2013-03-14ISCInternet Systems Consortium, Inc.rndc.conf5BIND9rndc.confrndc configuration file20002001200420052007201320142015201620182019Internet Systems Consortium, Inc. ("ISC")rndc.confDESCRIPTIONrndc.conf is the configuration file
for rndc, the BIND 9 name server control
utility. This file has a similar structure and syntax to
named.conf. 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:
C style: /* */
C++ style: // to end of line
Unix style: # to end of line
rndc.conf is much simpler than
named.conf. The file uses three
statements: an options statement, a server statement
and a key statement.
The statement contains five clauses.
The 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
rndc. The
clause is followed by the name of a key which is identified by
a statement. If no
is provided on the rndc command line,
and no clause is found in a matching
statement, this default key will be
used to authenticate the server's commands and responses. The
clause is followed by the port
to connect to on the remote name server. If no
option is provided on the rndc command
line, and no clause is found in a
matching statement, this default port
will be used to connect.
The and
clauses which
can be used to set the IPv4 and IPv6 source addresses
respectively.
After the keyword, the server
statement includes a string which is the hostname or address
for a name server. The statement has three possible clauses:
, and
. 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
clause is supplied these addresses will be used instead of
the server name. Each address can take an optional port.
If an or
of supplied then these will be used to specify the IPv4 and IPv6
source addresses respectively.
The statement begins with an identifying
string, the name of the key. The statement has two clauses.
identifies the authentication algorithm
for rndc 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.
There are two common ways to generate the base-64 string for the
secret. The BIND 9 program rndc-confgen
can
be used to generate a random key, or the
mmencode program, also known as
mimencode, can be used to generate a
base-64
string from known input. mmencode does
not
ship with BIND 9 but is available on many systems. See the
EXAMPLE section for sample command lines for each.
EXAMPLE
options {
default-server localhost;
default-key samplekey;
};
server localhost {
key samplekey;
};
server testserver {
key testkey;
addresses { localhost port 5353; };
};
key samplekey {
algorithm hmac-sha256;
secret "6FMfj43Osz4lyb24OIe2iGEz9lf1llJO+lz";
};
key testkey {
algorithm hmac-sha256;
secret "R3HI8P6BKw9ZwXwN3VZKuQ==";
};
In the above example, rndc 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.
If rndc -s testserver is used then rndc will
connect to server on localhost port 5353 using the key testkey.
To generate a random secret with rndc-confgen:
rndc-confgen
A complete rndc.conf file, including
the
randomly generated key, will be written to the standard
output. Commented-out and
statements for
named.conf are also printed.
To generate a base-64 secret with mmencode:
echo "known plaintext for a secret" | mmencodeNAME SERVER CONFIGURATION
The name server must be configured to accept rndc connections and
to recognize the key specified in the rndc.conf
file, using the controls statement in named.conf.
See the sections on the statement in the
BIND 9 Administrator Reference Manual for details.
SEE ALSOrndc8,
rndc-confgen8,
mmencode1,
BIND 9 Administrator Reference Manual.