source-address</option> or <option>source-address-v6</option>

of supplied then these will be used to specify the IPv4 and IPv6

source addresses respectively.

</para>

<para>

The <option>key</option> statement begins with an identifying

string, the name of the key. The statement has two clauses.

<option>algorithm</option> identifies the authentication algorithm

for <command>rndc</command> to use; currently only HMAC-MD5

(for compatibility), HMAC-SHA1, HMAC-SHA224, HMAC-SHA256

(default), HMAC-SHA384 and HMAC-SHA512 are

supported. This is followed by a secret clause which contains

the base-64 encoding of the algorithm's authentication key. The

base-64 string is enclosed in double quotes.

</para>

<para>

There are two common ways to generate the base-64 string for the

secret. The BIND 9 program <command>rndc-confgen</command>

can

be used to generate a random key, or the

<command>mmencode</command> program, also known as

<command>mimencode</command>, can be used to generate a

base-64

string from known input. <command>mmencode</command> does

not

ship with BIND 9 but is available on many systems. See the

EXAMPLE section for sample command lines for each.

</para>

</refsection>

<refsection><info><title>EXAMPLE</title></info>

<para><programlisting>

options {

default-server localhost;

default-key samplekey;

};

</programlisting>

</para>

<para><programlisting>

server localhost {

key samplekey;

};

</programlisting>

</para>

<para><programlisting>

server testserver {

key testkey;

addresses { localhost port 5353; };

};

</programlisting>

</para>

<para><programlisting>

key samplekey {

algorithm hmac-sha256;

secret "6FMfj43Osz4lyb24OIe2iGEz9lf1llJO+lz";

};

</programlisting>

</para>

<para><programlisting>

key testkey {

algorithm hmac-sha256;

secret "R3HI8P6BKw9ZwXwN3VZKuQ==";

};

</programlisting>

</para>

<para>

In the above example, <command>rndc</command> will by

default use

the server at localhost (127.0.0.1) and the key called samplekey.

Commands to the localhost server will use the samplekey key, which

must also be defined in the server's configuration file with the

same name and secret. The key statement indicates that samplekey

uses the HMAC-SHA256 algorithm and its secret clause contains the

base-64 encoding of the HMAC-SHA256 secret enclosed in double quotes.

</para>

<para>

If <command>rndc -s testserver</command> is used then <command>rndc</command> will

connect to server on localhost port 5353 using the key testkey.

</para>

<para>

To generate a random secret with <command>rndc-confgen</command>:

</para>

<para><userinput>rndc-confgen</userinput>

</para>

<para>

A complete <filename>rndc.conf</filename> file, including

the

randomly generated key, will be written to the standard

output. Commented-out <option>key</option> and

<option>controls</option> statements for

<filename>named.conf</filename> are also printed.

</para>

<para>

To generate a base-64 secret with <command>mmencode</command>:

</para>

<para><userinput>echo "known plaintext for a secret" | mmencode</userinput>

</para>

</refsection>

<refsection><info><title>NAME SERVER CONFIGURATION</title></info>

<para>

The name server must be configured to accept rndc connections and

to recognize the key specified in the <filename>rndc.conf</filename>

file, using the controls statement in <filename>named.conf</filename>.

See the sections on the <option>controls</option> statement in the

BIND 9 Administrator Reference Manual for details.

</para>

</refsection>

<refsection><info><title>SEE ALSO</title></info>

<para><citerefentry>

<refentrytitle>rndc</refentrytitle><manvolnum>8</manvolnum>

</citerefentry>,

<citerefentry>

<refentrytitle>rndc-confgen</refentrytitle><manvolnum>8</manvolnum>

</citerefentry>,

<citerefentry>

<refentrytitle>mmencode</refentrytitle><manvolnum>1</manvolnum>

</citerefentry>,

<citetitle>BIND 9 Administrator Reference Manual</citetitle>.

</para>

</refsection>

</refentry>