19.2.2. Other Statement Types
The following is a list of lesser used statement types available within
named.conf:
-
controls - Configures various security requirements necessary to use the
rndccommand to administer thenamedservice.Refer to Section 19.4.1, “Configuring/etc/named.conf” to learn more about how thecontrolsstatement is structured and what options are available. -
key "<key-name>" - Defines a particular key by name. Keys are used to authenticate various actions, such as secure updates or the use of the
rndccommand. Two options are used withkey:algorithm <algorithm-name>— The type of algorithm used, such asdsaorhmac-md5.secret "<key-value>"— The encrypted key.
Refer to Section 19.4.2, “Configuring/etc/rndc.conf” for instructions on how to write akeystatement. -
logging - Allows for the use of multiple types of logs, called channels. By using the
channeloption within theloggingstatement, a customized type of log can be constructed — with its own file name (file), size limit (size), versioning (version), and level of importance (severity). Once a customized channel is defined, acategoryoption is used to categorize the channel and begin logging whennamedis restarted.By default,namedlogs standard messages to thesyslogdaemon, which places them in/var/log/messages. This occurs because several standard channels are built into BIND with various severity levels, such asdefault_syslog(which handles informational logging messages) anddefault_debug(which specifically handles debugging messages). A default category, calleddefault, uses the built-in channels to do normal logging without any special configuration.Customizing the logging process can be a very detailed process and is beyond the scope of this chapter. For information on creating custom BIND logs, refer to the BIND 9 Administrator Reference Manual referenced in Section 19.7.1, “Installed Documentation”. -
server - Specifies options that affect how
namedshould respond to remote nameservers, especially with regard to notifications and zone transfers.Thetransfer-formatoption controls whether one resource record is sent with each message (one-answer) or multiple resource records are sent with each message (many-answers). Whilemany-answersis more efficient, only newer BIND nameservers understand it. -
trusted-keys - Contains assorted public keys used for secure DNS (DNSSEC). Refer to Section 19.5.3, “Security” for more information concerning BIND security.
-
view "<view-name>" - Creates special views depending upon which network the host querying the nameserver is on. This allows some hosts to receive one answer regarding a zone while other hosts receive totally different information. Alternatively, certain zones may only be made available to particular trusted hosts while non-trusted hosts can only make queries for other zones.Multiple views may be used, but their names must be unique. The
match-clientsoption specifies the IP addresses that apply to a particular view. Anyoptionsstatement may also be used within a view, overriding the global options already configured fornamed. Mostviewstatements contain multiplezonestatements that apply to thematch-clientslist. The order in whichviewstatements are listed is important, as the firstviewstatement that matches a particular client's IP address is used.Refer to Section 19.5.2, “Multiple Views” for more information about theviewstatement.