1NAMED(8) BIND9 NAMED(8)
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6 named - Internet domain name server
7
9 named [-4] [-6] [-c config-file] [-d debug-level] [-E engine-name] [-f]
10 [-g] [-m flag] [-n #cpus] [-p port] [-s] [-S #max-socks]
11 [-t directory] [-U #listeners] [-u user] [-v] [-V]
12 [-x cache-file]
13
15 named is a Domain Name System (DNS) server, part of the BIND 9
16 distribution from ISC. For more information on the DNS, see RFCs 1033,
17 1034, and 1035.
18 When invoked without arguments, named will read the default
20 configuration file /etc/named.conf, read any initial data, and listen
21 for queries.
22
24 -4
25 Use IPv4 only even if the host machine is capable of IPv6. -4 and
26 -6 are mutually exclusive.
27 -6
29 Use IPv6 only even if the host machine is capable of IPv4. -4 and
30 -6 are mutually exclusive.
31 -c config-file
33 Use config-file as the configuration file instead of the default,
34 /etc/named.conf. To ensure that reloading the configuration file
35 continues to work after the server has changed its working
36 directory due to to a possible directory option in the
37 configuration file, config-file should be an absolute pathname.
38 -d debug-level
40 Set the daemon's debug level to debug-level. Debugging traces from
41 named become more verbose as the debug level increases.
42 -E engine-name
44 Use a crypto hardware (OpenSSL engine) for the crypto operations it
45 supports, for instance re-signing with private keys from a secure
46 key store. When compiled with PKCS#11 support engine-name defaults
47 to pkcs11, the empty name resets it to no engine.
48 -f
50 Run the server in the foreground (i.e. do not daemonize).
51 -g
53 Run the server in the foreground and force all logging to stderr.
54 -m flag
56 Turn on memory usage debugging flags. Possible flags are usage,
57 trace, record, size, and mctx. These correspond to the
58 ISC_MEM_DEBUGXXXX flags described in <isc/mem.h>.
59 -n #cpus
61 Create #cpus worker threads to take advantage of multiple CPUs. If
62 not specified, named will try to determine the number of CPUs
63 present and create one thread per CPU. If it is unable to determine
64 the number of CPUs, a single worker thread will be created.
65 -p port
67 Listen for queries on port port. If not specified, the default is
68 port 53.
69 -s
71 Write memory usage statistics to stdout on exit.
72 Note: This option is mainly of interest to BIND 9 developers
73 and may be removed or changed in a future release.
74 -S #max-socks
76 Allow named to use up to #max-socks sockets.
77 Warning: This option should be unnecessary for the vast
78 majority of users. The use of this option could even be
79 harmful because the specified value may exceed the
80 limitation of the underlying system API. It is therefore set
81 only when the default configuration causes exhaustion of
82 file descriptors and the operational environment is known to
83 support the specified number of sockets. Note also that the
84 actual maximum number is normally a little fewer than the
85 specified value because named reserves some file descriptors
86 for its internal use.
87 -t directory
89 Chroot to directory after processing the command line arguments,
90 but before reading the configuration file.
91 Warning: This option should be used in conjunction with the
92 -u option, as chrooting a process running as root doesn't
93 enhance security on most systems; the way chroot(2) is
94 defined allows a process with root privileges to escape a
95 chroot jail.
96 -U #listeners
98 Use #listeners worker threads to listen for incoming UDP packets on
99 each address. If not specified, named will use the number of
100 detected CPUs. If -n has been set to a higher value than the number
101 of CPUs, then -U may be increased as high as that value, but no
102 higher.
103 -u user
105 Setuid to user after completing privileged operations, such as
106 creating sockets that listen on privileged ports.
107 Note: On Linux, named uses the kernel's capability mechanism
108 to drop all root privileges except the ability to bind(2) to
109 a privileged port and set process resource limits.
110 Unfortunately, this means that the -u option only works when
111 named is run on kernel 2.2.18 or later, or kernel
112 2.3.99-pre3 or later, since previous kernels did not allow
113 privileges to be retained after setuid(2).
114 -v
116 Report the version number and exit.
117 -V
119 Report the version number and build options, and exit.
120 -x cache-file
122 Load data from cache-file into the cache of the default view.
123 Warning: This option must not be used. It is only of
124 interest to BIND 9 developers and may be removed or changed
125 in a future release.
126
128 In routine operation, signals should not be used to control the
129 nameserver; rndc should be used instead.
130 SIGHUP
132 Force a reload of the server.
133 SIGINT, SIGTERM
135 Shut down the server.
136 The result of sending any other signals to the server is undefined.
138
140 The named configuration file is too complex to describe in detail here.
141 A complete description is provided in the BIND 9 Administrator
142 Reference Manual.
143 named inherits the umask (file creation mode mask) from the parent
145 process. If files created by named, such as journal files, need to have
146 custom permissions, the umask should be set explicitly in the script
147 used to start the named process.
148
150 /etc/named.conf
151 The default configuration file.
152 /var/run/named/named.pid
154 The default process-id file.
155
157 Red Hat SELinux BIND Security Profile:
158 By default, Red Hat ships BIND with the most secure SELinux policy that
160 will not prevent normal BIND operation and will prevent exploitation of
161 all known BIND security vulnerabilities . See the selinux(8) man page
162 for information about SElinux.
163 It is not necessary to run named in a chroot environment if the Red Hat
165 SELinux policy for named is enabled. When enabled, this policy is far
166 more secure than a chroot environment. Users are recommended to enable
167 SELinux and remove the bind-chroot package.
168 With this extra security comes some restrictions:
170 By default, the SELinux policy does not allow named to write any master
172 zone database files. Only the root user may create files in the
173 $ROOTDIR/var/named zone database file directory (the options {
174 "directory" } option), where $ROOTDIR is set in /etc/sysconfig/named.
175 The "named" group must be granted read privelege to these files in
177 order for named to be enabled to read them.
178 Any file created in the zone database file directory is automatically
180 assigned the SELinux file context named_zone_t .
181 By default, SELinux prevents any role from modifying named_zone_t
183 files; this means that files in the zone database directory cannot be
184 modified by dynamic DNS (DDNS) updates or zone transfers.
185 The Red Hat BIND distribution and SELinux policy creates three
187 directories where named is allowed to create and modify files:
188 /var/named/slaves, /var/named/dynamic /var/named/data. By placing files
189 you want named to modify, such as slave or DDNS updateable zone files
190 and database / statistics dump files in these directories, named will
191 work normally and no further operator action is required. Files in
192 these directories are automatically assigned the 'named_cache_t' file
193 context, which SELinux allows named to write.
194 Red Hat BIND SDB support:
196 Red Hat ships named with compiled in Simplified Database Backend
198 modules that ISC provides in the "contrib/sdb" directory. Install bind-
199 sdb package if you want use them
200 The SDB modules for LDAP, PostGreSQL, DirDB and SQLite are compiled
202 into named-sdb.
203 See the documentation for the various SDB modules in
205 /usr/share/doc/bind-sdb-*/ .
206
208 RFC 1033, RFC 1034, RFC 1035, named-checkconf(8), named-checkzone(8),
209 rndc(8), lwresd(8), named.conf(5), BIND 9 Administrator Reference
210 Manual.
211
213 Internet Systems Consortium
214
216 Copyright © 2004-2009, 2011, 2013 Internet Systems Consortium, Inc.
217 ("ISC")
218 Copyright © 2000, 2001, 2003 Internet Software Consortium.
219BIND9 May 21, 2009 NAMED(8)