1.. Copyright (C) Internet Systems Consortium, Inc. ("ISC") 2.. 3.. SPDX-License-Identifier: MPL-2.0 4.. 5.. This Source Code Form is subject to the terms of the Mozilla Public 6.. License, v. 2.0. If a copy of the MPL was not distributed with this 7.. file, you can obtain one at https://mozilla.org/MPL/2.0/. 8.. 9.. See the COPYRIGHT file distributed with this work for additional 10.. information regarding copyright ownership. 11 12.. _ns_operations: 13 14Name Server Operations 15---------------------- 16 17.. _tools: 18 19Tools for Use With the Name Server Daemon 20~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 21 22This section describes several indispensable diagnostic, administrative, 23and monitoring tools available to the system administrator for 24controlling and debugging the name server daemon. 25 26.. _diagnostic_tools: 27 28Diagnostic Tools 29^^^^^^^^^^^^^^^^ 30 31The :iscman:`dig`, :iscman:`host`, and :iscman:`nslookup` programs are all command-line 32tools for manually querying name servers. They differ in style and 33output format. 34 35:iscman:`dig` 36 :iscman:`dig` is the most versatile and complete of these lookup tools. It 37 has two modes: simple interactive mode for a single query, and batch 38 mode, which executes a query for each in a list of several query 39 lines. All query options are accessible from the command line. 40 41 For more information and a list of available commands and options, 42 see :ref:`man_dig`. 43 44:iscman:`host` 45 The :iscman:`host` utility emphasizes simplicity and ease of use. By 46 default, it converts between host names and Internet addresses, but 47 its functionality can be extended with the use of options. 48 49 For more information and a list of available commands and options, 50 see :ref:`man_host`. 51 52:iscman:`nslookup` 53 :iscman:`nslookup` has two modes: interactive and non-interactive. 54 Interactive mode allows the user to query name servers for 55 information about various hosts and domains, or to print a list of 56 hosts in a domain. Non-interactive mode is used to print just the 57 name and requested information for a host or domain. 58 59 Due to its arcane user interface and frequently inconsistent 60 behavior, we do not recommend the use of :iscman:`nslookup`. Use :iscman:`dig` 61 instead. 62 63.. _admin_tools: 64 65Administrative Tools 66^^^^^^^^^^^^^^^^^^^^ 67 68Administrative tools play an integral part in the management of a 69server. 70 71:iscman:`named-checkconf` 72 The :iscman:`named-checkconf` program checks the syntax of a :iscman:`named.conf` 73 file. 74 75 For more information and a list of available commands and options, 76 see :ref:`man_named-checkconf`. 77 78:iscman:`named-checkzone` 79 The :iscman:`named-checkzone` program checks a zone file for syntax and 80 consistency. 81 82 For more information and a list of available commands and options, 83 see :ref:`man_named-checkzone`. 84 85:iscman:`named-compilezone` 86 This tool is similar to :iscman:`named-checkzone` but it always dumps the zone content 87 to a specified file (typically in a different format). 88 89 For more information and a list of available commands and options, 90 see :ref:`man_named-compilezone`. 91 92.. _ops_rndc: 93 94:iscman:`rndc` 95 The remote name daemon control (:iscman:`rndc`) program allows the system 96 administrator to control the operation of a name server. 97 98 See :ref:`man_rndc` for details of the available :iscman:`rndc` 99 commands. 100 101 :iscman:`rndc` requires a configuration file, since all communication with 102 the server is authenticated with digital signatures that rely on a 103 shared secret, and there is no way to provide that secret other than 104 with a configuration file. The default location for the :iscman:`rndc` 105 configuration file is |rndc_conf|, but an alternate location 106 can be specified with the :option:`-c <rndc -c>` option. If the configuration file is 107 not found, :iscman:`rndc` also looks in |rndc_key| (or whatever 108 ``sysconfdir`` was defined when the BIND build was configured). The 109 ``rndc.key`` file is generated by running :option:`rndc-confgen -a` as 110 described in :any:`controls`. 111 112 The format of the configuration file is similar to that of 113 :iscman:`named.conf`, but is limited to only three blocks: the :rndcconf:ref:`options`, 114 :rndcconf:ref:`key`, :rndcconf:ref:`server`, and the :ref:`include_grammar`. These blocks are 115 what associate the secret keys to the servers with which they are 116 meant to be shared. The order of blocks is not significant. 117 118.. rndcconf:statement:: options 119 120 .. rndcconf:statement:: default-server 121 122 :any:`default-server` takes a 123 host name or address argument and represents the server that is 124 contacted if no :option:`-s <rndc -s>` option is provided on the command line. 125 126 .. rndcconf:statement:: default-key 127 128 :any:`default-key` takes the name of a key as its argument, as defined 129 by a :rndcconf:ref:`key` block. 130 131 .. rndcconf:statement:: default-port 132 133 :any:`default-port` specifies the port to which 134 :iscman:`rndc` should connect if no port is given on the command line or in 135 a :rndcconf:ref:`server` block. 136 137 .. rndcconf:statement:: default-source-address 138 .. rndcconf:statement:: default-source-address-v6 139 140 :any:`default-source-address` and :any:`default-source-address-v6` specify 141 the IPv4 and IPv6 source address used to communicate with the server 142 if no address is given on the command line or in a 143 :rndcconf:ref:`server` block. 144 145.. rndcconf:statement:: key 146 147 The :rndcconf:ref:`key` block defines a key to be used by :iscman:`rndc` when 148 authenticating with :iscman:`named`. Its syntax is identical to the :namedconf:ref:`key` 149 statement in :iscman:`named.conf`. The keyword :rndcconf:ref:`key` is followed by a key 150 name, which must be a valid domain name, though it need not actually 151 be hierarchical; thus, a string like ``rndc_key`` is a valid name. 152 The :rndcconf:ref:`key` block has two statements: :rndcconf:ref:`algorithm` and :rndcconf:ref:`secret`. 153 154 .. rndcconf:statement:: algorithm 155 156 While the configuration parser accepts any string as the argument 157 to :rndcconf:ref:`algorithm`, currently only the strings ``hmac-md5``, 158 ``hmac-sha1``, ``hmac-sha224``, ``hmac-sha256``, 159 ``hmac-sha384``, and ``hmac-sha512`` have any meaning. 160 161 .. rndcconf:statement:: secret 162 163 The secret 164 is a Base64-encoded string as specified in :rfc:`3548`. 165 166.. rndcconf:statement:: server 167 168 The :rndcconf:ref:`server` block specifies connection parameters for a given server. 169 The server can be specified as a host name or address. 170 171 .. rndcconf:statement:: addresses 172 173 Specifies one or more addresses to use when communicating with this 174 server. 175 176 :rndcconf:ref:`key` 177 Associates a key defined using the :rndcconf:ref:`key` statement with a 178 server. 179 180 .. rndcconf:statement:: port 181 182 Specifes the port :iscman:`rndc` should connect to on the server. 183 184 .. rndcconf:statement:: source-address 185 .. rndcconf:statement:: source-address-v6 186 187 Overrides :rndcconf:ref:`default-source-address` and 188 :rndcconf:ref:`default-source-address-v6` for this specific server. 189 190 A sample minimal configuration file is as follows: 191 192 :: 193 194 key rndc_key { 195 algorithm "hmac-sha256"; 196 secret 197 "c3Ryb25nIGVub3VnaCBmb3IgYSBtYW4gYnV0IG1hZGUgZm9yIGEgd29tYW4K"; 198 }; 199 options { 200 default-server 127.0.0.1; 201 default-key rndc_key; 202 }; 203 204 This file, if installed as |rndc_conf|, allows the 205 command: 206 207 :option:`rndc reload` 208 209 to connect to 127.0.0.1 port 953 and causes the name server to reload, 210 if a name server on the local machine is running with the following 211 controls statements: 212 213 :: 214 215 controls { 216 inet 127.0.0.1 217 allow { localhost; } keys { rndc_key; }; 218 }; 219 220 and it has an identical key block for ``rndc_key``. 221 222 Running the :iscman:`rndc-confgen` program conveniently creates an 223 :iscman:`rndc.conf` file, and also displays the corresponding 224 :any:`controls` statement needed to add to :iscman:`named.conf`. 225 Alternatively, it is possible to run :option:`rndc-confgen -a` to set up an 226 ``rndc.key`` file and not modify :iscman:`named.conf` at all. 227 228Signals 229~~~~~~~ 230 231Certain Unix signals cause the name server to take specific actions, as 232described in the following table. These signals can be sent using the 233``kill`` command. 234 235+--------------+-------------------------------------------------------------+ 236| ``SIGHUP`` | Causes the server to read :iscman:`named.conf` and reload | 237| | the database. | 238+--------------+-------------------------------------------------------------+ 239| ``SIGTERM`` | Causes the server to clean up and exit. | 240+--------------+-------------------------------------------------------------+ 241| ``SIGINT`` | Causes the server to clean up and exit. | 242+--------------+-------------------------------------------------------------+ 243 244