Bv9ARM.ch01.html revision 9b26804b581d11dc845e96073bda32f739581aee
1167fc7904c5f0a472f8df207ac46dd52c7f1ec8Automatic Updater>Introduction </TITLE
46da3117812814a29432a8d9a9ccf8acdbfdadceAutomatic UpdaterNAME="GENERATOR"
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ea854b585041ad19f70f7af15e08144ef2c2bd1bMark AndrewsREL="PREVIOUS"
90ff38a0d8deaf5f9c2aa5916d99b2e572d28738Automatic UpdaterTITLE="BIND Resource Requirements"
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9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian WellingtonBGCOLOR="#FFFFFF"
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aa9c561961e9d877946ebaa8795fa2be054ab7bfEvan HuntVALIGN="bottom"
aa9c561961e9d877946ebaa8795fa2be054ab7bfEvan HuntALIGN="center"
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9513a2a6670951f5cf5477fcfec9f933fcaff628Automatic UpdaterVALIGN="bottom"
eabc9c3c07cd956d3c436bd7614cb162dabdda76Mark AndrewsCLASS="chapter"
129090f0f6f91753b4a085ab635e28549fd018adAutomatic Updater>Chapter 1. Introduction </A
c651f15b30f1dae5cc2f00878fb5da5b3a35a468Mark Andrews>Table of Contents</B
c651f15b30f1dae5cc2f00878fb5da5b3a35a468Mark Andrews>Scope of Document</A
efb0e886f18894a1d2489f1ad74ad14b579e11c7Mark Andrews>Organization of This Document</A
91216cff91b34c9ff6e846dc23f248219cafe660Andreas Gustafsson>Conventions Used in This Document</A
b1265b5a06df36d490d4bdf54284fb133a1f5a84Automatic Updater>Discussion of Domain Name System (<SPAN
9174e44c14b1cb91a651fa1dc29470438c246ab9Automatic UpdaterCLASS="acronym"
0c39b3ed9409ecb277d5e32fa763a4e4d6598df8Automatic UpdaterCLASS="acronym"
08e3b6797706a13054bad749dea04e94b514b8e7Automatic Updater>The Internet Domain Name System (<SPAN
dd65eb1efb40b1c47d57963192bfc54873b219beAutomatic UpdaterCLASS="acronym"
995eaa289ba9709c64ef89b3776e53c36adc0010Automatic Updater>) consists of the syntax
b29e5c56eb74a6de1a84c29879afc90ffc6b1436Automatic Updater to specify the names of entities in the Internet in a hierarchical
418cc932318b1d67f88a36904d88d8a5a0a2ba09Automatic Updater manner, the rules used for delegating authority over names, and the
995eaa289ba9709c64ef89b3776e53c36adc0010Automatic Updater system implementation that actually maps names to Internet
c651f15b30f1dae5cc2f00878fb5da5b3a35a468Mark Andrews addresses. <SPAN
0977f3f39ef6728516be7976452b9122c8f5607aAutomatic UpdaterCLASS="acronym"
c651f15b30f1dae5cc2f00878fb5da5b3a35a468Mark Andrews> data is maintained in a group of distributed
0c39b3ed9409ecb277d5e32fa763a4e4d6598df8Automatic Updater hierarchical databases.</P
f2770f6b39a9b2a98afb7a11ed105f73f1570c1eAutomatic Updater>1.1. Scope of Document</A
f2770f6b39a9b2a98afb7a11ed105f73f1570c1eAutomatic Updater>The Berkeley Internet Name Domain (<SPAN
91216cff91b34c9ff6e846dc23f248219cafe660Andreas GustafssonCLASS="acronym"
aa1d397c4736cd86540555193d71e55fa3b37b2aMark Andrews>) implements an
91216cff91b34c9ff6e846dc23f248219cafe660Andreas Gustafsson Internet nameserver for a number of operating systems. This
dd65eb1efb40b1c47d57963192bfc54873b219beAutomatic Updater document provides basic information about the installation and
dd65eb1efb40b1c47d57963192bfc54873b219beAutomatic Updater care of the Internet Software Consortium (<SPAN
dd65eb1efb40b1c47d57963192bfc54873b219beAutomatic UpdaterCLASS="acronym"
133e6d43fa82e80d3798be4de00f4540f485ec6cAutomatic UpdaterCLASS="acronym"
f2770f6b39a9b2a98afb7a11ed105f73f1570c1eAutomatic Updater software package for system administrators.</P
e8c7dc2a5ce48f11c07a67c9923eeb8f419ff19fEvan HuntCLASS="sect1"
59528addd704f8d5757b54e540520f74e588a7c7Automatic Updater>1.2. Organization of This Document</A
19b3dc94bce93fa76bd7e066f9298630dbc9dcb4Automatic Updater>In this document, <I
d145b64cacc8d9cda51f9924ec70cd4661c3e2cfAutomatic UpdaterCLASS="emphasis"
9513a2a6670951f5cf5477fcfec9f933fcaff628Automatic Updater the basic <SPAN
c243d779731a410f8dc2d2feeed20c15f299b6e3Automatic UpdaterCLASS="acronym"
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic UpdaterCLASS="acronym"
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic UpdaterCLASS="emphasis"
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updater describes resource requirements for running <SPAN
7f79131f9a8e804b93c57f3c679065cce878b726Automatic UpdaterCLASS="acronym"
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updater environments. Information in <I
7f94d9a8162c9a96b56e66176702b66e79d8e1a2Automatic UpdaterCLASS="emphasis"
9513a2a6670951f5cf5477fcfec9f933fcaff628Automatic UpdaterCLASS="emphasis"
7f94d9a8162c9a96b56e66176702b66e79d8e1a2Automatic Updater>task-oriented</I
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updater> in its presentation and is
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updater organized functionally, to aid in the process of installing the
59528addd704f8d5757b54e540520f74e588a7c7Automatic UpdaterCLASS="acronym"
71bd43eebd9d6e42dbcae62b730f5b6508d5acd8Automatic Updater> 9 software. The task-oriented section is followed by
7262eb86f2b465822206122921e2f357218f0cfdAutomatic UpdaterCLASS="emphasis"
96ea71632887c58a9d00f47eb318bf76b35903c3Mark Andrews>Section 4</I
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updater>, which contains more advanced
9cd5eb6fe0f26d65724b99216cb31dcdd12e4afdAutomatic Updater concepts that the system administrator may need for implementing
bbb069be941f649228760edcc241122933c066d2Automatic Updater certain options. Section 5 describes the <SPAN
9cd5eb6fe0f26d65724b99216cb31dcdd12e4afdAutomatic UpdaterCLASS="acronym"
c651f15b30f1dae5cc2f00878fb5da5b3a35a468Mark Andrews> 9 lightweight
9cd5eb6fe0f26d65724b99216cb31dcdd12e4afdAutomatic Updater resolver. The contents of <I
80faf1588895fd26490f82f95a7a1b771df1c324Automatic UpdaterCLASS="emphasis"
c651f15b30f1dae5cc2f00878fb5da5b3a35a468Mark Andrews>Section 6</I
59528addd704f8d5757b54e540520f74e588a7c7Automatic Updater organized as in a reference manual to aid in the ongoing
c651f15b30f1dae5cc2f00878fb5da5b3a35a468Mark Andrews maintenance of the software. <I
c651f15b30f1dae5cc2f00878fb5da5b3a35a468Mark AndrewsCLASS="emphasis"
f7c88d61cc1ad2435b0b7cfaedfc9d5248c0be25Automatic Updater>addresses security considerations, and
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic UpdaterCLASS="emphasis"
b109432c3a939bff66a463be86c371bd88efe3aaAutomatic Updater> contains troubleshooting help. The
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updater main body of the document is followed by several
9cd5eb6fe0f26d65724b99216cb31dcdd12e4afdAutomatic UpdaterCLASS="emphasis"
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian Wellington> which contain useful reference
9cd5eb6fe0f26d65724b99216cb31dcdd12e4afdAutomatic Updater information, such as a <I
cf7e98f59148b559946a7f1ca728471374f1eef3Automatic UpdaterCLASS="emphasis"
96713299d08c0735c18ebe8772dd2cc1ecd4356aAutomatic Updater>Bibliography</I
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updater historic information related to <SPAN
cf7e98f59148b559946a7f1ca728471374f1eef3Automatic UpdaterCLASS="acronym"
91216cff91b34c9ff6e846dc23f248219cafe660Andreas Gustafsson> and the Domain Name
129090f0f6f91753b4a085ab635e28549fd018adAutomatic Updater>1.3. Conventions Used in This Document</A
9174e44c14b1cb91a651fa1dc29470438c246ab9Automatic Updater>In this document, we use the following general typographic
91216cff91b34c9ff6e846dc23f248219cafe660Andreas Gustafsson conventions:</P
56e7dc0c24b04210dcbffb180a9e35644fb820daAutomatic UpdaterCLASS="informaltable"
7d12a6b412fe47e6d6582923fd6954ab8cd0baebAutomatic UpdaterCLASS="CALSTABLE"
7d12a6b412fe47e6d6582923fd6954ab8cd0baebAutomatic UpdaterVALIGN="MIDDLE"
3351ccbd5c1961404044f8273d54dad405f53960Mark AndrewsCLASS="emphasis"
7d12a6b412fe47e6d6582923fd6954ab8cd0baebAutomatic UpdaterVALIGN="MIDDLE"
7d12a6b412fe47e6d6582923fd6954ab8cd0baebAutomatic UpdaterCLASS="emphasis"
7d12a6b412fe47e6d6582923fd6954ab8cd0baebAutomatic Updater>We use the style:</I
e8fc8c884b44371784805e1e0d3100da403dd3f1Automatic UpdaterVALIGN="MIDDLE"
e8fc8c884b44371784805e1e0d3100da403dd3f1Automatic Updater>a pathname, filename, URL, hostname,
e8fc8c884b44371784805e1e0d3100da403dd3f1Automatic Updatermailing list name, or new term or concept</P
9513a2a6670951f5cf5477fcfec9f933fcaff628Automatic UpdaterVALIGN="MIDDLE"
59528addd704f8d5757b54e540520f74e588a7c7Automatic UpdaterCLASS="filename"
7f79131f9a8e804b93c57f3c679065cce878b726Automatic UpdaterVALIGN="MIDDLE"
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian WellingtonVALIGN="MIDDLE"
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic UpdaterCLASS="userinput"
9cd5eb6fe0f26d65724b99216cb31dcdd12e4afdAutomatic Updater>Fixed Width Bold</B
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian WellingtonVALIGN="MIDDLE"
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian Wellington>variable user
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian WellingtonVALIGN="MIDDLE"
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian WellingtonCLASS="optional"
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian Wellington>Fixed Width Italic</SPAN
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian WellingtonVALIGN="MIDDLE"
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian Wellington>program output</P
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian WellingtonVALIGN="MIDDLE"
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian WellingtonCLASS="computeroutput"
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian Wellington>Fixed Width Bold</TT
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian Wellington>The following conventions are used in descriptions of the
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian WellingtonCLASS="acronym"
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian Wellington> configuration file:<DIV
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian WellingtonCLASS="informaltable"
ae7e54b14c946e0984c191554db9abb4893f9349Automatic UpdaterCLASS="CALSTABLE"
ae7e54b14c946e0984c191554db9abb4893f9349Automatic UpdaterVALIGN="MIDDLE"
ae7e54b14c946e0984c191554db9abb4893f9349Automatic UpdaterCLASS="emphasis"
aa1d397c4736cd86540555193d71e55fa3b37b2aMark AndrewsVALIGN="MIDDLE"
d4ef65050feac78554addf6e16a06c6e2e0bd331Brian WellingtonCLASS="emphasis"
aa1d397c4736cd86540555193d71e55fa3b37b2aMark Andrews>We use the style:</I
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian WellingtonVALIGN="MIDDLE"
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic UpdaterVALIGN="MIDDLE"
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic UpdaterCLASS="literal"
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updater>Sans Serif Bold</TT
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian WellingtonVALIGN="MIDDLE"
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian WellingtonVALIGN="MIDDLE"
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian WellingtonCLASS="varname"
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian Wellington>Sans Serif Italic</TT
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian WellingtonVALIGN="MIDDLE"
a26b22914b7bf25f065afb8cdef983766dcd672bAutomatic Updater>"meta-syntactic"
9cd5eb6fe0f26d65724b99216cb31dcdd12e4afdAutomatic Updaterinformation (within brackets when optional)</P
9cd5eb6fe0f26d65724b99216cb31dcdd12e4afdAutomatic UpdaterVALIGN="MIDDLE"
9cd5eb6fe0f26d65724b99216cb31dcdd12e4afdAutomatic UpdaterCLASS="optional"
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian Wellington>Fixed Width Italic</SPAN
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian WellingtonVALIGN="MIDDLE"
7adcb4de92bf4383a4c5624c4ed256736d02bc6dMark AndrewsVALIGN="MIDDLE"
7adcb4de92bf4383a4c5624c4ed256736d02bc6dMark AndrewsCLASS="userinput"
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian Wellington>Fixed Width Bold</B
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian WellingtonVALIGN="MIDDLE"
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian Wellington>Program output</P
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic UpdaterVALIGN="MIDDLE"
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic UpdaterCLASS="computeroutput"
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updater>Fixed Width</TT
7adcb4de92bf4383a4c5624c4ed256736d02bc6dMark AndrewsVALIGN="MIDDLE"
7adcb4de92bf4383a4c5624c4ed256736d02bc6dMark Andrews>Optional input</P
7adcb4de92bf4383a4c5624c4ed256736d02bc6dMark AndrewsVALIGN="MIDDLE"
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian WellingtonCLASS="optional"
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian Wellington>Text is enclosed in square brackets</SPAN
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updater>1.4. Discussion of Domain Name System (<SPAN
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic UpdaterCLASS="acronym"
b4cebdb6ccde66a8f3e397a1b90b0cf788519d69Automatic UpdaterCLASS="acronym"
068a66979695c77359e7a9181bb3f831c965b21cMark Andrews>The purpose of this document is to explain the installation
532d27b39244fadfcf8d8b4593f4c65434c9c664Automatic Updaterand basic upkeep of the <SPAN
47ff70af9e842bf0f69d209433995216f560fe4aAutomatic UpdaterCLASS="acronym"
532d27b39244fadfcf8d8b4593f4c65434c9c664Automatic Updater> software package, and we begin by reviewing
532d27b39244fadfcf8d8b4593f4c65434c9c664Automatic Updaterthe fundamentals of the domain naming system as they relate to <SPAN
532d27b39244fadfcf8d8b4593f4c65434c9c664Automatic UpdaterCLASS="acronym"
31a540386a9abaf681d8952f1b2cdf5c75a0ba6cAutomatic UpdaterCLASS="acronym"
31a540386a9abaf681d8952f1b2cdf5c75a0ba6cAutomatic Updater> consists of a <I
ff8ec39ce4afc2d774ce99f2386474d2c8539cd4Automatic UpdaterCLASS="emphasis"
ff8ec39ce4afc2d774ce99f2386474d2c8539cd4Automatic Updater> (or "daemon")
31a540386a9abaf681d8952f1b2cdf5c75a0ba6cAutomatic UpdaterCLASS="command"
31a540386a9abaf681d8952f1b2cdf5c75a0ba6cAutomatic UpdaterCLASS="command"
ff8ec39ce4afc2d774ce99f2386474d2c8539cd4Automatic UpdaterCLASS="acronym"
31a540386a9abaf681d8952f1b2cdf5c75a0ba6cAutomatic Updater> server runs in the background, servicing queries on a well
ff8ec39ce4afc2d774ce99f2386474d2c8539cd4Automatic Updaterknown network port. The standard port for the User Datagram Protocol
ff8ec39ce4afc2d774ce99f2386474d2c8539cd4Automatic Updater(UDP) and Transmission Control Protocol (TCP), usually port 53,
ff8ec39ce4afc2d774ce99f2386474d2c8539cd4Automatic Updateris specified in<B
ff8ec39ce4afc2d774ce99f2386474d2c8539cd4Automatic UpdaterCLASS="command"
31a540386a9abaf681d8952f1b2cdf5c75a0ba6cAutomatic UpdaterCLASS="filename"
31a540386a9abaf681d8952f1b2cdf5c75a0ba6cAutomatic UpdaterCLASS="emphasis"
31a540386a9abaf681d8952f1b2cdf5c75a0ba6cAutomatic Updater> is a set of routines residing
ff8ec39ce4afc2d774ce99f2386474d2c8539cd4Automatic Updaterin a system library that provides the interface that programs can
31a540386a9abaf681d8952f1b2cdf5c75a0ba6cAutomatic Updateruse to access the domain name services.</P
ff8ec39ce4afc2d774ce99f2386474d2c8539cd4Automatic Updater>1.4.1. Nameservers</A
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updater>A nameserver (NS) is a program that stores information about
d4ef65050feac78554addf6e16a06c6e2e0bd331Brian Wellingtonnamed resources and responds to queries from programs called <I
d4ef65050feac78554addf6e16a06c6e2e0bd331Brian WellingtonCLASS="emphasis"
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updateract as client processes. The basic function of an NS is to provide
d4ef65050feac78554addf6e16a06c6e2e0bd331Brian Wellingtoninformation about network objects by answering queries.</P
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updater>With the nameserver, the network can be broken into a hierarchy
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updaterof domains. The name space is organized as a tree according to organizational
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updateror administrative boundaries. Each node of the tree, called a domain,
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updateris given a label. The name of the domain is the concatenation of
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updaterall the labels of the domains from the root to the current domain.
47ff70af9e842bf0f69d209433995216f560fe4aAutomatic UpdaterThis is represented in written form as a string of labels listed
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updaterfrom right to left and separated by dots. A label need only be unique
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updaterwithin its domain. The whole name space is partitioned into areas
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic UpdaterCLASS="emphasis"
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updater>, each starting at a domain and
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updaterextending down to the leaf domains or to domains where other zones
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updaterstart. Zones usually represent administrative boundaries. For example,
47ff70af9e842bf0f69d209433995216f560fe4aAutomatic Updatera domain name for a host at the company <I
fd7c65dce9c2b1a3d12ca4df9074cd38019fdb5fAutomatic UpdaterCLASS="emphasis"
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updater>Example, Inc.</I
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic UpdaterCLASS="systemitem"
ff8ec39ce4afc2d774ce99f2386474d2c8539cd4Automatic UpdaterCLASS="systemitem"
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updater> is the top level domain to which <SPAN
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic UpdaterCLASS="systemitem"
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian Wellington> belongs, <SPAN
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic UpdaterCLASS="systemitem"
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updatera subdomain of <SPAN
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic UpdaterCLASS="systemitem"
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic UpdaterCLASS="systemitem"
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updatername of the host.</P
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updater>The specifications for the domain nameserver are defined in
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updaterthe RFC 1034, RFC 1035 and RFC 974. These documents can be found
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic UpdaterCLASS="filename"
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updater> in 4.4BSD or are available
4104e236f71eb5108fcfda6711878a97f6f4a8e7Automatic Updatervia File Transfer Protocol (FTP) from
fd7c65dce9c2b1a3d12ca4df9074cd38019fdb5fAutomatic Updater> or via the Web at <A
4104e236f71eb5108fcfda6711878a97f6f4a8e7Automatic Updater(See Appendix C for complete information on finding and retrieving
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic UpdaterRFCs.) It is also recommended that you read the related man pages: <B
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian WellingtonCLASS="command"
ae7e54b14c946e0984c191554db9abb4893f9349Automatic UpdaterCLASS="command"
2da2220fe7af2c45724b50b0187523b1fab0cf08Rob Austein>1.4.2. Types of Zones</A
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updater>As we stated previously, a zone is a point of delegation in
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic UpdaterCLASS="acronym"
7af91d15b2ce1ce32f7320f6d5cc3b83621c241aAutomatic Updater> tree. A zone consists of those contiguous parts of the domain
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updatertree for which a domain server has complete information and over which
ff8ec39ce4afc2d774ce99f2386474d2c8539cd4Automatic Updaterit has authority. It contains all domain names from a certain point
7af91d15b2ce1ce32f7320f6d5cc3b83621c241aAutomatic Updaterdownward in the domain tree except those which are delegated to
ff8ec39ce4afc2d774ce99f2386474d2c8539cd4Automatic Updaterother zones. A delegation point has one or more NS records in the
7af91d15b2ce1ce32f7320f6d5cc3b83621c241aAutomatic Updaterparent zone, which should be matched by equivalent NS records at
7af91d15b2ce1ce32f7320f6d5cc3b83621c241aAutomatic Updaterthe root of the delegated zone.</P
7af91d15b2ce1ce32f7320f6d5cc3b83621c241aAutomatic Updater>To properly operate a nameserver, it is important to understand
7af91d15b2ce1ce32f7320f6d5cc3b83621c241aAutomatic Updaterthe difference between a <I
7af91d15b2ce1ce32f7320f6d5cc3b83621c241aAutomatic UpdaterCLASS="emphasis"
4104e236f71eb5108fcfda6711878a97f6f4a8e7Automatic UpdaterCLASS="emphasis"
7af91d15b2ce1ce32f7320f6d5cc3b83621c241aAutomatic Updater>For instance, consider the <SPAN
ff8ec39ce4afc2d774ce99f2386474d2c8539cd4Automatic UpdaterCLASS="systemitem"
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian Wellingtonwhich includes names such as <SPAN
fd7c65dce9c2b1a3d12ca4df9074cd38019fdb5fAutomatic UpdaterCLASS="systemitem"
fd7c65dce9c2b1a3d12ca4df9074cd38019fdb5fAutomatic UpdaterCLASS="systemitem"
6c6a121295b30772cbf3dd75a51fb9d883051a0eAutomatic Updaterthough the <SPAN
6c6a121295b30772cbf3dd75a51fb9d883051a0eAutomatic UpdaterCLASS="systemitem"
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updater> zone includes only delegations
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian WellingtonCLASS="systemitem"
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian WellingtonCLASS="systemitem"
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic UpdaterA zone can map exactly to a single domain, but could also include
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian Wellingtononly part of a domain, the rest of which could be delegated to other
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updaternameservers. Every name in the <SPAN
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic UpdaterCLASS="acronym"
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic UpdaterCLASS="emphasis"
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updatereven if it is <I
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian WellingtonCLASS="emphasis"
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian Wellington>, that is, has no <I
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic UpdaterCLASS="emphasis"
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic UpdaterEvery subdomain is a domain and every domain except the root is
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updateralso a subdomain. The terminology is not intuitive and we suggest
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updaterthat you read RFCs 1033, 1034 and 1035 to gain a complete understanding
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updaterof this difficult and subtle topic.</P
7adcb4de92bf4383a4c5624c4ed256736d02bc6dMark AndrewsCLASS="acronym"
7a6ad11e0185a73984410f3252f3c49c3a301dbdBrian Wellington> is a Domain Nameserver, it deals primarily in
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updaterterms of zones. The master and slave declarations in the <TT
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic UpdaterCLASS="filename"
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updaterspecify zones, not domains. When you ask some other site if it is willing
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updaterto be a slave server for your <I
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic UpdaterCLASS="emphasis"
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian Wellingtonactually asking for slave service for some collection of zones.</P
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian Wellington>Each zone will have one <I
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian WellingtonCLASS="emphasis"
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updater>primary master</I
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic UpdaterCLASS="emphasis"
9cd5eb6fe0f26d65724b99216cb31dcdd12e4afdAutomatic Updater>) server which loads the zone
f65d2e1c04c806a185bf9f3120e80692f5ccd5e6Automatic Updatercontents from some local file edited by humans or perhaps generated
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian Wellingtonmechanically from some other local file which is edited by humans.
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic UpdaterThere there will be some number of <I
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic UpdaterCLASS="emphasis"
e062b72f783cdb436a1a57a630bdff471dbb3038Mark AndrewsCLASS="emphasis"
d145b64cacc8d9cda51f9924ec70cd4661c3e2cfAutomatic Updater>secondary) </I
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updater>servers, which load the zone
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updatercontents using the <SPAN
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic UpdaterCLASS="acronym"
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updater> protocol (that is, the secondary servers
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updaterwill contact the primary and fetch the zone data using TCP). This
3e79333aa37d3b88959372431a02af8a3eb7cfd9Automatic Updaterset of servers — the primary and all of its secondaries — should be
e076d0c88be69de7c190ab924d095e69d2e11f7aAndreas Gustafssonlisted in the NS records in the parent zone and will constitute a <I
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic UpdaterCLASS="emphasis"
aa1d397c4736cd86540555193d71e55fa3b37b2aMark Andrews>delegation</I
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic UpdaterThis set of servers must also be listed in the zone file itself,
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updaterusually under the <B
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic UpdaterCLASS="command"
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updater> name which indicates the <I
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic UpdaterCLASS="emphasis"
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic UpdaterCLASS="emphasis"
47ff70af9e842bf0f69d209433995216f560fe4aAutomatic Updater> of the current zone.
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic UpdaterYou can list servers in the zone's top-level <B
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic UpdaterCLASS="command"
31a540386a9abaf681d8952f1b2cdf5c75a0ba6cAutomatic Updaterrecords that are not in the parent's NS delegation, but you cannot
31a540386a9abaf681d8952f1b2cdf5c75a0ba6cAutomatic Updaterlist servers in the parent's delegation that are not present in
31a540386a9abaf681d8952f1b2cdf5c75a0ba6cAutomatic UpdaterCLASS="command"
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updater>Any servers listed in the NS records must be configured as <I
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic UpdaterCLASS="emphasis"
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian Wellington>authoritative</I
601c1908d06375f5dea00ab98671a6c934d8a840Automatic Updaterthe zone. A server is authoritative for a zone when it has been
601c1908d06375f5dea00ab98671a6c934d8a840Automatic Updaterconfigured to answer questions for that zone with authority, which
601c1908d06375f5dea00ab98671a6c934d8a840Automatic Updaterit does by setting the "authoritative answer" (AA) bit in reply
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updaterpackets. A server may be authoritative for more than one zone. The
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian Wellingtonauthoritative data for a zone is composed of all of the Resource
fd7c65dce9c2b1a3d12ca4df9074cd38019fdb5fAutomatic UpdaterRecords (RRs) — the data associated with names in a tree-structured
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updatername space — attached to all of the nodes from the top node of the
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updaterzone down to leaf nodes or nodes above cuts around the bottom edge
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian Wellingtonof the zone.</P
601c1908d06375f5dea00ab98671a6c934d8a840Automatic Updater>Adding a zone as a type master or type slave will tell the
aa1d397c4736cd86540555193d71e55fa3b37b2aMark Andrewsserver to answer questions for the zone authoritatively. If the
601c1908d06375f5dea00ab98671a6c934d8a840Automatic Updaterserver is able to load the zone into memory without any errors it
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian Wellingtonwill set the AA bit when it replies to queries for the zone. See
601c1908d06375f5dea00ab98671a6c934d8a840Automatic UpdaterRFCs 1034 and 1035 for more information about the AA bit.</P
c95f536d78842fbc8ebcef653d88e1f2270054f8Automatic Updater>1.4.3. Servers</A
f9119ad8f6114b2255e7545bf5cd187f4db0a89bAutomatic UpdaterCLASS="acronym"
f9119ad8f6114b2255e7545bf5cd187f4db0a89bAutomatic Updater> server can be master for some zones and slave for others
f9119ad8f6114b2255e7545bf5cd187f4db0a89bAutomatic Updateror can be only a master, or only a slave, or can serve no zones
c95f536d78842fbc8ebcef653d88e1f2270054f8Automatic Updaterand just answer queries via its <I
c95f536d78842fbc8ebcef653d88e1f2270054f8Automatic UpdaterCLASS="emphasis"
c95f536d78842fbc8ebcef653d88e1f2270054f8Automatic Updaterservers are often also called <I
c95f536d78842fbc8ebcef653d88e1f2270054f8Automatic UpdaterCLASS="emphasis"
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updaterslave servers are often also called <I
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian WellingtonCLASS="emphasis"
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updater>secondaries</I
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian WellingtonBoth master/primary and slave/secondary servers are authoritative
601c1908d06375f5dea00ab98671a6c934d8a840Automatic Updater>All servers keep data in their cache until the data expires,
601c1908d06375f5dea00ab98671a6c934d8a840Automatic Updaterbased on a Time To Live (TTL) field which is maintained for all
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updaterresource records.</P
53aed64e0f8553762fc0c380ee41cb42f514c7d5Brian Wellington>1.4.3.1. Master Server</A
6de27e27ad6056d7c049feb912df5a6b9a56d1b8Automatic UpdaterCLASS="emphasis"
53aed64e0f8553762fc0c380ee41cb42f514c7d5Brian Wellington>primary master server</I
6de27e27ad6056d7c049feb912df5a6b9a56d1b8Automatic Updater> is the ultimate
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updatersource of information about a domain. The primary master is an authoritative
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updaterserver configured to be the source of zone transfer for one or more
6de27e27ad6056d7c049feb912df5a6b9a56d1b8Automatic Updatersecondary servers. The primary master server obtains data for the
af3e516f771c8ba376a8cd954a7233badfce8cdcAutomatic Updaterzone from a file on disk.</P
7e1a8f402e3881388db37152f71c698cb1f1c426Mark AndrewsCLASS="sect3"
7e1a8f402e3881388db37152f71c698cb1f1c426Mark AndrewsCLASS="sect3"
7e1a8f402e3881388db37152f71c698cb1f1c426Mark AndrewsNAME="AEN206"
7e1a8f402e3881388db37152f71c698cb1f1c426Mark Andrews>1.4.3.2. Slave Server</A
7e1a8f402e3881388db37152f71c698cb1f1c426Mark AndrewsCLASS="emphasis"
7e1a8f402e3881388db37152f71c698cb1f1c426Mark Andrews>slave server</I
7e1a8f402e3881388db37152f71c698cb1f1c426Mark Andrews>, also called a <I
7e1a8f402e3881388db37152f71c698cb1f1c426Mark AndrewsCLASS="emphasis"
7e1a8f402e3881388db37152f71c698cb1f1c426Mark Andrews>, is an authoritative server that uses zone transfers from
7e1a8f402e3881388db37152f71c698cb1f1c426Mark Andrewsthe primary master server to retrieve the zone data. Optionally,
7e1a8f402e3881388db37152f71c698cb1f1c426Mark Andrewsthe slave server obtains zone data from a cache on disk. Slave servers
7e1a8f402e3881388db37152f71c698cb1f1c426Mark Andrewsprovide necessary redundancy. All secondary/slave servers are named
7e1a8f402e3881388db37152f71c698cb1f1c426Mark Andrewsin the NS RRs for the zone.</P
7e1a8f402e3881388db37152f71c698cb1f1c426Mark AndrewsCLASS="sect3"
af3e516f771c8ba376a8cd954a7233badfce8cdcAutomatic Updater>1.4.3.3. Caching Only Server</A
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updater>Some servers are <I
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic UpdaterCLASS="emphasis"
ff8ec39ce4afc2d774ce99f2386474d2c8539cd4Automatic Updater>caching only servers</I
ff8ec39ce4afc2d774ce99f2386474d2c8539cd4Automatic UpdaterThis means that the server caches the information that it receives
ff8ec39ce4afc2d774ce99f2386474d2c8539cd4Automatic Updaterand uses it until the data expires. A caching only server is a server
ff8ec39ce4afc2d774ce99f2386474d2c8539cd4Automatic Updaterthat is not authoritative for any zone. This server services queries
ff8ec39ce4afc2d774ce99f2386474d2c8539cd4Automatic Updaterand asks other servers, who have the authority, for the information
f55369d776907119cd8699a4119d9c80daa7cae4Mark AndrewsNAME="AEN215"
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updater>1.4.3.4. Forwarding Server</A
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian Wellington>Instead of interacting with the nameservers for the root and
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updaterother domains, a <I
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian WellingtonCLASS="emphasis"
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updater>forwarding server</I
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian Wellington> always forwards
fd7c65dce9c2b1a3d12ca4df9074cd38019fdb5fAutomatic Updaterqueries it cannot satisfy from its authoritative data or cache to
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian Wellingtona fixed list of other servers. The forwarded queries are also known
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic UpdaterCLASS="emphasis"
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updater>recursive queries</I
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updater>, the same type as a client would
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updatersend to a server. There may be one or more servers forwarded to,
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updaterand they are queried in turn until the list is exhausted or an answer
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian Wellingtonis found. A forwarding server is typically used when you do not
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian Wellingtonwish all the servers at a given site to interact with the rest of
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian Wellingtonthe Internet servers. A typical scenario would involve a number
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updaterof internal <SPAN
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic UpdaterCLASS="acronym"
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updater> servers and an Internet firewall. Servers unable
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updaterto pass packets through the firewall would forward to the server
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian Wellingtonthat can do it, and that server would query the Internet <SPAN
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic UpdaterCLASS="acronym"
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updateron the internal server's behalf. An added benefit of using the forwarding
73eb75dc212911e4da58a3ce0a4672d3910193ebBrian Wellingtonfeature is that the central machine develops a much more complete
9cd5eb6fe0f26d65724b99216cb31dcdd12e4afdAutomatic Updatercache of information that all the workstations can take advantage
133e6d43fa82e80d3798be4de00f4540f485ec6cAutomatic Updater>There is no prohibition against declaring a server to be a
73eb75dc212911e4da58a3ce0a4672d3910193ebBrian Wellingtonforwarder even though it has master and/or slave zones as well;
bbf7c3fd96ae5e02cb84743c581862e35327032aAutomatic Updaterthe effect will still be that anything in the local server's cache
133e6d43fa82e80d3798be4de00f4540f485ec6cAutomatic Updateror zones will be answered, and anything else will be forwarded using
6c6a121295b30772cbf3dd75a51fb9d883051a0eAutomatic Updaterthe forwarders list.</P
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian Wellington>1.4.3.5. Stealth Server</A
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic UpdaterCLASS="emphasis"
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updater>stealth server</I
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updater> is a server that answers
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updaterauthoritatively for a zone, but is not listed in that zone's NS
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updaterrecords. Stealth servers can be used as a way to centralize distribution
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updaterof a zone, without having to edit the zone on a remote nameserver.
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic UpdaterWhere the master file for a zone resides on a stealth server in
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic Updaterthis way, it is often referred to as a "hidden primary" configuration.
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian WellingtonStealth servers can also be a way to keep a local copy of a zone
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian Wellingtonfor rapid access to the zone's records, even if all "official" nameservers
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian Wellingtonfor the zone are inaccessible.</P
fd7c65dce9c2b1a3d12ca4df9074cd38019fdb5fAutomatic UpdaterCLASS="NAVFOOTER"
8227257b1c0224a7991e04bb79dc5059d5062dfbAndreas GustafssonCELLPADDING="0"
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic UpdaterCELLSPACING="0"
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian WellingtonALIGN="center"
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian WellingtonALIGN="center"
ce9cad6bb04869c5e94d9dc721032b25117f9210Automatic UpdaterCLASS="acronym"
9e3a7b0faf417a10f5f689edf288807b2d5eedc5Brian Wellington> Resource Requirements</TD