NAMED(8) | BIND9 | NAMED(8) |
NAME¶
named - Internet domain name server
SYNOPSIS¶
named [[-4] | [-6]] [-c config-file] [-d debug-level] [-D string] [-E engine-name] [-f] [-g] [-L logfile] [-M option] [-m flag] [-n #cpus] [-p port] [-s] [-S #max-socks] [-t directory] [-U #listeners] [-u user] [-v] [-V] [-X lock-file] [-x cache-file]
DESCRIPTION¶
named is a Domain Name System (DNS) server, part of the BIND 9 distribution from ISC. For more information on the DNS, see RFCs 1033, 1034, and 1035.
When invoked without arguments, named will read the default configuration file /etc/named.conf, read any initial data, and listen for queries.
OPTIONS¶
-4
-6
-c config-file
-d debug-level
-D string
-E engine-name
When BIND is built with OpenSSL PKCS#11 support, this defaults to the string "pkcs11", which identifies an OpenSSL engine that can drive a cryptographic accelerator or hardware service module. When BIND is built with native PKCS#11 cryptography (--enable-native-pkcs11), it defaults to the path of the PKCS#11 provider library specified via "--with-pkcs11".
-f
-g
-L logfile
-M option
-m flag
-n #cpus
-p port
-s
Note
This option is mainly of interest to BIND 9 developers and may be removed or changed in a future release.
-S #max-socks
Warning
This option should be unnecessary for the vast majority of users. The use of this option could even be harmful because the specified value may exceed the limitation of the underlying system API. It is therefore set only when the default configuration causes exhaustion of file descriptors and the operational environment is known to support the specified number of sockets. Note also that the actual maximum number is normally a little fewer than the specified value because named reserves some file descriptors for its internal use.
-t directory
Warning
This option should be used in conjunction with the -u option, as chrooting a process running as root doesn't enhance security on most systems; the way chroot(2) is defined allows a process with root privileges to escape a chroot jail.
-U #listeners
-u user
Note
On Linux, named uses the kernel's capability mechanism to drop all root privileges except the ability to bind(2) to a privileged port and set process resource limits. Unfortunately, this means that the -u option only works when named is run on kernel 2.2.18 or later, or kernel 2.3.99-pre3 or later, since previous kernels did not allow privileges to be retained after setuid(2).
-v
-V
-X lock-file
-x cache-file
Warning
This option must not be used. It is only of interest to BIND 9 developers and may be removed or changed in a future release.
SIGNALS¶
In routine operation, signals should not be used to control the nameserver; rndc should be used instead.
SIGHUP
SIGINT, SIGTERM
The result of sending any other signals to the server is undefined.
CONFIGURATION¶
The named configuration file is too complex to describe in detail here. A complete description is provided in the BIND 9 Administrator Reference Manual.
named inherits the umask (file creation mode mask) from the parent process. If files created by named, such as journal files, need to have custom permissions, the umask should be set explicitly in the script used to start the named process.
FILES¶
/etc/named.conf
/var/run/named/named.pid
NOTES¶
By default, Red Hat ships BIND with the most secure SELinux policy that will not prevent normal BIND operation and will prevent exploitation of all known BIND security vulnerabilities . See the selinux(8) man page for information about SElinux.
It is not necessary to run named in a chroot environment if the Red Hat SELinux policy for named is enabled. When enabled, this policy is far more secure than a chroot environment. Users are recommended to enable SELinux and remove the bind-chroot package.
With this extra security comes some restrictions:
By default, the SELinux policy does not allow named to write any master zone database files. Only the root user may create files in the $ROOTDIR/var/named zone database file directory (the options { "directory" } option), where $ROOTDIR is set in /etc/sysconfig/named.
The "named" group must be granted read privelege to these files in order for named to be enabled to read them.
Any file created in the zone database file directory is automatically assigned the SELinux file context named_zone_t .
By default, SELinux prevents any role from modifying named_zone_t files; this means that files in the zone database directory cannot be modified by dynamic DNS (DDNS) updates or zone transfers.
The Red Hat BIND distribution and SELinux policy creates three directories where named is allowed to create and modify files: /var/named/slaves, /var/named/dynamic /var/named/data. By placing files you want named to modify, such as slave or DDNS updateable zone files and database / statistics dump files in these directories, named will work normally and no further operator action is required. Files in these directories are automatically assigned the 'named_cache_t' file context, which SELinux allows named to write.
Red Hat BIND SDB support:
Red Hat ships named with compiled in Simplified Database Backend modules that ISC provides in the "contrib/sdb" directory. Install bind-sdb package if you want use them
The SDB modules for LDAP, PostGreSQL, DirDB and SQLite are compiled into named-sdb.
See the documentation for the various SDB modules in
/usr/share/doc/bind-sdb-*/ .
SEE ALSO¶
RFC 1033, RFC 1034, RFC 1035, named-checkconf(8), named-checkzone(8), rndc(8), lwresd(8), named.conf(5), BIND 9 Administrator Reference Manual.
AUTHOR¶
Internet Systems Consortium, Inc.
COPYRIGHT¶
Copyright © 2000, 2001, 2003-2009, 2011, 2013-2018 Internet Systems Consortium, Inc. ("ISC")
2014-02-19 | ISC |