Skip site navigation (1)Skip section navigation (2)

FreeBSD Man Pages

Man Page or Keyword Search:
Man Architecture
Apropos Keyword Search (all sections) Output format
home | help
NAMED.CONF(5)		  FreeBSD File Formats Manual		 NAMED.CONF(5)

NAME
     named.conf	-- configuration file for named(8)

OVERVIEW
     BIND 8 is much more configurable than previous release of BIND.  There
     are entirely new areas of configuration, such as access control lists and
     categorized logging.  Many	options	that previously	applied	to all zones
     can now be	used selectively.  These features, plus	a consideration	of
     future configuration needs	led to the creation of a new configuration
     file format.

   General Syntax
     A BIND 8 configuration consists of	two general features, statements and
     comments.	All statements end with	a semicolon.  Many statements can con-
     tain substatements, which are each	also terminated	with a semicolon.

     The following statements are supported:

     logging
       specifies what the server logs, and where the log messages are sent

     options
       controls	global server configuration options and	sets defaults for
       other statements

     zone
       defines a zone

     acl
       defines a named IP address matching list, for access control and	other
       uses

     key
       specifies key information for use in authentication and authorization

     trusted-keys
       defines DNSSEC keys that	are preconfigured into the server and implic-
       itly trusted

     server
       sets certain configuration options for individual remote	servers

     controls
       declares	control	channels to be used by the ndc utility

     include
       includes	another	file

     The logging and options statements	may only occur once per	configuration,
     while the rest may	appear numerous	times.	Further	detail on each state-
     ment is provided in individual sections below.

     Comments may appear anywhere that whitespace may appear in	a BIND config-
     uration file.  To appeal to programmers of	all kinds, they	can be written
     in	C, C++,	or shell/perl constructs.

     C-style comments start with the two characters /* (slash, star) and end
     with */ (star, slash).  Because they are completely delimited with	these
     characters, they can be used to comment only a portion of a line or to
     span multiple lines.

     C-style comments cannot be	nested.	 For example, the following is not
     valid because the entire comment ends with	the first */:

	   /* This is the start	of a comment.
	      This is still part of the	comment.
	   /* This is an incorrect attempt at nesting a	comment. */
	      This is no longer	in any comment.	*/

     C++-style comments	start with the two characters // (slash, slash)	and
     continue to the end of the	physical line.	They cannot be continued
     across multiple physical lines; to	have one logical comment span multiple
     lines, each line must use the // pair.  For example:

	   // This is the start	of a comment.  The next	line
	   // is a new comment,	even though it is logically
	   // part of the previous comment.

     Shell-style (or perl-style, if you	prefer)	comments start with the	char-
     acter # (hash or pound or number or octothorpe or whatever) and continue
     to	the end	of the physical	line, like C++ comments.  For example:

	   # This is the start of a comment.  The next line
	   # is	a new comment, even though it is logically
	   # part of the previous comment.

     WARNING: you cannot use the ; (semicolon) character to start a comment
     such as you would in a zone file.	The semicolon indicates	the end	of a
     configuration statement, so whatever follows it will be interpreted as
     the start of the next statement.

   Converting from BIND	4.9.x
     BIND 4.9.x	configuration files can	be converted to	the new	format by
     using src/bin/named/named-bootconf, a shell script	that is	part of	the
     BIND 8.2.x	source kit.

DOCUMENTATION DEFINITIONS
     Described below are elements used throughout the BIND configuration file
     documentation.  Elements which are	only associated	with one statement are
     described only in the section describing that statement.

     acl_name
       The name	of an address_match_list as defined by the acl statement.

     address_match_list
       A list of one or	more ip_addr, ip_prefix, key_id, or acl_name elements,
       as described in the ADDRESS MATCH LISTS section.

     dotted-decimal
       One or more integers valued 0 through 255 separated only	by dots
       (``.''),	such as	123, 45.67 or 89.123.45.67.

     domain_name
       A quoted	string which will be used as a DNS name, for example
       "my.test.domain".

     path_name
       A quoted	string which will be used as a pathname, such as
       "zones/master/my.test.domain".

     ip_addr
       An IP address with exactly four elements	in dotted-decimal notation.

     ip_port
       An IP port number.  number is limited to	0 through 65535, with values
       below 1024 typically restricted to root-owned processes.	 In some cases
       an asterisk (``*'') character can be used as a placeholder to select a
       random high-numbered port.

     ip_prefix
       An IP network specified in dotted-decimal form, followed	by  ``/'' and
       then the	number of bits in the netmask.	E.g.  127/8 is the network
       127.0.0.0 with netmask 255.0.0.0.  1.2.3.0/28 is	network	1.2.3.0	with
       netmask 255.255.255.240.

     key_name
       A string	representing the name of a shared key, to be used for transac-
       tion security.

     number
       A non-negative integer with an entire range limited by the range	of a C
       language	signed integer (2,147,483,647 on a machine with	32 bit inte-
       gers).  Its acceptable value might further be limited by	the context in
       which it	is used.

     size_spec
       A number, the word unlimited, or	the word default.

       The maximum value of size_spec is that of unsigned long integers	on the
       machine.	 unlimited requests unlimited use, or the maximum available
       amount.	default	uses the limit that was	in force when the server was
       started.

       A number	can optionally be followed by a	scaling	factor:	K or k for
       kilobytes, M or m for megabytes,	and G or g for gigabytes, which	scale
       by 1024,	1024*1024, and 1024*1024*1024 respectively.

       Integer storage overflow	is currently silently ignored during conver-
       sion of scaled values, resulting	in values less than intended, possibly
       even negative.  Using unlimited is the best way to safely set a really
       large number.

     yes_or_no
       Either yes or no.  The words true and false are also accepted, as are
       the numbers 1 and 0.

ADDRESS	MATCH LISTS
   Syntax
     address_match_list	   = 1*address_match_element

     address_match_element = [ "!" ] ( address_match_list /
				       ip_address / ip_prefix /
				       acl_name	/ "key " key_id	) ";"

   Definition and Usage
     Address match lists are primarily used to determine access	control	for
     various server operations.	 They are also used to define priorities for
     querying other nameservers	and to set the addresses on which named	will
     listen for	queries.  The elements which constitute	an address match list
     can be any	of the following:

     +o	 an ip-address (in dotted-decimal notation,

     +o	 an ip-prefix (in the '/'-notation),

     +o	 A key_id, as defined by the key statement,

     +o	 the name of an	address	match list previously defined with the acl
	 statement, or

     +o	 another address_match_list.

     Elements can be negated with a leading exclamation	mark (``!''), and the
     match list	names any, none, localhost and localnets are predefined.  More
     information on those names	can be found in	the description	of the acl
     statement.

     The addition of the key clause made the name of this syntactic element
     something of a misnomer, since security keys can be used to validate
     access without regard to a	host or	network	address.  Nonetheless, the
     term ``address match list'' is still used throughout the documentation.

     When a given IP address or	prefix is compared to an address match list,
     the list is traversed in order until an element matches.  The interpreta-
     tion of a match depends on	whether	the list is being used for access con-
     trol, defining listen-on ports, or	as a topology, and whether the element
     was negated.

     When used as an access control list, a non-negated	match allows access
     and a negated match denies	access.	 If there is no	match at all in	the
     list, access is denied.  The clauses allow-query, allow-transfer,
     allow-update, allow-recursion, and	blackhole all use address match	lists
     like this.	 Similarly, the	listen-on option will cause the	server to not
     accept queries on any of the machine's addresses which do not match the
     list.

     When used with the	topology option, a non-negated match returns a dis-
     tance based on its	position on the	list (the closer the match is to the
     start of the list,	the shorter the	distance is between it and the
     server).  A negated match will be assigned	the maximum distance from the
     server.  If there is no match, the	address	will get a distance which is
     further than any non-negated list element,	and closer than	any negated
     element.

     Because of	the first-match	aspect of the algorithm, an element that
     defines a subset of another element in the	list should come before	the
     broader element, regardless of whether either is negated.	For example,
     in
	   1.2.3/24; !1.2.3.13
     the 1.2.3.13 element is completely	useless, because the algorithm will
     match any lookup for 1.2.3.13 to the 1.2.3/24 element.  Using
	   !1.2.3.13; 1.2.3/24
     fixes that	problem	by having 1.2.3.13 blocked by the negation but all
     other 1.2.3.* hosts fall through.

THE LOGGING STATEMENT
   Syntax
     logging {
       [ channel channel_name {
	 ( file	path_name
	    [ versions ( number	| unlimited ) ]
	    [ size size_spec ]
	  | syslog ( kern | user | mail	| daemon | auth	| syslog | lpr |
		     news | uucp | cron	| authpriv | ftp |
		     local0 | local1 | local2 |	local3 |
		     local4 | local5 | local6 |	local7 )
	  | null );

	 [ severity ( critical | error | warning | notice |
		      info  | debug [ level ] |	dynamic	); ]
	 [ print-category yes_or_no; ]
	 [ print-severity yes_or_no; ]
	 [ print-time yes_or_no; ]
       }; ]

       [ category category_name	{
	 channel_name; [ channel_name; ... ]
       }; ]
       ...
     };

   Definition and Usage
     The logging statement configures a	wide variety of	logging	options	for
     the nameserver.  Its channel phrase associates output methods, format
     options and severity levels with a	name that can then be used with	the
     category phrase to	select how various classes of messages are logged.

     Only one logging statement	is used	to define as many channels and cate-
     gories as are wanted.  If there are multiple logging statements in	a con-
     figuration, the first defined determines the logging, and warnings	are
     issued for	the others.  If	there is no logging statement, the logging
     configuration will	be:

	 logging {
	     category default {	default_syslog;	default_debug; };
	     category panic { default_syslog; default_stderr; };
	     category packet { default_debug; };
	     category eventlib { default_debug;	};
	 };

     The logging configuration is established as soon as the logging statement
     is	parsed.	 If you	want to	redirect messages about	processing of the
     entire configuration file,	the logging statement must appear first.  Even
     if	you do not redirect configuration file parsing messages, we recommend
     always putting the	logging	statement first	so that	this rule need not be
     consciously recalled if you ever do want the parser's messages relocated.

   The channel phrase
     All log output goes to one	or more	``channels''; you can make as many of
     them as you want.

     Every channel definition must include a clause that says whether messages
     selected for the channel go to a file, to a particular syslog facility,
     or	are discarded.	It can optionally also limit the message severity
     level that	will be	accepted by the	channel	(default is info), and whether
     to	include	a time stamp generated by named, the category name, or sever-
     ity level.	 The default is	not to include any of those three.

     The word null as the destination option for the channel will cause	all
     messages sent to it to be discarded; other	options	for the	channel	are
     meaningless.

     The file clause can include limitations both on how large the file	is
     allowed to	become,	and how	many versions of the file will be saved	each
     time the file is opened.

     The size option for files is simply a hard	ceiling	on log growth.	If the
     file ever exceeds the size, then named will just not write	anything more
     to	it until the file is reopened; exceeding the size does not automati-
     cally trigger a reopen.  The default behavior is to not limit the size of
     the file.

     If	you use	the version logfile option, then named will retain that	many
     backup versions of	the file by renaming them when opening.	 For example,
     if	you choose to keep 3 old versions of the file lamers.log then just
     before it is opened lamers.log.1 is renamed to lames.log.2, lamers.log.0
     is	renamed	to lamers.log.1, and lamers.log	is renamed to lamers.log.0.
     No	rolled versions	are kept by default; any existing log file is simply
     appended.	The unlimited keyword is synonymous with 99 in current BIND
     releases.	Example	usage of size and versions options:

	 channel an_example_level {
	     file "lamers.log" versions	3 size 20m;
	     print-time	yes;
	     print-category yes;
	 };

     The argument for the syslog clause	is a syslog facility as	described in
     the syslog(3) manual page.	 How syslogd will handle messages sent to this
     facility is described in the syslog.conf(5) manual	page.  If you have a
     system which uses a very old version of syslog that only uses two argu-
     ments to the openlog() function, then this	clause is silently ignored.

     The severity clause works like syslog's ``priorities'', except that they
     can also be used if you are writing straight to a file rather than	using
     syslog.  Messages	which are not at least of the severity level given
     will not be selected for the channel; messages of higher severity levels
     will be accepted.

     If	you are	using syslog, then the syslog.conf priorities will also	deter-
     mine what eventually passes through.  For example,	defining a channel
     facility and severity as daemon and debug but only	logging	daemon.warning
     via syslog.conf will cause	messages of severity info and notice to	be
     dropped.  If the situation	were reversed, with named writing messages of
     only warning or higher, then syslogd would	print all messages it received
     from the channel.

     The server	can supply extensive debugging information when	it is in
     debugging mode.  If the server's global debug level is greater than zero,
     then debugging mode will be active.  The global debug level is set	either
     by	starting the named server with the -d flag followed by a positive
     integer, or by sending the	running	server the SIGUSR1 signal (for exam-
     ple, by using ndc trace).	The global debug level can be set to zero, and
     debugging mode turned off,	by sending the server the SIGUSR2 signal (as
     with ndc notrace).	 All debugging messages	in the server have a debug
     level, and	higher debug levels give more more detailed output.  Channels
     that specify a specific debug severity, e.g.

	 channel specific_debug_level {
	     file "foo";
	     severity debug 3;
	 };

     will get debugging	output of level	3 or less any time the server is in
     debugging mode, regardless	of the global debugging	level.	Channels with
     dynamic severity use the server's global level to determine what messages
     to	print.

     If	print-time has been turned on, then the	date and time will be logged.
     print-time	may be specified for a syslog channel, but is usually point-
     less since	syslog also prints the date and	time.  If print-category is
     requested,	then the category of the message will be logged	as well.
     Finally, if print-severity	is on, then the	severity level of the message
     will be logged.  The print- options may be	used in	any combination, and
     will always be printed in the following order: time, category, severity.
     Here is an	example	where all three	print- options are on:

	 28-Apr-1997 15:05:32.863 default: notice: Ready to answer queries.

     There are four predefined channels	that are used for default logging as
     follows.  How they	are used used is described in the next section,	The
     category phrase.

	 channel default_syslog	{
	     syslog daemon;	  # send to syslog's daemon facility
	     severity info;	  # only send priority info and	higher
	 };

	 channel default_debug {
	     file "named.run";	  # write to named.run in the working directory
				  # Note: stderr is used instead of "named.run"
				  # if the server is started with the -f option.
	     severity dynamic;	  # log	at the server's	current	debug level
	 };

	 channel default_stderr	{ # writes to stderr
	     file "<stderr>";	  # this is illustrative only; there's currently
				  # no way of specifying an internal file
				  # descriptor in the configuration language.
	     severity info;	  # only send priority info and	higher
	 };

	 channel null {
	     null;		  # toss anything sent to this channel
	 };

     Once a channel is defined,	it cannot be redefined.	 Thus you cannot alter
     the built-in channels directly, but you can modify	the default logging by
     pointing categories at channels you have defined.

   The category	phrase
     There are many categories,	so you can send	the logs you want to see wher-
     ever you want, without seeing logs	you don't want.	 If you	don't specify
     a list of channels	for a category,	then log messages in that category
     will be sent to the default category instead.  If you don't specify a
     default category, the following ``default default'' is used:

	 category default { default_syslog; default_debug; };

     As	an example, let's say you want to log security events to a file, but
     you also want keep	the default logging behavior.  You'd specify the fol-
     lowing:

	 channel my_security_channel {
	     file "my_security_file";
	     severity info;
	 };
	 category security { my_security_channel;
			     default_syslog; default_debug; };

     To	discard	all messages in	a category, specify the	null channel:

	 category lame-servers { null; };
	 category cname	{ null;	};

     The following categories are available:

     default
       The catch-all.  Many things still aren't	classified into	categories,
       and they	all end	up here.  Also,	if you don't specify any channels for
       a category, the default category	is used	instead.  If you do not	define
       the default category, the following definition is used:
	     category default {	default_syslog;	default_debug; };

     config
       High-level configuration	file processing.

     parser
       Low-level configuration file processing.

     queries
       A short log message is generated	for every query	the server receives.

     lame-servers
       Messages	like ``Lame server on ...''

     statistics
       Statistics.

     panic
       If the server has to shut itself	down due to an internal	problem, it
       will log	the problem in this category as	well as	in the problem's
       native category.	 If you	do not define the panic	category, the follow-
       ing definition is used:
	     category panic { default_syslog; default_stderr; };

     update
       Dynamic updates.

     update-security
       Denied dynamic updates due to access controls.

     ncache
       Negative	caching.

     xfer-in
       Zone transfers the server is receiving.

     xfer-out
       Zone transfers the server is sending.

     db
       All database operations.

     eventlib
       Debugging info from the event system.  Only one channel may be speci-
       fied for	this category, and it must be a	file channel.  If you do not
       define the eventlib category, the following definition is used:
	     category eventlib { default_debug;	};

     packet
       Dumps of	packets	received and sent.  Only one channel may be specified
       for this	category, and it must be a file	channel.  If you do not	define
       the packet category, the	following definition is	used:
	     category packet { default_debug; };

     notify
       The NOTIFY protocol.

     cname
       Messages	like ``... points to a CNAME''.

     security
       Approved/unapproved requests.

     os
       Operating system	problems.

     insist
       Internal	consistency check failures.

     maintenance
       Periodic	maintenance events.

     load
       Zone loading messages.

     response-checks
       Messages	arising	from response checking,	such as	``Malformed response
       ...'', ``wrong ans. name	...'', ``unrelated additional info ...'',
       ``invalid RR type ...'',	and ``bad referral ...''.

THE OPTIONS STATEMENT
   Syntax
     options {
       [ hostname hostname_string; ]
       [ version version_string; ]
       [ directory path_name; ]
       [ named-xfer path_name; ]
       [ dump-file path_name; ]
       [ memstatistics-file path_name; ]
       [ pid-file path_name; ]
       [ statistics-file path_name; ]
       [ auth-nxdomain yes_or_no; ]
       [ deallocate-on-exit yes_or_no; ]
       [ dialup	yes_or_no; ]
       [ fake-iquery yes_or_no;	]
       [ fetch-glue yes_or_no; ]
       [ has-old-clients yes_or_no; ]
       [ host-statistics yes_or_no; ]
       [ host-statistics-max number; ]
       [ multiple-cnames yes_or_no; ]
       [ notify	( yes_or_no | explicit ); ]
       [ suppress-initial-notify yes_or_no; ]
       [ recursion yes_or_no; ]
       [ rfc2308-type1 yes_or_no; ]
       [ use-id-pool yes_or_no;	]
       [ treat-cr-as-space yes_or_no; ]
       [ also-notify yes_or_no;	]
       [ forward ( only	| first	); ]
       [ forwarders { [	in_addr	; [ in_addr ; ... ] ] }; ]
       [ check-names ( master |	slave |	response ) ( warn | fail | ignore ); ]
       [ allow-query { address_match_list }; ]
       [ allow-recursion { address_match_list }; ]
       [ allow-transfer	{ address_match_list };	]
       [ blackhole { address_match_list	}; ]
       [ listen-on [ port ip_port ] { address_match_list }; ]
       [ query-source [	address	( ip_addr | * )	]
		      [	port ( ip_port | * ) ] ; ]
       [ lame-ttl number; ]
       [ max-transfer-time-in number; ]
       [ max-ncache-ttl	number;	]
       [ min-roots number; ]
       [ serial-queries	number;	]
       [ transfer-format ( one-answer |	many-answers );	]
       [ transfers-in  number; ]
       [ transfers-out number; ]
       [ transfers-per-ns number; ]
       [ transfer-source ip_addr; ]
       [ maintain-ixfr-base yes_or_no; ]
       [ max-ixfr-log-size number; ]
       [ coresize size_spec ; ]
       [ datasize size_spec ; ]
       [ files size_spec ; ]
       [ stacksize size_spec ; ]
       [ cleaning-interval number; ]
       [ heartbeat-interval number; ]
       [ interface-interval number; ]
       [ statistics-interval number; ]
       [ topology { address_match_list }; ]
       [ sortlist { address_match_list }; ]
       [ rrset-order { order_spec ; [ order_spec ; ... ] }; ]
       [ preferred-glue	( A | AAAA ); ]
       [ edns-udp-size number; ]
     };

   Definition and Usage
     The options statement sets	up global options to be	used by	BIND. This
     statement may appear at only once in a configuration file;	if more	than
     one occurrence is found, the first	occurrence determines the actual
     options used, and a warning will be generated.  If	there is no options
     statement,	an options block with each option set to its default will be
     used.

   Server Information
     hostname
       This defaults to	the hostname of	the machine hosting the	nameserver as
       found by	gethostname().	Its prime purpose is to	be able	to identify
       which of	a number of anycast servers is actually	answering your queries
       by sending a txt	query for hostname.bind	in class chaos to the anycast
       server and geting back a	unique name.  Setting the hostname to a	empty
       string ("") will	disable	processing of the queries.

     version
       The version the server should report via	the ndc	command	or via a query
       of name version.bind in class chaos.  The default is the	real version
       number of the server, but some server operators prefer the string (
       surely you must be joking ).

   Pathnames
     directory
       The working directory of	the server.  Any non-absolute pathnames	in the
       configuration file will be taken	as relative to this directory.	The
       default location	for most server	output files (e.g.  named.run) is this
       directory.  If a	directory is not specified, the	working	directory
       defaults	to ., the directory from which the server was started.	The
       directory specified should be an	absolute path.

     named-xfer
       The pathname to the named-xfer program that the server uses for inbound
       zone transfers.	If not specified, the default is system	dependent
       (e.g.  /usr/sbin/named-xfer ).

     dump-file
       The pathname of the file	the server dumps the database to when it
       receives	SIGINT signal (as sent by ndc dumpdb ).	If not specified, the
       default is named_dump.db.

     memstatistics-file
       The pathname of the file	the server writes memory usage statistics to
       on exit,	if deallocate-on-exit is yes.  If not specified, the default
       is named.memstats.

     pid-file
       The pathname of the file	the server writes its process ID in.  If not
       specified, the default is operating system dependent, but is usually
       /var/run/named.pid or /etc/named.pid.  The pid-file is used by programs
       like ndc	that want to send signals to the running nameserver.

     statistics-file
       The pathname of the file	the server appends statistics to when it
       receives	SIGILL signal (from ndc	stats).	 If not	specified, the default
       is named.stats.

   Boolean Options
     auth-nxdomain
       If yes, then the	AA bit is always set on	NXDOMAIN responses, even if
       the server is not actually authoritative.  The default is no.  Turning
       will allow older	clients	that require AA	to be set to accept NXDOMAIN
       responses to work.

     deallocate-on-exit
       If yes, then when the server exits it will painstakingly	deallocate
       every object it allocated, and then write a memory usage	report to the
       memstatistics-file.  The	default	is no, because it is faster to let the
       operating system	clean up.  deallocate-on-exit is handy for detecting
       memory leaks.

     dialup
       If yes, then the	server treats all zones	as if they are doing zone
       transfers across	a dial on demand dialup	link, which can	be brought up
       by traffic originating from this	server.	 This has different effects
       according to zone type and concentrates the zone	maintenance so that it
       all happens in a	short interval,	once every heartbeat-interval and
       hopefully during	the one	call.  It also suppresses some of the normal
       zone maintenance	traffic.  The default is no.  The dialup option	may
       also be specified in the	zone statement,	in which case it overrides the
       options dialup statement.

       If the zone is a	master then the	server will send out NOTIFY request to
       all the slaves.	This will trigger the zone up to date checking in the
       slave (providing	it supports NOTIFY) allowing  the slave	to verify the
       zone while the call us up.

       If the zone is a	slave or stub then the server will suppress the	zone
       regular zone up to date queries and only	perform	the when the
       heartbeat-interval expires.

     fake-iquery
       If yes, the server will simulate	the obsolete DNS query type IQUERY.
       The default is no.

     fetch-glue
       If yes (the default), the server	will fetch ``glue'' resource records
       it doesn't have when constructing the additional	data section of	a
       response.  fetch-glue no	can be used in conjunction with	recursion no
       to prevent the server's cache from growing or becoming corrupted	(at
       the cost	of requiring more work from the	client).

     has-old-clients
       Setting the option to yes, is equivalent	to setting the following three
       options:	auth-nxdomain yes;, maintain-ixfr-base yes;, and rfc2308-type1
       no;

       The use of has-old-clients with auth-nxdomain, maintain-ixfr-base, and
       rfc2308-type1 is	order dependent.

     host-statistics
       If yes, then statistics are kept	for every host that the	the nameserver
       interacts with.	The default is no.  Note: turning on host-statistics
       can consume huge	amounts	of memory.

     maintain-ixfr-base
       If yes, a IXFR database file is kept for	all dynamically	updated	zones.
       This enables the	server to answer IXFR queries which can	speed up zone
       transfers enormously.  The default is no.

     multiple-cnames
       If yes, then multiple CNAME resource records will be allowed for	a
       domain name.  The default is no.	 Allowing multiple CNAME records is
       against standards and is	not recommended.  Multiple CNAME support is
       available because previous versions of BIND allowed multiple CNAME
       records,	and these records have been used for load balancing by a num-
       ber of sites.

     notify
       If yes (the default), DNS NOTIFY	messages are sent when a zone the
       server is authoritative for changes.  The use of	NOTIFY speeds conver-
       gence between the master	and its	slaves.	 Slave servers that receive a
       NOTIFY message and understand it	will contact the master	server for the
       zone and	see if they need to do a zone transfer,	and if they do,	they
       will initiate it	immediately.  If explicit, the DNS NOTIFY messages
       will only be sent to the	addresses in the also-notify list.  The	notify
       option may also be specified in the zone	statement, in which case it
       overrides the options notify statement.

     suppress-initial-notify
       If yes, suppress	the initial notify messages when the server first
       loads.  The default is no.

     recursion
       If yes, and a DNS query requests	recursion, then	the server will
       attempt to do all the work required to answer the query.	 If recursion
       is not on, the server will return a referral to the client if it
       doesn't know the	answer.	 The default is	yes.  See also fetch-glue
       above.

     rfc2308-type1
       If yes, the server will send NS records along with the SOA record for
       negative	answers.  You need to set this to no if	you have an old	BIND
       server using you	as a forwarder that does not understand	negative
       answers which contain both SOA and NS records or	you have an old	ver-
       sion of sendmail.  The correct fix is to	upgrade	the broken server or
       sendmail.  The default is no.

     use-id-pool
       If yes, the server will keep track of its own outstanding query ID's to
       avoid duplication and increase randomness.  This	will result in 128KB
       more memory being consumed by the server.  The default is no.

     treat-cr-as-space
       If yes, the server will treat CR	characters the same way	it treats a
       space or	tab.  This may be necessary when loading zone files on a UNIX
       system that were	generated on an	NT or DOS machine.  The	default	is no.

   Also-Notify
     also-notify

     Defines a global list of IP addresses that	also get sent NOTIFY messages
     whenever a	fresh copy of the zone is loaded. This helps to	ensure that
     copies of the zones will quickly converge on ``stealth'' servers.	If an
     also-notify list is given in a zone statement, it will override the
     options also-notify statement. When a zone	notify statement is set	to no,
     the IP addresses in the global also-notify	list will not get sent NOTIFY
     messages for that zone.  The default is the empty list (no	global notifi-
     cation list).

   Forwarding
     The forwarding facility can be used to create a large site-wide cache on
     a few servers, reducing traffic over links	to external nameservers.  It
     can also be used to allow queries by servers that do not have direct
     access to the Internet, but wish to look up exterior names	anyway.	 For-
     warding occurs only on those queries for which the	server is not authori-
     tative and	does not have the answer in its	cache.

     forward
       This option is only meaningful if the forwarders	list is	not empty.  A
       value of	first, the default, causes the server to query the forwarders
       first, and if that doesn't answer the question the server will then
       look for	the answer itself.  If only is specified, the server will only
       query the forwarders.

     forwarders
       Specifies the IP	addresses to be	used for forwarding.  The default is
       the empty list (no forwarding).

     Forwarding	can also be configured on a per-zone basis, allowing for the
     global forwarding options to be overridden	in a variety of	ways.  You can
     set particular zones to use different forwarders, or have different
     forward only/first	behavior, or to	not forward at all.  See THE ZONE
     STATEMENT section for more	information.

     Future versions of	BIND 8 will provide a more powerful forwarding system.
     The syntax	described above	will continue to be supported.

   Name	Checking
     The server	can check domain names based upon their	expected client	con-
     texts.  For example, a domain name	used as	a hostname can be checked for
     compliance	with the RFCs defining valid hostnames.

     Three checking methods are	available:

     ignore
       No checking is done.

     warn
       Names are checked against their expected	client contexts.  Invalid
       names are logged, but processing	continues normally.

     fail
       Names are checked against their expected	client contexts.  Invalid
       names are logged, and the offending data	is rejected.

     The server	can check names	three areas: master zone files,	slave zone
     files, and	in responses to	queries	the server has initiated.  If
     check-names response fail has been	specified, and answering the client's
     question would require sending an invalid name to the client, the server
     will send a REFUSED response code to the client.

     The defaults are:

	 check-names master fail;
	 check-names slave warn;
	 check-names response ignore;

     check-names may also be specified in the zone statement, in which case it
     overrides the options check-names statement.  When	used in	a zone state-
     ment, the area is not specified (because it can be	deduced	from the zone
     type).

   Access Control
     Access to the server can be restricted based on the IP address of the
     requesting	system or via shared secret keys.  See ADDRESS MATCH LISTS for
     details on	how to specify access criteria.

     allow-query
       Specifies which hosts are allowed to ask	ordinary questions.
       allow-query may also be specified in the	zone statement,	in which case
       it overrides the	options	allow-query statement.	If not specified, the
       default is to allow queries from	all hosts.

       allow-recursion
	 Specifies which hosts are allowed to ask recursive questions.	If not
	 specified, the	default	is to allow recursive queries from all hosts.

       allow-transfer
	 Specifies which hosts are allowed to receive zone transfers from the
	 server.  allow-transfer may also be specified in the zone statement,
	 in which case it overrides the	options	allow-transfer statement.  If
	 not specified,	the default is to allow	transfers from all hosts.

       blackhole
	 Specifies a list of addresses that the	server will not	accept queries
	 from or use to	resolve	a query.  Queries from these addresses will
	 not be	responded to.

   Interfaces
     The interfaces and	ports that the server will answer queries from may be
     specified using the listen-on option.  listen-on takes an optional	port,
     and an address match list.	 The server will listen	on all interfaces
     allowed by	the address match list.	 If a port is not specified, port 53
     will be used.

     Multiple listen-on	statements are allowed.	 For example,

	 listen-on { 5.6.7.8; };
	 listen-on port	1234 { !1.2.3.4; 1.2/16; };

     will enable the nameserver	on port	53 for the IP address 5.6.7.8, and on
     port 1234 of an address on	the machine in net 1.2 that is not 1.2.3.4.

     If	no listen-on is	specified, the server will listen on port 53 on	all
     interfaces.

   Query Address
     If	the server doesn't know	the answer to a	question, it will query	other
     nameservers.  query-source	specifies the address and port used for	such
     queries.  If address is * or is omitted, a	wildcard IP address (
     INADDR_ANY) will be used.	If port	is * or	is omitted, a random unprivi-
     leged port	will be	used.  The default is
	   query-source	address	* port *;

     Note: query-source	currently applies only to UDP queries; TCP queries
     always use	a wildcard IP address and a random unprivileged	port.

   Zone	Transfers
     max-transfer-time-in
       Inbound zone transfers (	named-xfer processes) running longer than this
       many minutes will be terminated.	 The default is	120 minutes (2 hours).

     transfer-format
       The server supports two zone transfer methods.  one-answer uses one DNS
       message per resource record transferred.	 many-answers packs as many
       resource	records	as possible into a message.  many-answers is more
       efficient, but is only known to be understood by	BIND 8.1 and patched
       versions	of BIND	4.9.5.	The default is one-answer.  transfer-format
       may be overridden on a per-server basis by using	the server statement.

     transfers-in
       The maximum number of inbound zone transfers that can be	running	con-
       currently.  The default value is	10.  Increasing	transfers-in may speed
       up the convergence of slave zones, but it also may increase the load on
       the local system.

     transfers-out
       This option will	be used	in the future to limit the number of concur-
       rent outbound zone transfers.  It is checked for	syntax,	but is other-
       wise ignored.

     transfers-per-ns
       The maximum number of inbound zone transfers ( named-xfer processes)
       that can	be concurrently	transferring from a given remote nameserver.
       The default value is 2.	Increasing transfers-per-ns may	speed up the
       convergence of slave zones, but it also may increase the	load on	the
       remote nameserver.  transfers-per-ns may	be overridden on a per-server
       basis by	using the transfers phrase of the server statement.

     transfer-source
       transfer-source determines which	local address will be bound to the TCP
       connection used to fetch	all zones transferred inbound by the server.
       If not set, it defaults to a system controlled value which will usually
       be the address of the interface ``closest to`` the remote end.  This
       address must appear in the remote end's allow-transfer option for the
       zones being transferred,	if one is specified.  This statement sets the
       transfer-source for all zones, but can be overridden on a per-zone
       basis by	including a transfer-source statement within the zone block in
       the configuration file.

   Resource Limits
     The server's usage	of many	system resources can be	limited.  Some operat-
     ing systems don't support some of the limits.  On such systems, a warning
     will be issued if the unsupported limit is	used.  Some operating systems
     don't support limiting resources, and on these systems a
	   cannot set resource limits on this system
     message will be logged.

     Scaled values are allowed when specifying resource	limits.	 For example,
     1G	can be used instead of 1073741824 to specify a limit of	one gigabyte.
     unlimited requests	unlimited use, or the maximum available	amount.
     default uses the limit that was in	force when the server was started.
     See the definition	of size_spec in	the DOCUMENTATION DEFINITIONS section
     for more details.

     coresize
       The maximum size	of a core dump.	 The default value is default.

     datasize
       The maximum amount of data memory the server may	use.  The default
       value is	default.

     files
       The maximum number of files the server may have open concurrently.  The
       default value is	unlimited.  Note that on some operating	systems	the
       server cannot set an unlimited value and	cannot determine the maximum
       number of open files the	kernel can support.  On	such systems, choosing
       unlimited will cause the	server to use the larger of the	rlim_max from
       getrlimit(RLIMIT_NOFILE)	and the	value returned by
       sysconf(_SC_OPEN_MAX).  If the actual kernel limit is larger than this
       value, use limit	files to specify the limit explicitly.

     max-ixfr-log-size
       The max-ixfr-log-size will be used in a future release of the server to
       limit the size of the transaction log kept for Incremental Zone Trans-
       fer.

     stacksize
       The maximum amount of stack memory the server may use.  The default
       value is	default.

   Periodic Task Intervals
     cleaning-interval
       The server will remove expired resource records from the	cache every
       cleaning-interval minutes.  The default is 60 minutes.  If set to 0, no
       periodic	cleaning will occur.

     heartbeat-interval
       The server will perform zone maintenance	tasks for all zones marked
       dialup yes whenever this	interval expires.  The default is 60 minutes.
       Reasonable values are up	to 1 day (1440 minutes).  If set to 0, no zone
       maintenance for these zones will	occur.

     interface-interval
       The server will scan the	network	interface list every
       interface-interval minutes.  The	default	is 60 minutes.	If set to 0,
       interface scanning will only occur when the configuration file is
       loaded.	After the scan,	listeners will be started on any new inter-
       faces (provided they are	allowed	by the listen-on configuration).  Lis-
       teners on interfaces that have gone away	will be	cleaned	up.

     statistics-interval
       Nameserver statistics will be logged every statistics-interval minutes.
       The default is 60.  If set to 0,	no statistics will be logged.

   Topology
     All other things being equal, when	the server chooses a nameserver	to
     query from	a list of nameservers, it prefers the one that is topologi-
     cally closest to itself.  The topology statement takes an address match
     list and interprets it in a special way.  Each top-level list element is
     assigned a	distance.  Non-negated elements	get a distance based on	their
     position in the list, where the closer the	match is to the	start of the
     list, the shorter the distance is between it and the server.  A negated
     match will	be assigned the	maximum	distance from the server.  If there is
     no	match, the address will	get a distance which is	further	than any non-
     negated list element, and closer than any negated element.	 For example,

	 topology {
	     10/8;
	     !1.2.3/24;
	     { 1.2/16; 3/8; };
	 };

     will prefer servers on network 10 the most, followed by hosts on network
     1.2.0.0 (netmask 255.255.0.0) and network 3, with the exception of	hosts
     on	network	1.2.3 (netmask 255.255.255.0), which is	preferred least	of
     all.

     The default topology is
	   topology { localhost; localnets; };

   Resource Record sorting
     When returning multiple RRs, the nameserver will normally return them in
     Round Robin, i.e. after each request, the first RR	is put to the end of
     the list.	As the order of	RRs is not defined, this should	not cause any
     problems.

     The client	resolver code should re-arrange	the RRs	as appropriate,	i.e.
     using any addresses on the	local net in preference	to other addresses.
     However, not all resolvers	can do this, or	are not	correctly configured.

     When a client is using a local server, the	sorting	can be performed in
     the server, based on the client's address.	This only requires configuring
     the nameservers, not all the clients.

     The sortlist statement takes an address match list	and interprets it even
     more specially than the topology statement	does.

     Each top level statement in the sortlist must itself be an	explicit
     address match list	with one or two	elements. The first element (which may
     be	an IP address, an IP prefix, an	ACL name or nested address match list)
     of	each top level list is checked against the source address of the query
     until a match is found.

     Once the source address of	the query has been matched, if the top level
     statement contains	only one element, the actual primitive element that
     matched the source	address	is used	to select the address in the response
     to	move to	the beginning of the response. If the statement	is a list of
     two elements, the second element is treated like the address match	list
     in	a topology statement. Each top level element is	assigned a distance
     and the address in	the response with the minimum distance is moved	to the
     beginning of the response.

     In	the following example, any queries received from any of	the addresses
     of	the host itself	will get responses preferring addresses	on any of the
     locally connected networks. Next most preferred are addresses on the
     192.168.1/24 network, and after that either the 192.168.2/24 or
     192.168.3/24 network with no preference shown between these two networks.
     Queries received from a host on the 192.168.1/24 network will prefer
     other addresses on	that network to	the 192.168.2/24 and 192.168.3/24 net-
     works. Queries received from a host on the	192.168.4/24 or	the
     192.168.5/24 network will only prefer other addresses on their directly
     connected networks.

     sortlist {
		{ localhost;	     //	IF   the local host
		  { localnets;	     //	THEN first fit on the
		    192.168.1/24;    //	     following nets
		    { 192,168.2/24; 192.168.3/24; }; };	};
		{ 192.168.1/24;	     //	IF   on	class C	192.168.1
		  { 192.168.1/24;    //	THEN use .1, or	.2 or .3
		    { 192.168.2/24; 192.168.3/24; }; };	};
		{ 192.168.2/24;	     //	IF   on	class C	192.168.2
		  { 192.168.2/24;    //	THEN use .2, or	.1 or .3
		    { 192.168.1/24; 192.168.3/24; }; };	};
		{ 192.168.3/24;	     //	IF   on	class C	192.168.3
		  { 192.168.3/24;    //	THEN use .3, or	.1 or .2
		    { 192.168.1/24; 192.168.2/24; }; };	};
		{ { 192.168.4/24; 192.168.5/24;	}; // if .4 or .5, prefer that net
		};
     };

     The following example will	give reasonable	behaviour for the local	host
     and hosts on directly connected networks. It is similar to	the behavior
     of	the address sort in BIND 4.9.x.	Responses sent to queries from the
     local host	will favor any of the directly connected networks. Responses
     sent to queries from any other hosts on a directly	connected network will
     prefer addresses on that same network. Responses to other queries will
     not be sorted.

     sortlist {
		 { localhost; localnets; };
		 { localnets; };
     };

   RRset Ordering
     When multiple records are returned	in an answer it	may be useful to con-
     figure the	order the records are placed into the response.	For example
     the records for a zone might be configured	to always be returned in the
     order they	are defined in the zone	file. Or perhaps a random shuffle of
     the records as they are returned is wanted. The rrset-order statement
     permits configuration of the ordering made	of the records in a multiple
     record response. The default, if no ordering is defined, is a cyclic
     ordering (round robin).

     An	order_spec is defined as follows:

       [ class class_name ][ type type_name ][ name "FQDN" ] order ordering

     If	no class is specified, the default is ANY.  If no Ictype is specified,
     the default is ANY.  If no	name is	specified, the default is "*".

     The legal values for ordering are:

     fixed   Records are returned in the order they are	defined	in the zone
	     file.

     random  Records are returned in some random order.

     cyclic  Records are returned in a round-robin order.

     For example:

	 rrset-order {
	     class IN type A name "rc.vix.com" order random;
	     order cyclic;
	 };

     will cause	any responses for type A records in class IN that have
     "rc.vix.com" as a suffix, to always be returned in	random order. All
     other records are returned	in cyclic order.

     If	multiple rrset-order statements	appear,	they are not combined--the
     last one applies.

     If	no rrset-order statement is specified, a default one of:

	 rrset-order { class ANY type ANY name "*" order cyclic	; };

     is	used.

   Glue	Ordering
     When running a root nameserver it is sometimes necessary to ensure	that
     other nameservers that are	priming	are successful.	 This requires that
     glue A records for	at least of the	nameservers are	returned in the	answer
     to	a priming query.  This can be achieved by setting preferred-glue A;
     which will	add A records before other types in the	additional section.

   EDNS
     Some firewalls fail to pass EDNS/UDP messages that	are larger than	cer-
     tain size,	512 or the UDP reassembly buffer.  To allow EDNS to work
     across such firewalls it is necessary to advertise	a EDNS buffer size
     that is small enough to not trigger failures.  edns-udp-size can be use
     to	adjust the advertised size.  Values less than 512 will be increased to
     512 and values greater than 4096 will be truncated	to 4096.

   Tuning
     lame-ttl
       Sets the	number of seconds to cache a lame server indication.  0	dis-
       ables caching.  Default is 600 (10 minutes).  Maximum value is 1800 (30
       minutes)

     max-ncache-ttl
       To reduce network traffic and increase performance the server store
       negative	answers.  max-ncache-ttl is used to set	a maximum retention
       time for	these answers in the server is seconds.	 The default
       max-ncache-ttl is 10800 seconds (3 hours).  max-ncache-ttl cannot
       exceed the maximum retention time for ordinary (positive) answers (7
       days) and will be silently truncated to 7 days if set to	a value	which
       is greater that 7 days.

     min-roots
       The minimum number of root servers that is required for a request for
       the root	servers	to be accepted.	 Default is 2.

THE ZONE STATEMENT
   Syntax
     zone domain_name [	( in | hs | hesiod | chaos ) ] {
       type master;
       file path_name;
       [ check-names ( warn | fail | ignore ); ]
       [ allow-update {	address_match_list }; ]
       [ allow-query { address_match_list }; ]
       [ allow-transfer	{ address_match_list };	]
       [ forward ( only	| first	); ]
       [ forwarders { [	ip_addr	; [ ip_addr ; ... ] ] }; ]
       [ dialup	yes_or_no; ]
       [ notify	( yes_or_no | explicit ); ]
       [ also-notify { ip_addr;	[ ip_addr; ... ] };
       [ pubkey	number number number string; ]
     };

     zone domain_name [	( in | hs | hesiod | chaos ) ] {
       type ( slave | stub );
       [ file path_name; ]
       masters [ port ip_port ]	{ ip_addr [ key	key_id ]; [ ...	] };
       [ check-names ( warn | fail | ignore ); ]
       [ allow-update {	address_match_list }; ]
       [ allow-query { address_match_list }; ]
       [ allow-transfer	{ address_match_list };	]
       [ forward ( only	| first	); ]
       [ forwarders { [	ip_addr	; [ ip_addr ; ... ] ] }; ]
       [ transfer-source ip_addr; ]
       [ max-transfer-time-in number; ]
       [ notify	yes_or_no; ]
       [ also-notify { ip_addr;	[ ip_addr; ... ] };
       [ pubkey	number number number string; ]
     };

     zone domain_name [	( in | hs | hesiod | chaos ) ] {
       type forward;
       [ forward ( only	| first	); ]
       [ forwarders { [	ip_addr	; [ ip_addr ; ... ] ] }; ]
       [ check-names ( warn | fail | ignore ); ]
     };

     zone "." [	( in | hs | hesiod | chaos ) ] {
       type hint;
       file path_name;
       [ check-names ( warn | fail | ignore ); ]
     };

   Definition and Usage
     The zone statement	is used	to define how information about	particular DNS
     zones is managed by the server.  There are	five different zone types.

     master
       The server has a	master copy of the data	for the	zone and will be able
       to provide authoritative	answers	for it.

     slave
       A slave zone is a replica of a master zone.  The	masters	list specifies
       one or more IP addresses	that the slave contacts	to update its copy of
       the zone.  If a port is specified then checks to	see if the zone	is
       current and zone	transfers will be done to the port given. If file is
       specified, then the replica will	be written to the named	file.  Use of
       the file	clause is highly recommended, since it often speeds server
       startup and eliminates a	needless waste of bandwidth.

     stub
       A stub zone is like a slave zone, except	that it	replicates only	the NS
       records of a master zone	instead	of the entire zone.

     forward
       A forward zone is used to direct	all queries in it to other servers, as
       described in THE	OPTIONS	STATEMENT section.  The	specification of
       options in such a zone will override any	global options declared	in the
       options statement.

       If either no forwarders clause is present in the	zone or	an empty list
       for forwarders is given,	then no	forwarding will	be done	for the	zone,
       cancelling the effects of any forwarders	in the options statement.
       Thus if you want	to use this type of zone to change only	the behavior
       of the global forward option, and not the servers used, then you	also
       need to respecify the global forwarders.

     hint
       The initial set of root nameservers is specified	using a	hint zone.
       When the	server starts up, it uses the root hints to find a root	name-
       server and get the most recent list of root nameservers.

     Note: previous releases of	BIND used the term primary for a master	zone,
     secondary for a slave zone, and cache for a hint zone.

   Classes
     The zone's	name may optionally be followed	by a class.  If	a class	is not
     specified,	class in (for "internet"), is assumed.	This is	correct	for
     the vast majority of cases.

     The hesiod	class is for an	information service from MIT's Project Athena.
     It	is used	to share information about various systems databases, such as
     users, groups, printers and so on.	 More information can be found at
     ftp://athena-dist.mit.edu/pub/ATHENA/usenix/athena_changes.PS.  The key-
     word hs is	a synonym for hesiod.

     Another MIT development was CHAOSnet, a LAN protocol created in the
     mid-1970s.	 It is still sometimes seen on LISP stations and other hard-
     ware in the AI community, and zone	data for it can	be specified with the
     chaos class.

   Options
     check-names
       See the subsection on Name Checking in THE OPTIONS STATEMENT.

     allow-query
       See the description of allow-query in the Access	Control	subsection of
       THE OPTIONS STATEMENT.

     allow-update
       Specifies which hosts are allowed to submit Dynamic DNS updates to the
       server.	The default is to deny updates from all	hosts.

     allow-transfer
       See the description of allow-transfer in	the Access Control subsection
       of THE OPTIONS STATEMENT.

     transfer-source
       transfer-source determines which	local address will be bound to the TCP
       connection used to fetch	this zone.  If not set,	it defaults to a sys-
       tem controlled value which will usually be the address of the interface
       ``closest to'' the remote end.  This address must appear	in the remote
       end's allow-transfer option for this zone if one	is specified.

     max-transfer-time-in
       See the description of max-transfer-time-in in the Zone Transfers sub-
       section of THE OPTIONS STATEMENT.

     dialup
       See the description of dialup in	the Boolean Options subsection of THE
       OPTIONS STATEMENT.

     notify
       See the description of notify in	the Boolean Options subsection of the
       THE OPTIONS STATEMENT.

     also-notify
       also-notify is only meaningful if notify	is active for this zone.  The
       set of machines that will receive a DNS NOTIFY message for this zone is
       made up of all the listed nameservers for the zone (other than the pri-
       mary master) plus any IP	addresses specified with also-notify.
       also-notify is not meaningful for stub zones.  The default is the empty
       list.

     forward
       forward is only meaningful if the zone has a forwarders list. The only
       value causes the	lookup to fail after trying the	forwarders and getting
       no answer, while	first would allow a normal lookup to be	tried.

     forwarders
       The forwarders option in	a zone is used to override the list of global
       forwarders.  If it is not specified in a	zone of	type forward, no for-
       warding is done for the zone; the global	options	are not	used.

     pubkey
       The DNSSEC flags, protocol, and algorithm are specified,	as well	as a
       base-64 encoded string representing the key.

THE ACL	STATEMENT
   Syntax
     acl name {
       address_match_list
     };

   Definition and Usage
     The acl statement creates a named address match list.  It gets its	name
     from a primary use	of address match lists:	 Access	Control	Lists (ACLs).

     Note that an address match	list's name must be defined with acl before it
     can be used elsewhere; no forward references are allowed.

     The following ACLs	are built-in:

     any
       Allows all hosts.

     none
       Denies all hosts.

     localhost
       Allows the IP addresses of all interfaces on the	system.

     localnets
       Allows any host on a network for	which the system has an	interface.

THE KEY	STATEMENT
   Syntax
     key key_id	{
       algorithm algorithm_id;
       secret secret_string;
     };

   Definition and Usage
     The key statement defines a key ID	which can be used in a server state-
     ment to associate a method	of authentication with a particular name
     server that is more rigorous than simple IP address matching.  A key ID
     must be created with the key statement before it can be used in a server
     definition	or an address match list.

     The algorithm_id is a string that specifies a security/authentication
     algorithm.	 secret_string is the secret to	be used	by the algorithm, and
     is	treated	as a base-64 encoded string.  It should	go without saying, but
     probably can't, that if you have secret_string 's in your named.conf,
     then it should not	be readable by anyone but the superuser.

THE TRUSTED-KEYS STATEMENT
   Syntax
     trusted-keys {
       [ domain_name flags protocol algorithm key; ]
     };

   Definition and Usage
     The trusted-keys statement	is for use with	DNSSEC-style security, origi-
     nally specified in	RFC 2065.  DNSSEC is meant to provide three distinct
     services: key distribution, data origin authentication, and transaction
     and request authentication.  A complete description of DNSSEC and its use
     is	beyond the scope of this document, and readers interested in more
     information should	start with RFC 2065 and	then continue with the Inter-
     net Drafts	available at http://www.ietf.org/ids.by.wg/dnssec.html.

     Each trusted key is associated with a domain name.	 Its attributes	are
     the non-negative integral flags, protocol,	and algorithm, as well as a
     base-64 encoded string representing the key.

     Any number	of trusted keys	can be specified.

THE SERVER STATEMENT
   Syntax
     server ip_addr {
       [ edns yes_or_no; ]
       [ bogus yes_or_no; ]
       [ support-ixfr yes_or_no; ]
       [ transfers number; ]
       [ transfer-format ( one-answer |	many-answers );	]
       [ keys {	key_id [ key_id	... ] }; ]
     };

   Definition and Usage
     The server	statement defines the characteristics to be associated with a
     remote name server.

     If	you discover that a server does	not support EDNS you can prevent named
     making EDNS queries to it by specifying edns no;.	The default value of
     edns is yes.

     If	you discover that a server is giving out bad data, marking it as bogus
     will prevent further queries to it.  The default value of bogus is	no.

     If	the server supports IXFR you can tell named to attempt to perform a
     IXFR style	zone transfer by specifing support-ixfr	yes.  The default
     value of support-ixfr is no.

     The server	supports two zone transfer methods.  The first,	one-answer,
     uses one DNS message per resource record transferred.  many-answers packs
     as	many resource records as possible into a message.  many-answers	is
     more efficient, but is only known to be understood	by BIND	8.1 and
     patched versions of BIND 4.9.5.  You can specify which method to use for
     a server with the transfer-format option.	If transfer-format is not
     specified,	the transfer-format specified by the options statement will be
     used.

     The transfers will	be used	in a future release of the server to limit the
     number of concurrent in-bound zone	transfers from the specified server.
     It	is checked for syntax but is otherwise ignored.

     The keys clause is	used to	identify a key_id defined by the key state-
     ment, to be used for transaction security when talking to the remote
     server.  The key statement	must come before the server statement that
     references	it.

     The keys statement	is intended for	future use by the server.  It is
     checked for syntax	but is otherwise ignored.

THE CONTROLS STATEMENT
   Syntax
     controls {
       [ inet ip_addr
	 port ip_port
	 allow { address_match_list; };	]
       [ unix path_name
	 perm number
	 owner number
	 group number; ]
     };

   Definition and Usage
     The controls statement declares control channels to be used by system
     administrators to affect the operation of the local name server.  These
     control channels are used by the ndc utility to send commands to and
     retrieve non-DNS results from a name server.

     A unix control channel is a FIFO in the file system, and access to	it is
     controlled	by normal file system permissions.  It is created by named
     with the specified	file mode bits (see chmod(1)), user and	group owner.
     Note that,	unlike chmod, the mode bits specified for perm will normally
     have a leading 0 so the number is interpreted as octal.  Also note	that
     the user and group	ownership specified as owner and group must be given
     as	numbers, not names.  It	is recommended that the	permissions be
     restricted	to administrative personnel only, or else any user on the sys-
     tem might be able to manage the local name	server.

     An	inet control channel is	a TCP/IP socket	accessible to the Internet,
     created at	the specified ip_port on the specified ip_addr.	 Modern	telnet
     clients are capable of speaking directly to these sockets,	and the	con-
     trol protocol is ARPAnet-style text.  It is recommended that 127.0.0.1 be
     the only ip_addr used, and	this only if you trust all non-privileged
     users on the local	host to	manage your name server.

THE INCLUDE STATEMENT
   Syntax
     include path_name;

   Definition and Usage
     The include statement inserts the specified file at the point that	the
     include statement is encountered.	It cannot be used within another
     statement,	though,	so a line such as
	   acl internal_hosts {	include	internal_hosts.acl; };
     is	not allowed.

     Use include to break the configuration up into easily-managed chunks.
     For example:

     include "/etc/security/keys.bind";
     include "/etc/acls.bind";

     could be used at the top of a BIND	configuration file in order to include
     any ACL or	key information.

     Be	careful	not to type ``#include'', like you would in a C	program,
     because ``#'' is used to start a comment.

EXAMPLES
     The simplest configuration	file that is still realistically useful	is one
     which simply defines a hint zone that has a full path to the root servers
     file.

     zone "." in {
	     type hint;
	     file "/var/named/root.cache";
     };

     Here's a more typical real-world example.

     /*
      *	A simple BIND 8	configuration
      */

     logging {
	     category lame-servers { null; };
	     category cname { null; };
     };

     options {
	     directory "/var/named";
     };

     controls {
	     inet * port 52 allow { any; };		     //	a bad idea
	     unix "/var/run/ndc" perm 0600 owner 0 group 0;  //	the default
     };

     zone "isc.org" in {
	     type master;
	     file "master/isc.org";
     };

     zone "vix.com" in {
	     type slave;
	     file "slave/vix.com";
	     masters { 10.0.0.53; };
     };

     zone "0.0.127.in-addr.arpa" in {
	     type master;
	     file "master/127.0.0";
     };

     zone "." in {
	     type hint;
	     file "root.cache";
     };

FILES
     /etc/namedb/named.conf
       The BIND	8 named	configuration file.

SEE ALSO
     named(8), ndc(8)

4th Berkeley Distribution	January	7, 1999	     4th Berkeley Distribution

NAME | OVERVIEW | DOCUMENTATION DEFINITIONS | ADDRESS MATCH LISTS | THE LOGGING STATEMENT | THE OPTIONS STATEMENT | THE ZONE STATEMENT | THE ACL STATEMENT | THE KEY STATEMENT | THE TRUSTED-KEYS STATEMENT | THE SERVER STATEMENT | THE CONTROLS STATEMENT | THE INCLUDE STATEMENT | EXAMPLES | FILES | SEE ALSO

Want to link to this manual page? Use this URL:
<http://www.freebsd.org/cgi/man.cgi?query=named.conf&sektion=5&manpath=FreeBSD+5.2.1-RELEASE>

home | help