1<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" 2 "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd" 3 [<!ENTITY mdash "—">]> 4<!-- 5 - Copyright (C) 2004-2009, 2011, 2013, 2014 Internet Systems Consortium, Inc. ("ISC") 6 - Copyright (C) 2000, 2001, 2003 Internet Software Consortium. 7 - 8 - Permission to use, copy, modify, and/or distribute this software for any 9 - purpose with or without fee is hereby granted, provided that the above 10 - copyright notice and this permission notice appear in all copies. 11 - 12 - THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH 13 - REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY 14 - AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, 15 - INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM 16 - LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE 17 - OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR 18 - PERFORMANCE OF THIS SOFTWARE. 19--> 20 21<refentry id="man.named"> 22 <refentryinfo> 23 <date>February 19, 2014</date> 24 </refentryinfo> 25 26 <refmeta> 27 <refentrytitle><application>named</application></refentrytitle> 28 <manvolnum>8</manvolnum> 29 <refmiscinfo>BIND9</refmiscinfo> 30 </refmeta> 31 32 <refnamediv> 33 <refname><application>named</application></refname> 34 <refpurpose>Internet domain name server</refpurpose> 35 </refnamediv> 36 37 <docinfo> 38 <copyright> 39 <year>2004</year> 40 <year>2005</year> 41 <year>2006</year> 42 <year>2007</year> 43 <year>2008</year> 44 <year>2009</year> 45 <year>2011</year> 46 <year>2013</year> 47 <year>2014</year> 48 <holder>Internet Systems Consortium, Inc. ("ISC")</holder> 49 </copyright> 50 <copyright> 51 <year>2000</year> 52 <year>2001</year> 53 <year>2003</year> 54 <holder>Internet Software Consortium.</holder> 55 </copyright> 56 </docinfo> 57 58 <refsynopsisdiv> 59 <cmdsynopsis> 60 <command>named</command> 61 <arg><option>-4</option></arg> 62 <arg><option>-6</option></arg> 63 <arg><option>-c <replaceable class="parameter">config-file</replaceable></option></arg> 64 <arg><option>-d <replaceable class="parameter">debug-level</replaceable></option></arg> 65 <arg><option>-D <replaceable class="parameter">string</replaceable></option></arg> 66 <arg><option>-E <replaceable class="parameter">engine-name</replaceable></option></arg> 67 <arg><option>-f</option></arg> 68 <arg><option>-g</option></arg> 69 <arg><option>-m <replaceable class="parameter">flag</replaceable></option></arg> 70 <arg><option>-n <replaceable class="parameter">#cpus</replaceable></option></arg> 71 <arg><option>-p <replaceable class="parameter">port</replaceable></option></arg> 72 <arg><option>-s</option></arg> 73 <arg><option>-S <replaceable class="parameter">#max-socks</replaceable></option></arg> 74 <arg><option>-t <replaceable class="parameter">directory</replaceable></option></arg> 75 <arg><option>-U <replaceable class="parameter">#listeners</replaceable></option></arg> 76 <arg><option>-u <replaceable class="parameter">user</replaceable></option></arg> 77 <arg><option>-v</option></arg> 78 <arg><option>-V</option></arg> 79 <arg><option>-x <replaceable class="parameter">cache-file</replaceable></option></arg> 80 </cmdsynopsis> 81 </refsynopsisdiv> 82 83 <refsect1> 84 <title>DESCRIPTION</title> 85 <para><command>named</command> 86 is a Domain Name System (DNS) server, 87 part of the BIND 9 distribution from ISC. For more 88 information on the DNS, see RFCs 1033, 1034, and 1035. 89 </para> 90 <para> 91 When invoked without arguments, <command>named</command> 92 will 93 read the default configuration file 94 <filename>/etc/named.conf</filename>, read any initial 95 data, and listen for queries. 96 </para> 97 </refsect1> 98 99 <refsect1> 100 <title>OPTIONS</title> 101 102 <variablelist> 103 <varlistentry> 104 <term>-4</term> 105 <listitem> 106 <para> 107 Use IPv4 only even if the host machine is capable of IPv6. 108 <option>-4</option> and <option>-6</option> are mutually 109 exclusive. 110 </para> 111 </listitem> 112 </varlistentry> 113 114 <varlistentry> 115 <term>-6</term> 116 <listitem> 117 <para> 118 Use IPv6 only even if the host machine is capable of IPv4. 119 <option>-4</option> and <option>-6</option> are mutually 120 exclusive. 121 </para> 122 </listitem> 123 </varlistentry> 124 125 <varlistentry> 126 <term>-c <replaceable class="parameter">config-file</replaceable></term> 127 <listitem> 128 <para> 129 Use <replaceable class="parameter">config-file</replaceable> as the 130 configuration file instead of the default, 131 <filename>/etc/named.conf</filename>. To 132 ensure that reloading the configuration file continues 133 to work after the server has changed its working 134 directory due to to a possible 135 <option>directory</option> option in the configuration 136 file, <replaceable class="parameter">config-file</replaceable> should be 137 an absolute pathname. 138 </para> 139 </listitem> 140 </varlistentry> 141 142 <varlistentry> 143 <term>-d <replaceable class="parameter">debug-level</replaceable></term> 144 <listitem> 145 <para> 146 Set the daemon's debug level to <replaceable class="parameter">debug-level</replaceable>. 147 Debugging traces from <command>named</command> become 148 more verbose as the debug level increases. 149 </para> 150 </listitem> 151 </varlistentry> 152 153 <varlistentry> 154 <term>-D <replaceable class="parameter">string</replaceable></term> 155 <listitem> 156 <para> 157 Specifies a string that is used to identify a instance of 158 <command>named</command> in a process listing. The contents 159 of <replaceable class="parameter">string</replaceable> are 160 not examined. 161 </para> 162 </listitem> 163 </varlistentry> 164 165 <varlistentry> 166 <term>-E <replaceable class="parameter">engine-name</replaceable></term> 167 <listitem> 168 <para> 169 When applicable, specifies the hardware to use for 170 cryptographic operations, such as a secure key store used 171 for signing. 172 </para> 173 <para> 174 When BIND is built with OpenSSL PKCS#11 support, this defaults 175 to the string "pkcs11", which identifies an OpenSSL engine 176 that can drive a cryptographic accelerator or hardware service 177 module. When BIND is built with native PKCS#11 cryptography 178 (--enable-native-pkcs11), it defaults to the path of the PKCS#11 179 provider library specified via "--with-pkcs11". 180 </para> 181 </listitem> 182 </varlistentry> 183 184 <varlistentry> 185 <term>-f</term> 186 <listitem> 187 <para> 188 Run the server in the foreground (i.e. do not daemonize). 189 </para> 190 </listitem> 191 </varlistentry> 192 193 <varlistentry> 194 <term>-g</term> 195 <listitem> 196 <para> 197 Run the server in the foreground and force all logging 198 to <filename>stderr</filename>. 199 </para> 200 </listitem> 201 </varlistentry> 202 203 <varlistentry> 204 <term>-m <replaceable class="parameter">flag</replaceable></term> 205 <listitem> 206 <para> 207 Turn on memory usage debugging flags. Possible flags are 208 <replaceable class="parameter">usage</replaceable>, 209 <replaceable class="parameter">trace</replaceable>, 210 <replaceable class="parameter">record</replaceable>, 211 <replaceable class="parameter">size</replaceable>, and 212 <replaceable class="parameter">mctx</replaceable>. 213 These correspond to the ISC_MEM_DEBUGXXXX flags described in 214 <filename><isc/mem.h></filename>. 215 </para> 216 </listitem> 217 </varlistentry> 218 219 <varlistentry> 220 <term>-n <replaceable class="parameter">#cpus</replaceable></term> 221 <listitem> 222 <para> 223 Create <replaceable class="parameter">#cpus</replaceable> worker threads 224 to take advantage of multiple CPUs. If not specified, 225 <command>named</command> will try to determine the 226 number of CPUs present and create one thread per CPU. 227 If it is unable to determine the number of CPUs, a 228 single worker thread will be created. 229 </para> 230 </listitem> 231 </varlistentry> 232 233 <varlistentry> 234 <term>-p <replaceable class="parameter">port</replaceable></term> 235 <listitem> 236 <para> 237 Listen for queries on port <replaceable class="parameter">port</replaceable>. If not 238 specified, the default is port 53. 239 </para> 240 </listitem> 241 </varlistentry> 242 243 <varlistentry> 244 <term>-s</term> 245 <listitem> 246 <para> 247 Write memory usage statistics to <filename>stdout</filename> on exit. 248 </para> 249 <note> 250 <para> 251 This option is mainly of interest to BIND 9 developers 252 and may be removed or changed in a future release. 253 </para> 254 </note> 255 </listitem> 256 </varlistentry> 257 258 <varlistentry> 259 <term>-S <replaceable class="parameter">#max-socks</replaceable></term> 260 <listitem> 261 <para> 262 Allow <command>named</command> to use up to 263 <replaceable class="parameter">#max-socks</replaceable> sockets. 264 The default value is 4096 on systems built with default 265 configuration options, and 21000 on systems built with 266 "configure --with-tuning=large". 267 </para> 268 <warning> 269 <para> 270 This option should be unnecessary for the vast majority 271 of users. 272 The use of this option could even be harmful because the 273 specified value may exceed the limitation of the 274 underlying system API. 275 It is therefore set only when the default configuration 276 causes exhaustion of file descriptors and the 277 operational environment is known to support the 278 specified number of sockets. 279 Note also that the actual maximum number is normally a little 280 fewer than the specified value because 281 <command>named</command> reserves some file descriptors 282 for its internal use. 283 </para> 284 </warning> 285 </listitem> 286 </varlistentry> 287 288 <varlistentry> 289 <term>-t <replaceable class="parameter">directory</replaceable></term> 290 <listitem> 291 <para>Chroot 292 to <replaceable class="parameter">directory</replaceable> after 293 processing the command line arguments, but before 294 reading the configuration file. 295 </para> 296 <warning> 297 <para> 298 This option should be used in conjunction with the 299 <option>-u</option> option, as chrooting a process 300 running as root doesn't enhance security on most 301 systems; the way <function>chroot(2)</function> is 302 defined allows a process with root privileges to 303 escape a chroot jail. 304 </para> 305 </warning> 306 </listitem> 307 </varlistentry> 308 309 <varlistentry> 310 <term>-U <replaceable class="parameter">#listeners</replaceable></term> 311 <listitem> 312 <para> 313 Use <replaceable class="parameter">#listeners</replaceable> 314 worker threads to listen for incoming UDP packets on each 315 address. If not specified, <command>named</command> will 316 calculate a default value based on the number of detected 317 CPUs: 1 for 1 CPU, 2 for 2-4 CPUs, and the number of 318 detected CPUs divided by 2 for values higher than 4. 319 If <option>-n</option> has been set to a higher value than 320 the number of detected CPUs, then <option>-U</option> may 321 be increased as high as that value, but no higher. 322 </para> 323 </listitem> 324 </varlistentry> 325 326 <varlistentry> 327 <term>-u <replaceable class="parameter">user</replaceable></term> 328 <listitem> 329 <para>Setuid 330 to <replaceable class="parameter">user</replaceable> after completing 331 privileged operations, such as creating sockets that 332 listen on privileged ports. 333 </para> 334 <note> 335 <para> 336 On Linux, <command>named</command> uses the kernel's 337 capability mechanism to drop all root privileges 338 except the ability to <function>bind(2)</function> to 339 a 340 privileged port and set process resource limits. 341 Unfortunately, this means that the <option>-u</option> 342 option only works when <command>named</command> is 343 run 344 on kernel 2.2.18 or later, or kernel 2.3.99-pre3 or 345 later, since previous kernels did not allow privileges 346 to be retained after <function>setuid(2)</function>. 347 </para> 348 </note> 349 </listitem> 350 </varlistentry> 351 352 <varlistentry> 353 <term>-v</term> 354 <listitem> 355 <para> 356 Report the version number and exit. 357 </para> 358 </listitem> 359 </varlistentry> 360 361 <varlistentry> 362 <term>-V</term> 363 <listitem> 364 <para> 365 Report the version number and build options, and exit. 366 </para> 367 </listitem> 368 </varlistentry> 369 370 <varlistentry> 371 <term>-x <replaceable class="parameter">cache-file</replaceable></term> 372 <listitem> 373 <para> 374 Load data from <replaceable class="parameter">cache-file</replaceable> into the 375 cache of the default view. 376 </para> 377 <warning> 378 <para> 379 This option must not be used. It is only of interest 380 to BIND 9 developers and may be removed or changed in a 381 future release. 382 </para> 383 </warning> 384 </listitem> 385 </varlistentry> 386 387 </variablelist> 388 389 </refsect1> 390 391 <refsect1> 392 <title>SIGNALS</title> 393 <para> 394 In routine operation, signals should not be used to control 395 the nameserver; <command>rndc</command> should be used 396 instead. 397 </para> 398 399 <variablelist> 400 401 <varlistentry> 402 <term>SIGHUP</term> 403 <listitem> 404 <para> 405 Force a reload of the server. 406 </para> 407 </listitem> 408 </varlistentry> 409 410 <varlistentry> 411 <term>SIGINT, SIGTERM</term> 412 <listitem> 413 <para> 414 Shut down the server. 415 </para> 416 </listitem> 417 </varlistentry> 418 419 </variablelist> 420 421 <para> 422 The result of sending any other signals to the server is undefined. 423 </para> 424 425 </refsect1> 426 427 <refsect1> 428 <title>CONFIGURATION</title> 429 <para> 430 The <command>named</command> configuration file is too complex 431 to describe in detail here. A complete description is provided 432 in the 433 <citetitle>BIND 9 Administrator Reference Manual</citetitle>. 434 </para> 435 436 <para> 437 <command>named</command> inherits the <function>umask</function> 438 (file creation mode mask) from the parent process. If files 439 created by <command>named</command>, such as journal files, 440 need to have custom permissions, the <function>umask</function> 441 should be set explicitly in the script used to start the 442 <command>named</command> process. 443 </para> 444 445 </refsect1> 446 447 <refsect1> 448 <title>FILES</title> 449 450 <variablelist> 451 452 <varlistentry> 453 <term><filename>/etc/named.conf</filename></term> 454 <listitem> 455 <para> 456 The default configuration file. 457 </para> 458 </listitem> 459 </varlistentry> 460 461 <varlistentry> 462 <term><filename>/var/run/named/named.pid</filename></term> 463 <listitem> 464 <para> 465 The default process-id file. 466 </para> 467 </listitem> 468 </varlistentry> 469 470 </variablelist> 471 472 </refsect1> 473 474 <refsect1> 475 <title>SEE ALSO</title> 476 <para><citetitle>RFC 1033</citetitle>, 477 <citetitle>RFC 1034</citetitle>, 478 <citetitle>RFC 1035</citetitle>, 479 <citerefentry> 480 <refentrytitle>named-checkconf</refentrytitle> 481 <manvolnum>8</manvolnum> 482 </citerefentry>, 483 <citerefentry> 484 <refentrytitle>named-checkzone</refentrytitle> 485 <manvolnum>8</manvolnum> 486 </citerefentry>, 487 <citerefentry> 488 <refentrytitle>rndc</refentrytitle> 489 <manvolnum>8</manvolnum> 490 </citerefentry>, 491 <citerefentry> 492 <refentrytitle>lwresd</refentrytitle> 493 <manvolnum>8</manvolnum> 494 </citerefentry>, 495 <citerefentry> 496 <refentrytitle>named.conf</refentrytitle> 497 <manvolnum>5</manvolnum> 498 </citerefentry>, 499 <citetitle>BIND 9 Administrator Reference Manual</citetitle>. 500 </para> 501 </refsect1> 502 503 <refsect1> 504 <title>AUTHOR</title> 505 <para><corpauthor>Internet Systems Consortium</corpauthor> 506 </para> 507 </refsect1> 508 509</refentry><!-- 510 - Local variables: 511 - mode: sgml 512 - End: 513--> 514