Options are:
Any additional argument is taken as the name of the boot file. The boot file contains information about where the name server is to get its initial data. If multiple boot files are specified, only the last is used. Lines in the boot file cannot be continued on subsequent lines. The following is a small example:
; ; boot file for name server ; directory /usr/local/domain ; type domain source host/file backup file cache . root.cache primary Berkeley.EDU berkeley.edu.zone primary 32.128.IN-ADDR.ARPA ucbhosts.rev secondary CC.Berkeley.EDU 128.32.137.8 128.32.137.3 cc.zone.bak secondary 6.32.128.IN-ADDR.ARPA 128.32.137.8 128.32.137.3 cc.rev.bak primary 0.0.127.IN-ADDR.ARPA localhost.rev forwarders 10.0.0.78 10.2.0.78 ; slaveThe ``directory'' line causes the server to change its working directory to the directory specified. This can be important for the correct processing of $INCLUDE files in primary zone files.
The ``cache'' line specifies that data in ``root.cache'' is to be placed in the backup cache. Its main use is to specify data such as locations of root domain servers. This cache is not used during normal operation, but is used as ``hints'' to find the current root servers. The file ``root.cache'' is in the same format as ``berkeley.edu.zone''. There can be more than one ``cache'' file specified. The cache files are processed in such a way as to preserve the time-to-live's of data dumped out. Data for the root nameservers is kept artificially valid if necessary.
The first ``primary'' line states that the file ``berkeley.edu.zone'' contains authoritative data for the ``Berkeley.EDU'' zone. The file ``berkeley.edu.zone'' contains data in the master file format described in RFC883. All domain names are relative to the origin, in this case, ``Berkeley.EDU'' (see below for a more detailed description). The second ``primary'' line states that the file ``ucbhosts.rev'' contains authoritative data for the domain ``32.128.IN-ADDR.ARPA,'' which is used to translate addresses in network 128.32 to hostnames. Each master file should begin with an SOA record for the zone (see below).
The first ``secondary'' line specifies that all authoritative data under ``CC.Berkeley.EDU'' is to be transferred from the name server at 128.32.137.8. If the transfer fails it will try 128.32.137.3 and continue trying the addresses, up to 10, listed on this line. The secondary copy is also authoritative for the specified domain. The first non-dotted-quad address on this line will be taken as a filename in which to backup the transfered zone. The name server will load the zone from this backup file if it exists when it boots, providing a complete copy even if the master servers are unreachable. Whenever a new copy of the domain is received by automatic zone transfer from one of the master servers, this file will be updated. The second ``secondary'' line states that the address-to-hostname mapping for the subnet 128.32.136 should be obtained from the same list of master servers as the previous zone.
The ``forwarders'' line specifies the addresses of sitewide servers that will accept recursive queries from other servers. If the boot file specifies one or more forwarders, then the server will send all queries for data not in the cache to the forwarders first. Each forwarder will be asked in turn until an answer is returned or the list is exhausted. If no answer is forthcoming from a forwarder, the server will continue as it would have without the forwarders line unless it is in ``slave'' mode. The forwarding facility is useful to cause a large sitewide cache to be generated on a master, and to reduce traffic over links to outside servers. It can also be used to allow servers to run that do not have access directly to the Internet, but wish to act as though they do.
The ``slave'' line (shown commented out) is used to put the server in slave mode. In this mode, the server will only make queries to forwarders. This option is normally used on machine that wish to run a server but for physical or administrative reasons cannot be given access to the Internet, but have access to a host that does have access.
The ``sortlist'' line can be used to indicate networks that are to be preferred over other, unlisted networks. Queries for host addresses from hosts on the same network as the server will receive responses with local network addresses listed first, then addresses on the sort list, then other addresses. This line is only acted on at initial startup. When reloading the nameserver with a SIGHUP, this line will be ignored.
The master file consists of control information and a list of resource records for objects in the zone of the forms:
$INCLUDE <filename> <opt_domain> $ORIGIN <domain> <domain> <opt_ttl> <opt_class> <type> <resource_record_data>
Resource records normally end at the end of a line, but may be continued across lines between opening and closing parentheses. Comments are introduced by semicolons and continue to the end of the line.
Each master zone file should begin with an SOA record for the zone. An example SOA record is as follows:
@ IN SOA ucbvax.Berkeley.EDU. rwh.ucbvax.Berkeley.EDU. (
2.89 ; serial
10800 ; refresh
3600 ; retry
3600000 ; expire
86400 ) ; minimum
The SOA lists a serial number, which should be changed each time the master file is changed. Secondary servers check the serial number at intervals specified by the refresh time in seconds; if the serial number changes, a zone transfer will be done to load the new data. If a master server cannot be contacted when a refresh is due, the retry time specifies the interval at which refreshes should be attempted until successful. If a master server cannot be contacted within the interval given by the expire time, all data from the zone is discarded by secondary servers. The minimum value is the time-to-live used by records in the file with no explicit time-to-live value.
The following signals have the specified effect when sent to the server process using the kill(1) command.
/etc/named.boot name server configuration boot file /etc/named.pid the process id /usr/tmp/named.run debug output /usr/tmp/named_dump.db dump of the name server database /usr/tmp/named.stats nameserver statistics data