CINXE.COM

<!DOCTYPE html> <html class="client-nojs vector-feature-language-in-header-enabled vector-feature-language-in-main-page-header-disabled vector-feature-sticky-header-disabled vector-feature-page-tools-pinned-disabled vector-feature-toc-pinned-clientpref-1 vector-feature-main-menu-pinned-disabled vector-feature-limited-width-clientpref-1 vector-feature-limited-width-content-enabled vector-feature-custom-font-size-clientpref-1 vector-feature-appearance-pinned-clientpref-1 vector-feature-night-mode-enabled skin-theme-clientpref-day vector-toc-available" lang="zh" dir="ltr"> <head> <meta charset="UTF-8"> <title>无类别域间路由 - 维基百科，自由的百科全书</title> <script>(function(){var className="client-js vector-feature-language-in-header-enabled vector-feature-language-in-main-page-header-disabled vector-feature-sticky-header-disabled vector-feature-page-tools-pinned-disabled vector-feature-toc-pinned-clientpref-1 vector-feature-main-menu-pinned-disabled vector-feature-limited-width-clientpref-1 vector-feature-limited-width-content-enabled vector-feature-custom-font-size-clientpref-1 vector-feature-appearance-pinned-clientpref-1 vector-feature-night-mode-enabled skin-theme-clientpref-day vector-toc-available";var cookie=document.cookie.match(/(?:^|; )zhwikimwclientpreferences=([^;]+)/);if(cookie){cookie[1].split('%2C').forEach(function(pref){className=className.replace(new RegExp('(^| )'+pref.replace(/-clientpref-\w+$|[^\w-]+/g,'')+'-clientpref-\\w+( |$)'),'$1'+pref+'$2');});}document.documentElement.className=className;}());RLCONF={"wgBreakFrames":false,"wgSeparatorTransformTable":["",""],"wgDigitTransformTable":["",""],"wgDefaultDateFormat":"zh", "wgMonthNames":["","1月","2月","3月","4月","5月","6月","7月","8月","9月","10月","11月","12月"],"wgRequestId":"d99b3d5b-5b8f-49ef-af26-eaa8304f2fe3","wgCanonicalNamespace":"","wgCanonicalSpecialPageName":false,"wgNamespaceNumber":0,"wgPageName":"无类别域间路由","wgTitle":"无类别域间路由","wgCurRevisionId":79295521,"wgRevisionId":79295521,"wgArticleId":939212,"wgIsArticle":true,"wgIsRedirect":false,"wgAction":"view","wgUserName":null,"wgUserGroups":["*"],"wgCategories":["自2018年8月需要從外語維基百科翻譯的條目","需要從外語維基百科翻譯的條目","自2018年8月待更新条目","含有多个问题的条目","含有英語的條目","自2013年2月有未列明来源语句的条目","使用RFC魔术链接的页面","互联网标准","互联网结构","路由","IP地址"],"wgPageViewLanguage":"zh","wgPageContentLanguage":"zh","wgPageContentModel":"wikitext","wgRelevantPageName":"无类别域间路由","wgRelevantArticleId":939212, "wgUserVariant":"zh","wgIsProbablyEditable":true,"wgRelevantPageIsProbablyEditable":true,"wgRestrictionEdit":[],"wgRestrictionMove":[],"wgNoticeProject":"wikipedia","wgCiteReferencePreviewsActive":true,"wgMediaViewerOnClick":true,"wgMediaViewerEnabledByDefault":true,"wgPopupsFlags":0,"wgVisualEditor":{"pageLanguageCode":"zh","pageLanguageDir":"ltr","pageVariantFallbacks":["zh-hans","zh-hant","zh-cn","zh-tw","zh-hk","zh-sg","zh-mo","zh-my"]},"wgMFDisplayWikibaseDescriptions":{"search":true,"watchlist":true,"tagline":true,"nearby":true},"wgWMESchemaEditAttemptStepOversample":false,"wgWMEPageLength":20000,"wgRelatedArticlesCompat":[],"wgCentralAuthMobileDomain":false,"wgEditSubmitButtonLabelPublish":true,"wgULSPosition":"interlanguage","wgULSisCompactLinksEnabled":false,"wgVector2022LanguageInHeader":true,"wgULSisLanguageSelectorEmpty":false,"wgWikibaseItemId":"Q646589","wgCheckUserClientHintsHeadersJsApi":["brands","architecture","bitness","fullVersionList","mobile","model","platform", "platformVersion"],"GEHomepageSuggestedEditsEnableTopics":true,"wgGETopicsMatchModeEnabled":false,"wgGEStructuredTaskRejectionReasonTextInputEnabled":false,"wgGELevelingUpEnabledForUser":false};RLSTATE={"ext.gadget.large-font":"ready","ext.globalCssJs.user.styles":"ready","site.styles":"ready","user.styles":"ready","ext.globalCssJs.user":"ready","user":"ready","user.options":"loading","ext.cite.styles":"ready","ext.math.styles":"ready","skins.vector.search.codex.styles":"ready","skins.vector.styles":"ready","skins.vector.icons":"ready","jquery.makeCollapsible.styles":"ready","ext.wikimediamessages.styles":"ready","ext.visualEditor.desktopArticleTarget.noscript":"ready","ext.uls.interlanguage":"ready","wikibase.client.init":"ready","ext.wikimediaBadges":"ready"};RLPAGEMODULES=["ext.cite.ux-enhancements","mediawiki.page.media","site","mediawiki.page.ready","jquery.makeCollapsible","mediawiki.toc","skins.vector.js","ext.centralNotice.geoIP","ext.centralNotice.startUp","ext.gadget.edit0", "ext.gadget.WikiMiniAtlas","ext.gadget.UnihanTooltips","ext.gadget.Difflink","ext.gadget.pseudonamespace-UI","ext.gadget.SpecialWikitext","ext.gadget.switcher","ext.gadget.VariantAlly","ext.gadget.AdvancedSiteNotices","ext.gadget.hideConversionTab","ext.gadget.internalLinkHelper-altcolor","ext.gadget.noteTA","ext.gadget.NavFrame","ext.gadget.collapsibleTables","ext.gadget.scrollUpButton","ext.urlShortener.toolbar","ext.centralauth.centralautologin","mmv.bootstrap","ext.popups","ext.visualEditor.desktopArticleTarget.init","ext.visualEditor.targetLoader","ext.echo.centralauth","ext.eventLogging","ext.wikimediaEvents","ext.navigationTiming","ext.uls.interface","ext.cx.eventlogging.campaigns","ext.cx.uls.quick.actions","wikibase.client.vector-2022","ext.checkUser.clientHints","ext.growthExperiments.SuggestedEditSession","wikibase.sidebar.tracking"];</script> <script>(RLQ=window.RLQ||[]).push(function(){mw.loader.impl(function(){return["user.options@12s5i",function($,jQuery,require,module){mw.user.tokens.set({"patrolToken":"+\\","watchToken":"+\\","csrfToken":"+\\"}); }];});});</script> <link rel="stylesheet" href="/w/load.php?lang=zh&modules=ext.cite.styles%7Cext.math.styles%7Cext.uls.interlanguage%7Cext.visualEditor.desktopArticleTarget.noscript%7Cext.wikimediaBadges%7Cext.wikimediamessages.styles%7Cjquery.makeCollapsible.styles%7Cskins.vector.icons%2Cstyles%7Cskins.vector.search.codex.styles%7Cwikibase.client.init&only=styles&skin=vector-2022"> <script async="" src="/w/load.php?lang=zh&modules=startup&only=scripts&raw=1&skin=vector-2022"></script> <meta name="ResourceLoaderDynamicStyles" content=""> <link rel="stylesheet" href="/w/load.php?lang=zh&modules=ext.gadget.large-font&only=styles&skin=vector-2022"> <link rel="stylesheet" href="/w/load.php?lang=zh&modules=site.styles&only=styles&skin=vector-2022"> <meta name="generator" content="MediaWiki 1.44.0-wmf.4"> <meta name="referrer" content="origin"> <meta name="referrer" content="origin-when-cross-origin"> <meta name="robots" content="max-image-preview:standard"> <meta name="format-detection" content="telephone=no"> <meta name="viewport" content="width=1120"> <meta property="og:title" content="无类别域间路由 - 维基百科，自由的百科全书"> <meta property="og:type" content="website"> <link rel="preconnect" href="//upload.wikimedia.org"> <link rel="alternate" media="only screen and (max-width: 640px)" href="//zh.m.wikipedia.org/wiki/%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1"> <link rel="alternate" type="application/x-wiki" title="编辑本页" href="/w/index.php?title=%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1&action=edit"> <link rel="apple-touch-icon" href="/static/apple-touch/wikipedia.png"> <link rel="icon" href="/static/favicon/wikipedia.ico"> <link rel="search" type="application/opensearchdescription+xml" href="/w/rest.php/v1/search" title="Wikipedia (zh)"> <link rel="EditURI" type="application/rsd+xml" href="//zh.wikipedia.org/w/api.php?action=rsd"> <link rel="canonical" href="https://zh.wikipedia.org/wiki/%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1"> <link rel="alternate" hreflang="zh" href="https://zh.wikipedia.org/wiki/%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1"> <link rel="alternate" hreflang="zh-Hans" href="https://zh.wikipedia.org/zh-hans/%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1"> <link rel="alternate" hreflang="zh-Hans-CN" href="https://zh.wikipedia.org/zh-cn/%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1"> <link rel="alternate" hreflang="zh-Hans-MY" href="https://zh.wikipedia.org/zh-my/%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1"> <link rel="alternate" hreflang="zh-Hans-SG" href="https://zh.wikipedia.org/zh-sg/%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1"> <link rel="alternate" hreflang="zh-Hant" href="https://zh.wikipedia.org/zh-hant/%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1"> <link rel="alternate" hreflang="zh-Hant-HK" href="https://zh.wikipedia.org/zh-hk/%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1"> <link rel="alternate" hreflang="zh-Hant-MO" href="https://zh.wikipedia.org/zh-mo/%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1"> <link rel="alternate" hreflang="zh-Hant-TW" href="https://zh.wikipedia.org/zh-tw/%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1"> <link rel="alternate" hreflang="x-default" href="https://zh.wikipedia.org/wiki/%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1"> <link rel="license" href="https://creativecommons.org/licenses/by-sa/4.0/deed.zh"> <link rel="alternate" type="application/atom+xml" title="Wikipedia的Atom feed" href="/w/index.php?title=Special:%E6%9C%80%E8%BF%91%E6%9B%B4%E6%94%B9&feed=atom"> <link rel="dns-prefetch" href="//meta.wikimedia.org" /> <link rel="dns-prefetch" href="//login.wikimedia.org"> </head> <body class="skin--responsive skin-vector skin-vector-search-vue mediawiki ltr sitedir-ltr mw-hide-empty-elt ns-0 ns-subject mw-editable page-无类别域间路由 rootpage-无类别域间路由 skin-vector-2022 action-view"><a class="mw-jump-link" href="#bodyContent">跳转到内容</a> <div class="vector-header-container"> <header class="vector-header mw-header"> <div class="vector-header-start"> <nav class="vector-main-menu-landmark" aria-label="站点"> <div id="vector-main-menu-dropdown" class="vector-dropdown vector-main-menu-dropdown vector-button-flush-left vector-button-flush-right" > <input type="checkbox" id="vector-main-menu-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-main-menu-dropdown" class="vector-dropdown-checkbox " aria-label="主菜单" > <label id="vector-main-menu-dropdown-label" for="vector-main-menu-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-menu mw-ui-icon-wikimedia-menu"></span> <span class="vector-dropdown-label-text">主菜单</span> </label> <div class="vector-dropdown-content"> <div id="vector-main-menu-unpinned-container" class="vector-unpinned-container"> <div id="vector-main-menu" class="vector-main-menu vector-pinnable-element"> <div class="vector-pinnable-header vector-main-menu-pinnable-header vector-pinnable-header-unpinned" data-feature-name="main-menu-pinned" data-pinnable-element-id="vector-main-menu" data-pinned-container-id="vector-main-menu-pinned-container" data-unpinned-container-id="vector-main-menu-unpinned-container" > <div class="vector-pinnable-header-label">主菜单</div> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-main-menu.pin">移至侧栏</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-main-menu.unpin">隐藏</button> </div> <div id="p-navigation" class="vector-menu mw-portlet mw-portlet-navigation" > <div class="vector-menu-heading"> 导航 </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="n-mainpage-description" class="mw-list-item"><a href="/wiki/Wikipedia:%E9%A6%96%E9%A1%B5" title="访问首页[z]" accesskey="z"><span>首页</span></a></li><li id="n-indexpage" class="mw-list-item"><a href="/wiki/Wikipedia:%E5%88%86%E7%B1%BB%E7%B4%A2%E5%BC%95" title="以分类索引搜寻中文维基百科"><span>分类索引</span></a></li><li id="n-Featured_content" class="mw-list-item"><a href="/wiki/Portal:%E7%89%B9%E8%89%B2%E5%85%A7%E5%AE%B9" title="查看中文维基百科的特色内容"><span>特色内容</span></a></li><li id="n-currentevents" class="mw-list-item"><a href="/wiki/Portal:%E6%96%B0%E8%81%9E%E5%8B%95%E6%85%8B" title="提供当前新闻事件的背景资料"><span>新闻动态</span></a></li><li id="n-recentchanges" class="mw-list-item"><a href="/wiki/Special:%E6%9C%80%E8%BF%91%E6%9B%B4%E6%94%B9" title="列出维基百科中的最近修改[r]" accesskey="r"><span>最近更改</span></a></li><li id="n-randompage" class="mw-list-item"><a href="/wiki/Special:%E9%9A%8F%E6%9C%BA%E9%A1%B5%E9%9D%A2" title="随机载入一个页面[x]" accesskey="x"><span>随机条目</span></a></li> </ul> </div> </div> <div id="p-help" class="vector-menu mw-portlet mw-portlet-help" > <div class="vector-menu-heading"> 帮助 </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="n-help" class="mw-list-item"><a href="/wiki/Help:%E7%9B%AE%E5%BD%95" title="寻求帮助"><span>帮助</span></a></li><li id="n-portal" class="mw-list-item"><a href="/wiki/Wikipedia:%E7%A4%BE%E7%BE%A4%E9%A6%96%E9%A1%B5" title="关于本计划、你可以做什么、应该如何做"><span>维基社群</span></a></li><li id="n-policy" class="mw-list-item"><a href="/wiki/Wikipedia:%E6%96%B9%E9%87%9D%E8%88%87%E6%8C%87%E5%BC%95" title="查看维基百科的方针和指引"><span>方针与指引</span></a></li><li id="n-villagepump" class="mw-list-item"><a href="/wiki/Wikipedia:%E4%BA%92%E5%8A%A9%E5%AE%A2%E6%A0%88" title="参与维基百科社群的讨论"><span>互助客栈</span></a></li><li id="n-Information_desk" class="mw-list-item"><a href="/wiki/Wikipedia:%E7%9F%A5%E8%AF%86%E9%97%AE%E7%AD%94" title="解答任何与维基百科无关的问题的地方"><span>知识问答</span></a></li><li id="n-conversion" class="mw-list-item"><a href="/wiki/Wikipedia:%E5%AD%97%E8%AF%8D%E8%BD%AC%E6%8D%A2" title="提出字词转换请求"><span>字词转换</span></a></li><li id="n-IRC" class="mw-list-item"><a href="/wiki/Wikipedia:IRC%E8%81%8A%E5%A4%A9%E9%A2%91%E9%81%93"><span>IRC即时聊天</span></a></li><li id="n-contact" class="mw-list-item"><a href="/wiki/Wikipedia:%E8%81%94%E7%BB%9C%E6%88%91%E4%BB%AC" title="如何联络维基百科"><span>联络我们</span></a></li><li id="n-about" class="mw-list-item"><a href="/wiki/Wikipedia:%E5%85%B3%E4%BA%8E" title="查看维基百科的简介"><span>关于维基百科</span></a></li> </ul> </div> </div> </div> </div> </div> </div> </nav> <a href="/wiki/Wikipedia:%E9%A6%96%E9%A1%B5" class="mw-logo"> <img class="mw-logo-icon" src="/static/images/icons/wikipedia.png" alt="" aria-hidden="true" height="50" width="50"> <span class="mw-logo-container skin-invert"> <img class="mw-logo-wordmark" alt="维基百科" src="/static/images/mobile/copyright/wikipedia-wordmark-zh.svg" style="width: 6.5625em; height: 1.375em;"> <img class="mw-logo-tagline" alt="自由的百科全书" src="/static/images/mobile/copyright/wikipedia-tagline-zh.svg" width="103" height="14" style="width: 6.4375em; height: 0.875em;"> </span> </a> </div> <div class="vector-header-end"> <div id="p-search" role="search" class="vector-search-box-vue vector-search-box-collapses vector-search-box-show-thumbnail vector-search-box-auto-expand-width vector-search-box"> <a href="/wiki/Special:%E6%90%9C%E7%B4%A2" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only search-toggle" title="搜索维基百科[f]" accesskey="f"><span class="vector-icon mw-ui-icon-search mw-ui-icon-wikimedia-search"></span> <span>搜索</span> </a> <div class="vector-typeahead-search-container"> <div class="cdx-typeahead-search cdx-typeahead-search--show-thumbnail cdx-typeahead-search--auto-expand-width"> <form action="/w/index.php" id="searchform" class="cdx-search-input cdx-search-input--has-end-button"> <div id="simpleSearch" class="cdx-search-input__input-wrapper" data-search-loc="header-moved"> <div class="cdx-text-input cdx-text-input--has-start-icon"> <input class="cdx-text-input__input" type="search" name="search" placeholder="搜索维基百科" aria-label="搜索维基百科" autocapitalize="sentences" title="搜索维基百科[f]" accesskey="f" id="searchInput" > <span class="cdx-text-input__icon cdx-text-input__start-icon"></span> </div> <input type="hidden" name="title" value="Special:搜索"> </div> <button class="cdx-button cdx-search-input__end-button">搜索</button> </form> </div> </div> </div> <nav class="vector-user-links vector-user-links-wide" aria-label="个人工具"> <div class="vector-user-links-main"> <div id="p-vector-user-menu-preferences" class="vector-menu mw-portlet emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> <div id="p-vector-user-menu-userpage" class="vector-menu mw-portlet emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> <nav class="vector-appearance-landmark" aria-label="外观"> <div id="vector-appearance-dropdown" class="vector-dropdown " title="更改页面字体大小、宽度和颜色的外观" > <input type="checkbox" id="vector-appearance-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-appearance-dropdown" class="vector-dropdown-checkbox " aria-label="外观" > <label id="vector-appearance-dropdown-label" for="vector-appearance-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-appearance mw-ui-icon-wikimedia-appearance"></span> <span class="vector-dropdown-label-text">外观</span> </label> <div class="vector-dropdown-content"> <div id="vector-appearance-unpinned-container" class="vector-unpinned-container"> </div> </div> </div> </nav> <div id="p-vector-user-menu-notifications" class="vector-menu mw-portlet emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> <div id="p-vector-user-menu-overflow" class="vector-menu mw-portlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="pt-sitesupport-2" class="user-links-collapsible-item mw-list-item user-links-collapsible-item"><a data-mw="interface" href="https://donate.wikimedia.org/?utm_source=donate&utm_medium=sidebar&utm_campaign=spontaneous&uselang=zh-hans" class=""><span>资助维基百科</span></a> </li> <li id="pt-createaccount-2" class="user-links-collapsible-item mw-list-item user-links-collapsible-item"><a data-mw="interface" href="/w/index.php?title=Special:%E5%88%9B%E5%BB%BA%E8%B4%A6%E6%88%B7&returnto=%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1" title="我们推荐您创建账号并登录，但这不是强制性的" class=""><span>创建账号</span></a> </li> <li id="pt-login-2" class="user-links-collapsible-item mw-list-item user-links-collapsible-item"><a data-mw="interface" href="/w/index.php?title=Special:%E7%94%A8%E6%88%B7%E7%99%BB%E5%BD%95&returnto=%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1" title="建议你登录，尽管并非必须。[o]" accesskey="o" class=""><span>登录</span></a> </li> </ul> </div> </div> </div> <div id="vector-user-links-dropdown" class="vector-dropdown vector-user-menu vector-button-flush-right vector-user-menu-logged-out" title="更多选项" > <input type="checkbox" id="vector-user-links-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-user-links-dropdown" class="vector-dropdown-checkbox " aria-label="个人工具" > <label id="vector-user-links-dropdown-label" for="vector-user-links-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-ellipsis mw-ui-icon-wikimedia-ellipsis"></span> <span class="vector-dropdown-label-text">个人工具</span> </label> <div class="vector-dropdown-content"> <div id="p-personal" class="vector-menu mw-portlet mw-portlet-personal user-links-collapsible-item" title="用户菜单" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="pt-sitesupport" class="user-links-collapsible-item mw-list-item"><a href="https://donate.wikimedia.org/?utm_source=donate&utm_medium=sidebar&utm_campaign=spontaneous&uselang=zh-hans"><span>资助维基百科</span></a></li><li id="pt-createaccount" class="user-links-collapsible-item mw-list-item"><a href="/w/index.php?title=Special:%E5%88%9B%E5%BB%BA%E8%B4%A6%E6%88%B7&returnto=%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1" title="我们推荐您创建账号并登录，但这不是强制性的"><span class="vector-icon mw-ui-icon-userAdd mw-ui-icon-wikimedia-userAdd"></span> <span>创建账号</span></a></li><li id="pt-login" class="user-links-collapsible-item mw-list-item"><a href="/w/index.php?title=Special:%E7%94%A8%E6%88%B7%E7%99%BB%E5%BD%95&returnto=%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1" title="建议你登录，尽管并非必须。[o]" accesskey="o"><span class="vector-icon mw-ui-icon-logIn mw-ui-icon-wikimedia-logIn"></span> <span>登录</span></a></li> </ul> </div> </div> <div id="p-user-menu-anon-editor" class="vector-menu mw-portlet mw-portlet-user-menu-anon-editor" > <div class="vector-menu-heading"> 未登录编辑者的页面 <a href="/wiki/Help:%E6%96%B0%E6%89%8B%E5%85%A5%E9%97%A8" aria-label="了解有关编辑的更多信息"><span>了解详情</span></a> </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="pt-anoncontribs" class="mw-list-item"><a href="/wiki/Special:%E6%88%91%E7%9A%84%E8%B4%A1%E7%8C%AE" title="来自此IP地址的编辑列表[y]" accesskey="y"><span>贡献</span></a></li><li id="pt-anontalk" class="mw-list-item"><a href="/wiki/Special:%E6%88%91%E7%9A%84%E8%AE%A8%E8%AE%BA%E9%A1%B5" title="对于来自此IP地址编辑的讨论[n]" accesskey="n"><span>讨论</span></a></li> </ul> </div> </div> </div> </div> </nav> </div> </header> </div> <div class="mw-page-container"> <div class="mw-page-container-inner"> <div class="vector-sitenotice-container"> <div id="siteNotice"></div> </div> <div class="vector-column-start"> <div class="vector-main-menu-container"> <div id="mw-navigation"> <nav id="mw-panel" class="vector-main-menu-landmark" aria-label="站点"> <div id="vector-main-menu-pinned-container" class="vector-pinned-container"> </div> </nav> </div> </div> <div class="vector-sticky-pinned-container"> <nav id="mw-panel-toc" aria-label="目录" data-event-name="ui.sidebar-toc" class="mw-table-of-contents-container vector-toc-landmark"> <div id="vector-toc-pinned-container" class="vector-pinned-container"> <div id="vector-toc" class="vector-toc vector-pinnable-element"> <div class="vector-pinnable-header vector-toc-pinnable-header vector-pinnable-header-pinned" data-feature-name="toc-pinned" data-pinnable-element-id="vector-toc" > <h2 class="vector-pinnable-header-label">目录</h2> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-toc.pin">移至侧栏</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-toc.unpin">隐藏</button> </div> <ul class="vector-toc-contents" id="mw-panel-toc-list"> <li id="toc-mw-content-text" class="vector-toc-list-item vector-toc-level-1"> <a href="#" class="vector-toc-link"> <div class="vector-toc-text">序言</div> </a> </li> <li id="toc-CIDR块" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#CIDR块"> <div class="vector-toc-text"> <span class="vector-toc-numb">1</span> <span>CIDR块</span> </div> </a> <ul id="toc-CIDR块-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-CIDR块的分配" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#CIDR块的分配"> <div class="vector-toc-text"> <span class="vector-toc-numb">2</span> <span>CIDR块的分配</span> </div> </a> <ul id="toc-CIDR块的分配-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-CIDR和掩码" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#CIDR和掩码"> <div class="vector-toc-text"> <span class="vector-toc-numb">3</span> <span>CIDR和掩码</span> </div> </a> <ul id="toc-CIDR和掩码-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-前缀聚合" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#前缀聚合"> <div class="vector-toc-text"> <span class="vector-toc-numb">4</span> <span>前缀聚合</span> </div> </a> <ul id="toc-前缀聚合-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-IPv6的CIDR块" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#IPv6的CIDR块"> <div class="vector-toc-text"> <span class="vector-toc-numb">5</span> <span>IPv6的CIDR块</span> </div> </a> <ul id="toc-IPv6的CIDR块-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-历史背景" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#历史背景"> <div class="vector-toc-text"> <span class="vector-toc-numb">6</span> <span>历史背景</span> </div> </a> <ul id="toc-历史背景-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-外部链接" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#外部链接"> <div class="vector-toc-text"> <span class="vector-toc-numb">7</span> <span>外部链接</span> </div> </a> <ul id="toc-外部链接-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-参考文献" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#参考文献"> <div class="vector-toc-text"> <span class="vector-toc-numb">8</span> <span>参考文献</span> </div> </a> <ul id="toc-参考文献-sublist" class="vector-toc-list"> </ul> </li> </ul> </div> </div> </nav> </div> </div> <div class="mw-content-container"> <main id="content" class="mw-body"> <header class="mw-body-header vector-page-titlebar"> <nav aria-label="目录" class="vector-toc-landmark"> <div id="vector-page-titlebar-toc" class="vector-dropdown vector-page-titlebar-toc vector-button-flush-left" > <input type="checkbox" id="vector-page-titlebar-toc-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-page-titlebar-toc" class="vector-dropdown-checkbox " aria-label="开关目录" > <label id="vector-page-titlebar-toc-label" for="vector-page-titlebar-toc-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-listBullet mw-ui-icon-wikimedia-listBullet"></span> <span class="vector-dropdown-label-text">开关目录</span> </label> <div class="vector-dropdown-content"> <div id="vector-page-titlebar-toc-unpinned-container" class="vector-unpinned-container"> </div> </div> </div> </nav> <h1 id="firstHeading" class="firstHeading mw-first-heading"><span class="mw-page-title-main">无类别域间路由</span></h1> <div id="p-lang-btn" class="vector-dropdown mw-portlet mw-portlet-lang" > <input type="checkbox" id="p-lang-btn-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-p-lang-btn" class="vector-dropdown-checkbox mw-interlanguage-selector" aria-label="前往另一种语言写成的文章。27种语言可用" > <label id="p-lang-btn-label" for="p-lang-btn-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--action-progressive mw-portlet-lang-heading-27" aria-hidden="true" ><span class="vector-icon mw-ui-icon-language-progressive mw-ui-icon-wikimedia-language-progressive"></span> <span class="vector-dropdown-label-text">27种语言</span> </label> <div class="vector-dropdown-content"> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li class="interlanguage-link interwiki-an mw-list-item"><a href="https://an.wikipedia.org/wiki/Classless_Inter-Domain_Routing" title="Classless Inter-Domain Routing – 阿拉贡语" lang="an" hreflang="an" data-title="Classless Inter-Domain Routing" data-language-autonym="Aragonés" data-language-local-name="阿拉贡语" class="interlanguage-link-target"><span>Aragonés</span></a></li><li class="interlanguage-link interwiki-ar mw-list-item"><a href="https://ar.wikipedia.org/wiki/%D8%AA%D9%88%D8%AC%D9%8A%D9%87_%D8%A8%D9%8A%D9%86_%D9%86%D8%B7%D8%A7%D9%82%D9%8A_%D8%BA%D9%8A%D8%B1_%D8%B5%D9%86%D9%81%D9%8A" title="توجيه بين نطاقي غير صنفي – 阿拉伯语" lang="ar" hreflang="ar" data-title="توجيه بين نطاقي غير صنفي" data-language-autonym="العربية" data-language-local-name="阿拉伯语" class="interlanguage-link-target"><span>العربية</span></a></li><li class="interlanguage-link interwiki-ca mw-list-item"><a href="https://ca.wikipedia.org/wiki/Classless_Inter-Domain_Routing" title="Classless Inter-Domain Routing – 加泰罗尼亚语" lang="ca" hreflang="ca" data-title="Classless Inter-Domain Routing" data-language-autonym="Català" data-language-local-name="加泰罗尼亚语" class="interlanguage-link-target"><span>Català</span></a></li><li class="interlanguage-link interwiki-cs mw-list-item"><a href="https://cs.wikipedia.org/wiki/Classless_Inter-Domain_Routing" title="Classless Inter-Domain Routing – 捷克语" lang="cs" hreflang="cs" data-title="Classless Inter-Domain Routing" data-language-autonym="Čeština" data-language-local-name="捷克语" class="interlanguage-link-target"><span>Čeština</span></a></li><li class="interlanguage-link interwiki-de mw-list-item"><a href="https://de.wikipedia.org/wiki/Classless_Inter-Domain_Routing" title="Classless Inter-Domain Routing – 德语" lang="de" hreflang="de" data-title="Classless Inter-Domain Routing" data-language-autonym="Deutsch" data-language-local-name="德语" class="interlanguage-link-target"><span>Deutsch</span></a></li><li class="interlanguage-link interwiki-en mw-list-item"><a href="https://en.wikipedia.org/wiki/Classless_Inter-Domain_Routing" title="Classless Inter-Domain Routing – 英语" lang="en" hreflang="en" data-title="Classless Inter-Domain Routing" data-language-autonym="English" data-language-local-name="英语" class="interlanguage-link-target"><span>English</span></a></li><li class="interlanguage-link interwiki-es mw-list-item"><a href="https://es.wikipedia.org/wiki/Classless_Inter-Domain_Routing" title="Classless Inter-Domain Routing – 西班牙语" lang="es" hreflang="es" data-title="Classless Inter-Domain Routing" data-language-autonym="Español" data-language-local-name="西班牙语" class="interlanguage-link-target"><span>Español</span></a></li><li class="interlanguage-link interwiki-fi mw-list-item"><a href="https://fi.wikipedia.org/wiki/Luokaton_reititys" title="Luokaton reititys – 芬兰语" lang="fi" hreflang="fi" data-title="Luokaton reititys" data-language-autonym="Suomi" data-language-local-name="芬兰语" class="interlanguage-link-target"><span>Suomi</span></a></li><li class="interlanguage-link interwiki-fr badge-Q70893996 mw-list-item" title=""><a href="https://fr.wikipedia.org/wiki/CIDR" title="CIDR – 法语" lang="fr" hreflang="fr" data-title="CIDR" data-language-autonym="Français" data-language-local-name="法语" class="interlanguage-link-target"><span>Français</span></a></li><li class="interlanguage-link interwiki-hr mw-list-item"><a href="https://hr.wikipedia.org/wiki/CIDR" title="CIDR – 克罗地亚语" lang="hr" hreflang="hr" data-title="CIDR" data-language-autonym="Hrvatski" data-language-local-name="克罗地亚语" class="interlanguage-link-target"><span>Hrvatski</span></a></li><li class="interlanguage-link interwiki-id mw-list-item"><a href="https://id.wikipedia.org/wiki/Classless_Inter-Domain_Routing" title="Classless Inter-Domain Routing – 印度尼西亚语" lang="id" hreflang="id" data-title="Classless Inter-Domain Routing" data-language-autonym="Bahasa Indonesia" data-language-local-name="印度尼西亚语" class="interlanguage-link-target"><span>Bahasa Indonesia</span></a></li><li class="interlanguage-link interwiki-it mw-list-item"><a href="https://it.wikipedia.org/wiki/Supernetting#CIDR" title="Supernetting – 意大利语" lang="it" hreflang="it" data-title="Supernetting" data-language-autonym="Italiano" data-language-local-name="意大利语" class="interlanguage-link-target"><span>Italiano</span></a></li><li class="interlanguage-link interwiki-ja mw-list-item"><a href="https://ja.wikipedia.org/wiki/Classless_Inter-Domain_Routing" title="Classless Inter-Domain Routing – 日语" lang="ja" hreflang="ja" data-title="Classless Inter-Domain Routing" data-language-autonym="日本語" data-language-local-name="日语" class="interlanguage-link-target"><span>日本語</span></a></li><li class="interlanguage-link interwiki-ko mw-list-item"><a href="https://ko.wikipedia.org/wiki/CIDR" title="CIDR – 韩语" lang="ko" hreflang="ko" data-title="CIDR" data-language-autonym="한국어" data-language-local-name="韩语" class="interlanguage-link-target"><span>한국어</span></a></li><li class="interlanguage-link interwiki-lv mw-list-item"><a href="https://lv.wikipedia.org/wiki/Bezklases_starpdom%C4%93nu_mar%C5%A1rut%C4%93%C5%A1ana" title="Bezklases starpdomēnu maršrutēšana – 拉脱维亚语" lang="lv" hreflang="lv" data-title="Bezklases starpdomēnu maršrutēšana" data-language-autonym="Latviešu" data-language-local-name="拉脱维亚语" class="interlanguage-link-target"><span>Latviešu</span></a></li><li class="interlanguage-link interwiki-mk mw-list-item"><a href="https://mk.wikipedia.org/wiki/CIDR" title="CIDR – 马其顿语" lang="mk" hreflang="mk" data-title="CIDR" data-language-autonym="Македонски" data-language-local-name="马其顿语" class="interlanguage-link-target"><span>Македонски</span></a></li><li class="interlanguage-link interwiki-nl mw-list-item"><a href="https://nl.wikipedia.org/wiki/Classless_Inter-Domain_Routing" title="Classless Inter-Domain Routing – 荷兰语" lang="nl" hreflang="nl" data-title="Classless Inter-Domain Routing" data-language-autonym="Nederlands" data-language-local-name="荷兰语" class="interlanguage-link-target"><span>Nederlands</span></a></li><li class="interlanguage-link interwiki-no mw-list-item"><a href="https://no.wikipedia.org/wiki/Classless_Inter-Domain_Routing" title="Classless Inter-Domain Routing – 书面挪威语" lang="nb" hreflang="nb" data-title="Classless Inter-Domain Routing" data-language-autonym="Norsk bokmål" data-language-local-name="书面挪威语" class="interlanguage-link-target"><span>Norsk bokmål</span></a></li><li class="interlanguage-link interwiki-pl mw-list-item"><a href="https://pl.wikipedia.org/wiki/Classless_Inter-Domain_Routing" title="Classless Inter-Domain Routing – 波兰语" lang="pl" hreflang="pl" data-title="Classless Inter-Domain Routing" data-language-autonym="Polski" data-language-local-name="波兰语" class="interlanguage-link-target"><span>Polski</span></a></li><li class="interlanguage-link interwiki-pt mw-list-item"><a href="https://pt.wikipedia.org/wiki/Roteamento_entre_dom%C3%ADnios_sem_classes" title="Roteamento entre domínios sem classes – 葡萄牙语" lang="pt" hreflang="pt" data-title="Roteamento entre domínios sem classes" data-language-autonym="Português" data-language-local-name="葡萄牙语" class="interlanguage-link-target"><span>Português</span></a></li><li class="interlanguage-link interwiki-ru mw-list-item"><a href="https://ru.wikipedia.org/wiki/%D0%91%D0%B5%D1%81%D0%BA%D0%BB%D0%B0%D1%81%D1%81%D0%BE%D0%B2%D0%B0%D1%8F_%D0%B0%D0%B4%D1%80%D0%B5%D1%81%D0%B0%D1%86%D0%B8%D1%8F" title="Бесклассовая адресация – 俄语" lang="ru" hreflang="ru" data-title="Бесклассовая адресация" data-language-autonym="Русский" data-language-local-name="俄语" class="interlanguage-link-target"><span>Русский</span></a></li><li class="interlanguage-link interwiki-simple mw-list-item"><a href="https://simple.wikipedia.org/wiki/Classless_Inter-Domain_Routing" title="Classless Inter-Domain Routing – Simple English" lang="en-simple" hreflang="en-simple" data-title="Classless Inter-Domain Routing" data-language-autonym="Simple English" data-language-local-name="Simple English" class="interlanguage-link-target"><span>Simple English</span></a></li><li class="interlanguage-link interwiki-sr mw-list-item"><a href="https://sr.wikipedia.org/wiki/CIDR" title="CIDR – 塞尔维亚语" lang="sr" hreflang="sr" data-title="CIDR" data-language-autonym="Српски / srpski" data-language-local-name="塞尔维亚语" class="interlanguage-link-target"><span>Српски / srpski</span></a></li><li class="interlanguage-link interwiki-sv mw-list-item"><a href="https://sv.wikipedia.org/wiki/Classless_Inter-Domain_Routing" title="Classless Inter-Domain Routing – 瑞典语" lang="sv" hreflang="sv" data-title="Classless Inter-Domain Routing" data-language-autonym="Svenska" data-language-local-name="瑞典语" class="interlanguage-link-target"><span>Svenska</span></a></li><li class="interlanguage-link interwiki-tr mw-list-item"><a href="https://tr.wikipedia.org/wiki/S%C4%B1n%C4%B1fs%C4%B1z_alanlar_aras%C4%B1_y%C3%B6nlendirme" title="Sınıfsız alanlar arası yönlendirme – 土耳其语" lang="tr" hreflang="tr" data-title="Sınıfsız alanlar arası yönlendirme" data-language-autonym="Türkçe" data-language-local-name="土耳其语" class="interlanguage-link-target"><span>Türkçe</span></a></li><li class="interlanguage-link interwiki-uk mw-list-item"><a href="https://uk.wikipedia.org/wiki/CIDR" title="CIDR – 乌克兰语" lang="uk" hreflang="uk" data-title="CIDR" data-language-autonym="Українська" data-language-local-name="乌克兰语" class="interlanguage-link-target"><span>Українська</span></a></li><li class="interlanguage-link interwiki-vi mw-list-item"><a href="https://vi.wikipedia.org/wiki/Classless_Inter-Domain_Routing" title="Classless Inter-Domain Routing – 越南语" lang="vi" hreflang="vi" data-title="Classless Inter-Domain Routing" data-language-autonym="Tiếng Việt" data-language-local-name="越南语" class="interlanguage-link-target"><span>Tiếng Việt</span></a></li> </ul> <div class="after-portlet after-portlet-lang"><span class="wb-langlinks-edit wb-langlinks-link"><a href="https://www.wikidata.org/wiki/Special:EntityPage/Q646589#sitelinks-wikipedia" title="编辑跨语言链接" class="wbc-editpage">编辑链接</a></span></div> </div> </div> </div> </header> <div class="vector-page-toolbar"> <div class="vector-page-toolbar-container"> <div id="left-navigation"> <nav aria-label="命名空间"> <div id="p-associated-pages" class="vector-menu vector-menu-tabs mw-portlet mw-portlet-associated-pages" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="ca-nstab-main" class="selected vector-tab-noicon mw-list-item"><a href="/wiki/%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1" title="浏览条目正文[c]" accesskey="c"><span>条目</span></a></li><li id="ca-talk" class="vector-tab-noicon mw-list-item"><a href="/wiki/Talk:%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1" rel="discussion" title="关于此页面的讨论[t]" accesskey="t"><span>讨论</span></a></li> </ul> </div> </div> <div id="vector-variants-dropdown" class="vector-dropdown " > <input type="checkbox" id="vector-variants-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-variants-dropdown" class="vector-dropdown-checkbox " aria-label="更改语言变体" > <label id="vector-variants-dropdown-label" for="vector-variants-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet" aria-hidden="true" ><span class="vector-dropdown-label-text">不转换</span> </label> <div class="vector-dropdown-content"> <div id="p-variants" class="vector-menu mw-portlet mw-portlet-variants" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="ca-varlang-0" class="selected ca-variants-zh mw-list-item"><a href="/zh/%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1" lang="zh" hreflang="zh"><span>不转换</span></a></li><li id="ca-varlang-1" class="ca-variants-zh-Hans mw-list-item"><a href="/zh-hans/%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1" lang="zh-Hans" hreflang="zh-Hans"><span>简体</span></a></li><li id="ca-varlang-2" class="ca-variants-zh-Hant mw-list-item"><a href="/zh-hant/%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1" lang="zh-Hant" hreflang="zh-Hant"><span>繁體</span></a></li><li id="ca-varlang-3" class="ca-variants-zh-Hans-CN mw-list-item"><a href="/zh-cn/%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1" lang="zh-Hans-CN" hreflang="zh-Hans-CN"><span>大陆简体</span></a></li><li id="ca-varlang-4" class="ca-variants-zh-Hant-HK mw-list-item"><a href="/zh-hk/%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1" lang="zh-Hant-HK" hreflang="zh-Hant-HK"><span>香港繁體</span></a></li><li id="ca-varlang-5" class="ca-variants-zh-Hant-MO mw-list-item"><a href="/zh-mo/%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1" lang="zh-Hant-MO" hreflang="zh-Hant-MO"><span>澳門繁體</span></a></li><li id="ca-varlang-6" class="ca-variants-zh-Hans-MY mw-list-item"><a href="/zh-my/%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1" lang="zh-Hans-MY" hreflang="zh-Hans-MY"><span>大马简体</span></a></li><li id="ca-varlang-7" class="ca-variants-zh-Hans-SG mw-list-item"><a href="/zh-sg/%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1" lang="zh-Hans-SG" hreflang="zh-Hans-SG"><span>新加坡简体</span></a></li><li id="ca-varlang-8" class="ca-variants-zh-Hant-TW mw-list-item"><a href="/zh-tw/%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1" lang="zh-Hant-TW" hreflang="zh-Hant-TW"><span>臺灣正體</span></a></li> </ul> </div> </div> </div> </div> </nav> </div> <div id="right-navigation" class="vector-collapsible"> <nav aria-label="查看"> <div id="p-views" class="vector-menu vector-menu-tabs mw-portlet mw-portlet-views" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="ca-view" class="selected vector-tab-noicon mw-list-item"><a href="/wiki/%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1"><span>阅读</span></a></li><li id="ca-edit" class="vector-tab-noicon mw-list-item"><a href="/w/index.php?title=%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1&action=edit" title="编辑该页面[e]" accesskey="e"><span>编辑</span></a></li><li id="ca-history" class="vector-tab-noicon mw-list-item"><a href="/w/index.php?title=%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1&action=history" title="本页面的早前版本。[h]" accesskey="h"><span>查看历史</span></a></li> </ul> </div> </div> </nav> <nav class="vector-page-tools-landmark" aria-label="页面工具"> <div id="vector-page-tools-dropdown" class="vector-dropdown vector-page-tools-dropdown" > <input type="checkbox" id="vector-page-tools-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-page-tools-dropdown" class="vector-dropdown-checkbox " aria-label="工具" > <label id="vector-page-tools-dropdown-label" for="vector-page-tools-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet" aria-hidden="true" ><span class="vector-dropdown-label-text">工具</span> </label> <div class="vector-dropdown-content"> <div id="vector-page-tools-unpinned-container" class="vector-unpinned-container"> <div id="vector-page-tools" class="vector-page-tools vector-pinnable-element"> <div class="vector-pinnable-header vector-page-tools-pinnable-header vector-pinnable-header-unpinned" data-feature-name="page-tools-pinned" data-pinnable-element-id="vector-page-tools" data-pinned-container-id="vector-page-tools-pinned-container" data-unpinned-container-id="vector-page-tools-unpinned-container" > <div class="vector-pinnable-header-label">工具</div> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-page-tools.pin">移至侧栏</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-page-tools.unpin">隐藏</button> </div> <div id="p-cactions" class="vector-menu mw-portlet mw-portlet-cactions emptyPortlet vector-has-collapsible-items" title="更多选项" > <div class="vector-menu-heading"> 操作 </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="ca-more-view" class="selected vector-more-collapsible-item mw-list-item"><a href="/wiki/%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1"><span>阅读</span></a></li><li id="ca-more-edit" class="vector-more-collapsible-item mw-list-item"><a href="/w/index.php?title=%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1&action=edit" title="编辑该页面[e]" accesskey="e"><span>编辑</span></a></li><li id="ca-more-history" class="vector-more-collapsible-item mw-list-item"><a href="/w/index.php?title=%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1&action=history"><span>查看历史</span></a></li> </ul> </div> </div> <div id="p-tb" class="vector-menu mw-portlet mw-portlet-tb" > <div class="vector-menu-heading"> 常规 </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="t-whatlinkshere" class="mw-list-item"><a href="/wiki/Special:%E9%93%BE%E5%85%A5%E9%A1%B5%E9%9D%A2/%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1" title="列出所有与本页相链的页面[j]" accesskey="j"><span>链入页面</span></a></li><li id="t-recentchangeslinked" class="mw-list-item"><a href="/wiki/Special:%E9%93%BE%E5%87%BA%E6%9B%B4%E6%94%B9/%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1" rel="nofollow" title="页面链出所有页面的更改[k]" accesskey="k"><span>相关更改</span></a></li><li id="t-upload" class="mw-list-item"><a href="/wiki/Project:%E4%B8%8A%E4%BC%A0" title="上传图像或多媒体文件[u]" accesskey="u"><span>上传文件</span></a></li><li id="t-specialpages" class="mw-list-item"><a href="/wiki/Special:%E7%89%B9%E6%AE%8A%E9%A1%B5%E9%9D%A2" title="全部特殊页面的列表[q]" accesskey="q"><span>特殊页面</span></a></li><li id="t-permalink" class="mw-list-item"><a href="/w/index.php?title=%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1&oldid=79295521" title="此页面该修订版本的固定链接"><span>固定链接</span></a></li><li id="t-info" class="mw-list-item"><a href="/w/index.php?title=%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1&action=info" title="关于此页面的更多信息"><span>页面信息</span></a></li><li id="t-cite" class="mw-list-item"><a href="/w/index.php?title=Special:%E5%BC%95%E7%94%A8%E6%AD%A4%E9%A1%B5%E9%9D%A2&page=%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1&id=79295521&wpFormIdentifier=titleform" title="有关如何引用此页面的信息"><span>引用此页</span></a></li><li id="t-urlshortener" class="mw-list-item"><a href="/w/index.php?title=Special:URL%E7%BC%A9%E7%9F%AD%E7%A8%8B%E5%BA%8F&url=https%3A%2F%2Fzh.wikipedia.org%2Fwiki%2F%25E6%2597%25A0%25E7%25B1%25BB%25E5%2588%25AB%25E5%259F%259F%25E9%2597%25B4%25E8%25B7%25AF%25E7%2594%25B1"><span>获取短链接</span></a></li><li id="t-urlshortener-qrcode" class="mw-list-item"><a href="/w/index.php?title=Special:QrCode&url=https%3A%2F%2Fzh.wikipedia.org%2Fwiki%2F%25E6%2597%25A0%25E7%25B1%25BB%25E5%2588%25AB%25E5%259F%259F%25E9%2597%25B4%25E8%25B7%25AF%25E7%2594%25B1"><span>下载二维码</span></a></li> </ul> </div> </div> <div id="p-electronpdfservice-sidebar-portlet-heading" class="vector-menu mw-portlet mw-portlet-electronpdfservice-sidebar-portlet-heading" > <div class="vector-menu-heading"> 打印/导出 </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="electron-print_pdf" class="mw-list-item"><a href="/w/index.php?title=Special:DownloadAsPdf&page=%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1&action=show-download-screen"><span>下载为PDF</span></a></li><li id="t-print" class="mw-list-item"><a href="javascript:print();" rel="alternate" title="本页面的可打印版本[p]" accesskey="p"><span>打印页面</span></a></li> </ul> </div> </div> <div id="p-wikibase-otherprojects" class="vector-menu mw-portlet mw-portlet-wikibase-otherprojects" > <div class="vector-menu-heading"> 在其他项目中 </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li class="wb-otherproject-link wb-otherproject-commons mw-list-item"><a href="https://commons.wikimedia.org/wiki/Category:CIDR" hreflang="en"><span>维基共享资源</span></a></li><li id="t-wikibase" class="wb-otherproject-link wb-otherproject-wikibase-dataitem mw-list-item"><a href="https://www.wikidata.org/wiki/Special:EntityPage/Q646589" title="链接到连接的数据仓库项目[g]" accesskey="g"><span>维基数据项目</span></a></li> </ul> </div> </div> </div> </div> </div> </div> </nav> </div> </div> </div> <div class="vector-column-end"> <div class="vector-sticky-pinned-container"> <nav class="vector-page-tools-landmark" aria-label="页面工具"> <div id="vector-page-tools-pinned-container" class="vector-pinned-container"> </div> </nav> <nav class="vector-appearance-landmark" aria-label="外观"> <div id="vector-appearance-pinned-container" class="vector-pinned-container"> <div id="vector-appearance" class="vector-appearance vector-pinnable-element"> <div class="vector-pinnable-header vector-appearance-pinnable-header vector-pinnable-header-pinned" data-feature-name="appearance-pinned" data-pinnable-element-id="vector-appearance" data-pinned-container-id="vector-appearance-pinned-container" data-unpinned-container-id="vector-appearance-unpinned-container" > <div class="vector-pinnable-header-label">外观</div> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-appearance.pin">移至侧栏</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-appearance.unpin">隐藏</button> </div> </div> </div> </nav> </div> </div> <div id="bodyContent" class="vector-body" aria-labelledby="firstHeading" data-mw-ve-target-container> <div class="vector-body-before-content"> <div class="mw-indicators"> <div id="mw-indicator-noteTA-f3e2a619" class="mw-indicator"><div class="mw-parser-output"><span class="skin-invert" typeof="mw:File"><span title="本页使用了标题或全文手工转换"><img alt="本页使用了标题或全文手工转换" src="//upload.wikimedia.org/wikipedia/commons/thumb/c/cd/Zh_conversion_icon_m.svg/35px-Zh_conversion_icon_m.svg.png" decoding="async" width="35" height="22" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/c/cd/Zh_conversion_icon_m.svg/53px-Zh_conversion_icon_m.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/c/cd/Zh_conversion_icon_m.svg/70px-Zh_conversion_icon_m.svg.png 2x" data-file-width="32" data-file-height="20" /></span></span></div></div> </div> <div id="siteSub" class="noprint">维基百科，自由的百科全书</div> </div> <div id="contentSub"><div id="mw-content-subtitle"></div></div> <div id="mw-content-text" class="mw-body-content"><div class="mw-content-ltr mw-parser-output" lang="zh" dir="ltr"><style data-mw-deduplicate="TemplateStyles:r84596247">.mw-parser-output .multiple-issues-text{width:95%;margin:0.2em 0}.mw-parser-output .multiple-issues-text>.mw-collapsible-content{margin-top:0.3em}.mw-parser-output .compact-ambox .ambox{border:none;border-collapse:collapse;background-color:transparent;margin:0 0 0 1.6em!important;padding:0!important;width:auto;display:block}body.mediawiki .mw-parser-output .compact-ambox .ambox.mbox-small-left{font-size:100%;width:auto;margin:0}.mw-parser-output .compact-ambox .ambox .mbox-text{padding:0!important;margin:0!important}.mw-parser-output .compact-ambox .ambox .mbox-text-span{display:list-item;line-height:1.5em;list-style-type:disc}body.skin-minerva .mw-parser-output .multiple-issues-text>.mw-collapsible-toggle,.mw-parser-output .compact-ambox .ambox .mbox-image,.mw-parser-output .compact-ambox .ambox .mbox-imageright,.mw-parser-output .compact-ambox .ambox .mbox-empty-cell{display:none}</style><style data-mw-deduplicate="TemplateStyles:r83732972">.mw-parser-output .ambox{border:1px solid #a2a9b1;border-left:10px solid #36c;background-color:#fbfbfb;box-sizing:border-box}.mw-parser-output .ambox+link+.ambox,.mw-parser-output .ambox+link+style+.ambox,.mw-parser-output .ambox+link+link+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+style+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+link+.ambox{margin-top:-1px}html body.mediawiki .mw-parser-output .ambox.mbox-small-left{margin:4px 1em 4px 0;overflow:hidden;width:238px;border-collapse:collapse;font-size:88%;line-height:1.25em}.mw-parser-output .ambox-speedy{border-left:10px solid #b32424;background-color:#fee7e6}.mw-parser-output .ambox-delete{border-left:10px solid #b32424}.mw-parser-output .ambox-content{border-left:10px solid #f28500}.mw-parser-output .ambox-style{border-left:10px solid #fc3}.mw-parser-output .ambox-move{border-left:10px solid #9932cc}.mw-parser-output .ambox-protection{border-left:10px solid #a2a9b1}.mw-parser-output .ambox .mbox-text{border:none;padding:0.25em 0.5em;width:100%}.mw-parser-output .ambox .mbox-image{border:none;padding:2px 0 2px 0.5em;text-align:center}.mw-parser-output .ambox .mbox-imageright{border:none;padding:2px 0.5em 2px 0;text-align:center}.mw-parser-output .ambox .mbox-empty-cell{border:none;padding:0;width:1px}.mw-parser-output .ambox .mbox-image-div{width:52px}html.client-js body.skin-minerva .mw-parser-output .mbox-text-span{margin-left:23px!important}@media(min-width:720px){.mw-parser-output .ambox{margin:0 10%}}@media screen{html.skin-theme-clientpref-night .mw-parser-output .ambox{border-left-color:#36c!important}html.skin-theme-clientpref-night .mw-parser-output .ambox-speedy,html.skin-theme-clientpref-night .mw-parser-output .ambox-delete{border-left-color:#b32424!important}html.skin-theme-clientpref-night .mw-parser-output .ambox-speedy{background-color:#300!important}html.skin-theme-clientpref-night .mw-parser-output .ambox-content{border-left-color:#f28500!important}html.skin-theme-clientpref-night .mw-parser-output .ambox-style{border-left-color:#fc3!important}html.skin-theme-clientpref-night .mw-parser-output .ambox-move{border-left-color:#9932cc!important}html.skin-theme-clientpref-night .mw-parser-output .ambox-protection{border-left-color:#a2a9b1!important}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .ambox{border-left-color:#36c!important}html.skin-theme-clientpref-os .mw-parser-output .ambox-speedy,html.skin-theme-clientpref-os .mw-parser-output .ambox-delete{border-left-color:#b32424!important}html.skin-theme-clientpref-os .mw-parser-output .ambox-speedy{background-color:#300!important}html.skin-theme-clientpref-os .mw-parser-output .ambox-content{border-left-color:#f28500!important}html.skin-theme-clientpref-os .mw-parser-output .ambox-style{border-left-color:#fc3!important}html.skin-theme-clientpref-os .mw-parser-output .ambox-move{border-left-color:#9932cc!important}html.skin-theme-clientpref-os .mw-parser-output .ambox-protection{border-left-color:#a2a9b1!important}}</style><table class="box-问题条目 plainlinks metadata ambox ambox-content ambox-multiple_issues compact-ambox" role="presentation"><tbody><tr><td class="mbox-image"><div style="width:52px"><span typeof="mw:File"><span><img alt="" src="//upload.wikimedia.org/wikipedia/commons/thumb/b/b4/Ambox_important.svg/40px-Ambox_important.svg.png" decoding="async" width="40" height="40" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/b/b4/Ambox_important.svg/60px-Ambox_important.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/b/b4/Ambox_important.svg/80px-Ambox_important.svg.png 2x" data-file-width="40" data-file-height="40" /></span></span></div></td><td class="mbox-text"><div class="mbox-text-span"><div class="multiple-issues-text mw-collapsible"><b>本條目存在以下問題</b>，請協助<b><a class="external text" href="https://zh.wikipedia.org/w/index.php?title=%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1&action=edit">改善本條目</a></b>或在<b><a href="/wiki/Talk:%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1" title="Talk:无类别域间路由">討論頁</a></b>針對議題發表看法。 <div class="mw-collapsible-content"> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r83732972"><table class="box-Expand_language plainlinks metadata ambox ambox-notice" role="presentation"><tbody><tr><td class="mbox-image"><div style="width:52px"><span class="skin-invert" typeof="mw:File"><span><img alt="" src="//upload.wikimedia.org/wikipedia/commons/thumb/d/da/Translation_to_zh_arrow.svg/50px-Translation_to_zh_arrow.svg.png" decoding="async" width="50" height="17" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/d/da/Translation_to_zh_arrow.svg/75px-Translation_to_zh_arrow.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/d/da/Translation_to_zh_arrow.svg/100px-Translation_to_zh_arrow.svg.png 2x" data-file-width="60" data-file-height="20" /></span></span></div></td><td class="mbox-text"><div class="mbox-text-span">此條目<b>可参照外語維基百科相應條目来扩充</b>。<span class="hide-when-compact"></span> <small class="date-container"><i>(<span class="date">2018年8月13日</span>)</i></small><span class="hide-when-compact"><br /><small>若您熟悉来源语言和主题，请协助<a href="/wiki/Wikipedia:%E7%BF%BB%E8%AF%91%E5%AE%88%E5%88%99" class="mw-redirect" title="Wikipedia:翻译守则">参考外语维基百科扩充条目</a>。请勿直接提交机械翻译，也不要翻译不可靠、低品质内容。依<a href="/wiki/Wikipedia:%E5%9C%A8%E7%BB%B4%E5%9F%BA%E7%99%BE%E7%A7%91%E5%86%85%E5%A4%8D%E5%88%B6%E5%86%85%E5%AE%B9" title="Wikipedia:在维基百科内复制内容">版权协议</a>，译文需<a href="/wiki/Wikipedia:%E7%B7%A8%E8%BC%AF%E6%91%98%E8%A6%81#翻譯文章" title="Wikipedia:編輯摘要">在编辑摘要注明来源</a>，或于讨论页顶部标记<code>{{<a href="/wiki/Template:Translated_page" title="Template:Translated page">Translated page</a>}}</code>标签。</small></span><span class="hide-when-compact"></span></div></td></tr></tbody></table> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r83732972"><table class="box-Update plainlinks metadata ambox ambox-content" role="presentation"><tbody><tr><td class="mbox-image"><div style="width:52px"><span typeof="mw:File"><span><img src="//upload.wikimedia.org/wikipedia/commons/thumb/8/8f/Ambox_outdated_serious.svg/40px-Ambox_outdated_serious.svg.png" decoding="async" width="40" height="40" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/8/8f/Ambox_outdated_serious.svg/60px-Ambox_outdated_serious.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/8/8f/Ambox_outdated_serious.svg/80px-Ambox_outdated_serious.svg.png 2x" data-file-width="620" data-file-height="620" /></span></span></div></td><td class="mbox-text"><div class="mbox-text-span">此條目<b>需要更新</b>。<span class="hide-when-compact"></span> <small class="date-container"><i>(<span class="date">2018年8月13日</span>)</i></small><span class="hide-when-compact"><br /><small>請更新本文以反映近況和新增内容。完成修改後請移除本模板。</small></span><span class="hide-when-compact"></span></div></td></tr></tbody></table> </div></div><span class="hide-when-compact"></span><span class="hide-when-compact"></span></div></td></tr></tbody></table> <div id="noteTA-f3e2a619" class="noteTA"><div class="noteTA-group"><div data-noteta-group-source="module" data-noteta-group="IT"></div></div></div> <p><b>无类别域间路由</b>（英語：<span lang="en">Classless Inter-Domain Routing</span>，簡稱<b>CIDR</b><span class="nowrap"><span class="IPA nopopups" lang="en-fonipa"><a href="/wiki/Help:%E8%8B%B1%E8%AA%9E%E5%9C%8B%E9%9A%9B%E9%9F%B3%E6%A8%99" title="Help:英語國際音標">/<span style="border-bottom:1px dotted"><span title="/ˈ/：後面為主重音">ˈ</span><span title="「sigh」的「s」音">s</span><span title="/aɪ/：「tide」的「i」音">aɪ</span><span title="「dye」的「d」音">d</span><span title="/ər/：「letter」的「er」音">ər</span></span>,<span class="wrap"> </span><span style="border-bottom:1px dotted"><span title="/ˈ/：後面為主重音">ˈ</span><span title="「sigh」的「s」音">s</span><span title="/ɪ/：「kit」的「i」音">ɪ</span></span>-/</a></span></span>）是一个用于给用户分配<a href="/wiki/IP%E5%9C%B0%E5%9D%80" title="IP地址">IP地址</a>以及在<a href="/wiki/%E4%BA%92%E8%81%94%E7%BD%91" title="互联网">互联网</a>上有效地路由IP<a href="/wiki/%E6%95%B0%E6%8D%AE%E5%8C%85" class="mw-redirect" title="数据包">数据包</a>的对IP地址进行归类的方法。 </p><p>在<a href="/wiki/%E5%9F%9F%E5%90%8D%E7%B3%BB%E7%BB%9F" title="域名系统">域名系统</a>出现之后的第一个十年里，基于<a href="/wiki/%E5%88%86%E7%B1%BB%E7%BD%91%E7%BB%9C" title="分类网络">分类网络</a>进行地址分配和路由IP数据包的设计就已明显显得<a href="/wiki/%E5%8F%AF%E6%89%A9%E6%94%BE%E6%80%A7" class="mw-redirect" title="可扩放性">可扩充性</a>不足（参见RFC 1517）。为了解决这个问题，<a href="/wiki/%E4%BA%92%E8%81%94%E7%BD%91%E5%B7%A5%E7%A8%8B%E5%B7%A5%E4%BD%9C%E5%B0%8F%E7%BB%84" class="mw-redirect" title="互联网工程工作小组">互联网工程工作小组</a>在1993年发布了一新系列的标准——<a class="external mw-magiclink-rfc" rel="nofollow" href="https://tools.ietf.org/html/rfc1518">RFC 1518</a>和RFC 1519——以定义新的分配IP地址块和路由<a href="/wiki/IPv4" title="IPv4">IPv4</a>数据包的方法。<sup id="cite_ref-RFC_1518_1-0" class="reference"><a href="#cite_note-RFC_1518-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-RFC_1519_2-0" class="reference"><a href="#cite_note-RFC_1519-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup> </p><p>一个IP地址包含两部分：标识网络的<b>前缀</b>和紧接着的在这个网络内的<b>主机地址</b>。在之前的<a href="/wiki/%E5%88%86%E7%B1%BB%E7%BD%91%E7%BB%9C" title="分类网络">分类网络</a>中，IP地址的分配把IP地址的32位按每8位为一段分开。这使得前缀必须为8，16或者24位。因此，可分配的最小的地址块有256（24位前缀，8位主机地址，2<sup>8</sup>=256）个地址，而这对大多数企业来说太少了。大一点的地址块包含65536（16位前缀，16位主机，2<sup>16</sup>=65536）个地址，而这对大公司来说都太多了。这导致不能充分使用IP地址和在路由上的不便，因为大量的需要单独路由的小型网络（C类网络）因在地域上分得很开而很难进行<a href="/w/index.php?title=%E8%81%9A%E5%90%88%E8%B7%AF%E7%94%B1&action=edit&redlink=1" class="new" title="聚合路由（页面不存在）">聚合路由</a>，于是给路由设备增加了很多负担。 </p><p>无类别域间路由是基于<b>可变长子网掩码（VLSM）</b>来进行任意长度的前缀的分配的。在RFC 950（1985）中有关于可变长子网掩码的说明。CIDR包括： </p> <ul><li>指定任意长度的前缀的可变长子网掩码技术。遵从CIDR规则的地址有一个后缀说明前缀的位数，例如：192.168.0.0/16。这使得对日益缺乏的IPv4地址的使用更加有效。</li> <li>将多个连续的前缀聚合成<b><a href="/w/index.php?title=%E8%B6%85%E7%BD%91&action=edit&redlink=1" class="new" title="超网（页面不存在）">超网</a></b>，以及，在互联网中，只要有可能，就显示为一个聚合的网络，因此在总体上可以减少路由表的表项数目。聚合使得互联网的路由表不用分为多级，并通过VLSM逆转“划分子网”的过程。</li> <li>根据机构的实际需要和短期预期需要而不是分类网络中所限定的过大或过小的地址块来管理IP地址的分配的过程。</li></ul> <p>因为在<a href="/wiki/IPv6" title="IPv6">IPv6</a>中也使用了IPv4的用后缀指示前缀长度的CIDR，所以IPv4中的<i>分类</i>在IPv6中已不再使用。 </p> <meta property="mw:PageProp/toc" /> <div class="mw-heading mw-heading2"><h2 id="CIDR块"><span id="CIDR.E5.9D.97"></span>CIDR块</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1&action=edit&section=1" title="编辑章节：CIDR块"><span>编辑</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-halign-left" typeof="mw:File/Thumb"><a href="/wiki/File:IP_Address_Match.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/7/7b/IP_Address_Match.svg/400px-IP_Address_Match.svg.png" decoding="async" width="400" height="394" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/7/7b/IP_Address_Match.svg/600px-IP_Address_Match.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/7/7b/IP_Address_Match.svg/800px-IP_Address_Match.svg.png 2x" data-file-width="621" data-file-height="612" /></a><figcaption>如果我们指定一个CIDR块为10.10.1.32/27，则根据CIDR比特位比较，10.10.1.44是属于该块，但10.10.1.90则不是。</figcaption></figure> <p>CIDR主要是一个按位的、基于前缀的，用于解释IP地址的标准。它通过把多个地址块组合到一个<a href="/wiki/%E8%B7%AF%E7%94%B1%E8%A1%A8" title="路由表">路由表</a>表项而使得<a href="/wiki/%E8%B7%AF%E7%94%B1" title="路由">路由</a>更加方便。这些地址块叫做<b>CIDR地址块</b>、<b>CIDR块</b>、<b>CIDR区块</b>或<b>IP段</b>。当用<a href="/wiki/%E4%BA%8C%E8%BF%9B%E5%88%B6" title="二进制">二进制</a>表示这些地址时，它们有着在开头部分的一系列相同的位。IPv4的CIDR地址块的表示方法和IPv4地址的表示方法是相似的：由四部分组成的点分十进制地址，后跟一个斜线，最后是范围在0到32之间的一个数字：<i>A.B.C.D/N</i>。点分十进制的部分和IPv4地址一样是一个被分成四个八位位组的32位二进制数。斜線后面的数字就是<b>前缀长度</b>，也就是从左到右，被地址块里的地址所共享的位的数目。当只需说明大概时，十进制部分有时会被省略，因此，<i>/20</i>就表示一个前缀长度是20的CIDR地址块。如果一个IP地址的前N位与一个CIDR地址块的前缀是相同的话，那么就说这个地址属于这个CIDR地址块，也可以说是与CIDR地址块的前缀匹配。所以，要理解CIDR，就要把地址写成<a href="/wiki/%E4%BA%8C%E8%BF%9B%E5%88%B6" title="二进制">二进制</a>的形式。因为IPv4地址的长度总是32位，N位长的CIDR前缀就意味着地址里前N位匹配，后<span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle 32-N}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mn>32</mn> <mo>−</mo> <mi>N</mi> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle 32-N}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/973650ff68b568346050d7bde8f5e8e64ce7e0ab" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.505ex; width:7.229ex; height:2.343ex;" alt="{\displaystyle 32-N}"></span>位不匹配。这些位有<span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle 2^{(32-N)}}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <msup> <mn>2</mn> <mrow class="MJX-TeXAtom-ORD"> <mo stretchy="false">(</mo> <mn>32</mn> <mo>−</mo> <mi>N</mi> <mo stretchy="false">)</mo> </mrow> </msup> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle 2^{(32-N)}}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/539a70c0eef9a8306f03e20514d61af20ca11693" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:7.056ex; height:2.843ex;" alt="{\displaystyle 2^{(32-N)}}"></span>种不同的组合，即<span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle 2^{(32-N)}}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <msup> <mn>2</mn> <mrow class="MJX-TeXAtom-ORD"> <mo stretchy="false">(</mo> <mn>32</mn> <mo>−</mo> <mi>N</mi> <mo stretchy="false">)</mo> </mrow> </msup> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle 2^{(32-N)}}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/539a70c0eef9a8306f03e20514d61af20ca11693" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:7.056ex; height:2.843ex;" alt="{\displaystyle 2^{(32-N)}}"></span>个IPv4地址与CIDR地址块的前缀匹配。前缀越短就能匹配越多的地址，越长就匹配得越少。一个地址可能与多个长度不同的CIDR前缀匹配。CIDR也用在<a href="/wiki/IPv6" title="IPv6">IPv6</a>中。因为位数的非常多，所以在IPv6中，前缀长度的范围是从0到128。这里也用同样的方法来表示一个地址：前缀写作一个IPv6的地址，後跟一个斜線，最后是前缀的位数。 </p> <div style="clear:both;"></div> <div class="mw-heading mw-heading2"><h2 id="CIDR块的分配"><span id="CIDR.E5.9D.97.E7.9A.84.E5.88.86.E9.85.8D"></span>CIDR块的分配</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1&action=edit&section=2" title="编辑章节：CIDR块的分配"><span>编辑</span></a><span class="mw-editsection-bracket">]</span></span></div> <p><a href="/wiki/%E4%BA%92%E8%81%94%E7%BD%91%E5%9C%B0%E5%9D%80%E6%8C%87%E6%B4%BE%E6%9C%BA%E6%9E%84" class="mw-redirect" title="互联网地址指派机构">互联网地址指派机构</a>（IANA）向<a href="/wiki/%E5%8C%BA%E5%9F%9F%E4%BA%92%E8%81%94%E7%BD%91%E6%B3%A8%E5%86%8C%E7%AE%A1%E7%90%86%E6%9C%BA%E6%9E%84" title="区域互联网注册管理机构">区域互联网注册管理机构</a>（RIRs）分配数量多，前缀短的CIDR地址块。例如，包含有一千六百多万个地址的<i><span class="ip地址"><span style="padding-right: 1px;">62.0.0.0/8</span></span></i>地址块由<a href="/wiki/%E6%AC%A7%E6%B4%B2IP%E7%BD%91%E7%BB%9C%E8%B5%84%E6%BA%90%E5%8D%8F%E8%B0%83%E4%B8%AD%E5%BF%83" title="欧洲IP网络资源协调中心">RIPE NCC</a>（欧洲的RIR）管理。这些RIR各自负责管理一个单一区域（例如欧洲或者北美），然后它们把这些地址块分成小一些的地址块再分配给公众。这个细分的操作可能会由不同层次的团体进行多次。大型<a href="/wiki/%E4%BA%92%E8%81%94%E7%BD%91%E6%9C%8D%E5%8A%A1%E4%BE%9B%E5%BA%94%E5%95%86" title="互联网服务供应商">网络服务供应商</a>（<a href="/wiki/%E4%BA%92%E8%81%94%E7%BD%91%E6%9C%8D%E5%8A%A1%E4%BE%9B%E5%BA%94%E5%95%86" title="互联网服务供应商">ISP</a>）一般会从RIR申请CIDR地址块，然后再向根据它们客户的网络大小而分配更小的地址块。<a href="/wiki/%E4%BA%92%E8%81%94%E7%BD%91%E5%B7%A5%E7%A8%8B%E5%B7%A5%E4%BD%9C%E5%B0%8F%E7%BB%84" class="mw-redirect" title="互联网工程工作小组">互联网工程工作小组</a>鼓励由单一ISP服务的网络直接向ISP申请地址。而由多个ISP提供服务的，则经常会向适当的RIR申请<a href="/wiki/PI%E5%9C%B0%E5%9D%80%E7%A9%BA%E9%97%B4" class="mw-redirect" title="PI地址空间">独立的</a>CIDR地址块。 </p> <figure class="mw-halign-right" typeof="mw:File/Thumb"><a href="/wiki/File:CIDR_Address.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/2/26/CIDR_Address.svg/400px-CIDR_Address.svg.png" decoding="async" width="400" height="220" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/2/26/CIDR_Address.svg/600px-CIDR_Address.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/2/26/CIDR_Address.svg/800px-CIDR_Address.svg.png 2x" data-file-width="800" data-file-height="440" /></a><figcaption>借助超网聚合和前缀子网划分机制，我们可以通过<span class="ilh-all" data-orig-title="MCI通信" data-lang-code="en" data-lang-name="英语" data-foreign-title="MCI Communications"><span class="ilh-page"><a href="/w/index.php?title=MCI%E9%80%9A%E4%BF%A1&action=edit&redlink=1" class="new" title="MCI通信（页面不存在）">MCI通信</a></span><span class="noprint ilh-comment">（<span class="ilh-lang">英语</span><span class="ilh-colon">：</span><span class="ilh-link"><a href="https://en.wikipedia.org/wiki/MCI_Communications" class="extiw" title="en:MCI Communications"><span lang="en" dir="auto">MCI Communications</span></a></span>）</span></span>的子网块，找到Automation Research Systems的子网块，进而找到Automation Research Systems的公共主机子网块，进而找到freesoft.org的web网页主机，同样地，互联网路由系统也是根据这个子网归属来将IP包路由到主机处。</figcaption></figure> <p>例如，在90年代末，IP地址<i><span class="ip地址"><span style="padding-right: 1px;">208.130.29.33</span></span></i>是被<a rel="nofollow" class="external text" href="http://www.freesoft.org/">www.freesoft.org</a> （<a rel="nofollow" class="external text" href="//web.archive.org/web/20190524034229/http://www.freesoft.org/">页面存档备份</a>，存于<a href="/wiki/%E4%BA%92%E8%81%94%E7%BD%91%E6%A1%A3%E6%A1%88%E9%A6%86" title="互联网档案馆">互联网档案馆</a>）使用的。后来，分配发生了变化。<i><span class="ip地址"><span style="padding-right: 1px;">208.128.0.0/11</span></span></i>，这个包含两百万地址的块被<a href="/wiki/ARIN" class="mw-redirect" title="ARIN">ARIN</a>（北美的RIR）分配给了<span class="ilh-all" data-orig-title="MCI通信" data-lang-code="en" data-lang-name="英语" data-foreign-title="MCI Communications"><span class="ilh-page"><a href="/w/index.php?title=MCI%E9%80%9A%E4%BF%A1&action=edit&redlink=1" class="new" title="MCI通信（页面不存在）">MCI通信</a></span><span class="noprint ilh-comment">（<span class="ilh-lang">英语</span><span class="ilh-colon">：</span><span class="ilh-link"><a href="https://en.wikipedia.org/wiki/MCI_Communications" class="extiw" title="en:MCI Communications"><span lang="en" dir="auto">MCI Communications</span></a></span>）</span></span>。MCI又将<i><span class="ip地址"><span style="padding-right: 1px;">208.130.28.0/22</span></span></i>分配给了从MCI租用互联网连接的Automation Research Systems。ARS则用了<i><span class="ip地址"><span style="padding-right: 1px;">208.130.29.0/24</span></span></i>这个地址块，其中就包含<i><span class="ip地址"><span style="padding-right: 1px;">208.130.29.33</span></span></i>这个地址。这些CIDR前缀会在不同的地方使用。在MCI的网络之外，<i><span class="ip地址"><span style="padding-right: 1px;">208.128.0.0/11</span></span></i>这个前缀会用于路由MCI的数据流。这些数据流不仅会去到<i><span class="ip地址"><span style="padding-right: 1px;">208.130.29.33</span></span></i>，也会去到其他那些前11位相同的近两百万的地址里。在MCI的网络里，<i><span class="ip地址"><span style="padding-right: 1px;">208.130.28.0/22</span></span></i>则会被用于路由到属于ARS租用的连接。最后，只有在ARS自己的网络内<i><span class="ip地址"><span style="padding-right: 1px;">208.130.29.0/24</span></span></i>这个前缀才会被使用。 </p> <div style="clear:both;"></div> <div class="mw-heading mw-heading2"><h2 id="CIDR和掩码"><span id="CIDR.E5.92.8C.E6.8E.A9.E7.A0.81"></span>CIDR和掩码</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1&action=edit&section=3" title="编辑章节：CIDR和掩码"><span>编辑</span></a><span class="mw-editsection-bracket">]</span></span></div> <p><a href="/wiki/%E5%AD%90%E7%BD%91%E6%8E%A9%E7%A0%81" class="mw-redirect" title="子网掩码">子网掩码</a>是一种把前缀编成一种与IP地址相似的形式的掩码。一个子网掩码一共有32位，被分为连续的两部分，高位部分的每一位都被设为二进制的1，其余部分的每一位均被设为二进制的0。其中为1的位的数目和前缀的长度相同。它也被写成点分十进制的形式。子网掩码的作用和前缀一样，但是掩码这种形式出现得比前缀要早。 </p><p>CIDR用<b>可变长子网掩码</b>（<b>VLSM</b>，Variable Length Subnet Masking），根据各人需要来分配IP地址，而不是按照一个全网络约定的规则。所以，网络/主机的划分可以在地址内的任意位置进行。这个划分可以是<a href="/wiki/%E9%80%92%E5%BD%92" title="递归">递归</a>进行的，即通过增加掩码位数，来使一部分地址被继续分为更小的部分。整个互联网现在都在使用CIDR/VLSM网络地址。除此之外，CIDR也应用在其他方面，尤其是大型私人网络。<style data-mw-deduplicate="TemplateStyles:r83946278">.mw-parser-output .template-facttext{background-color:var(--background-color-neutral,#eaecf0);color:inherit;margin:-.3em 0;padding:.3em 0}</style><mark class="template-facttext" title="需要提供文献来源">在普通大小的<a href="/wiki/%E5%B1%80%E5%9F%9F%E7%BD%91" title="局域网">局域网</a>里则较少应用，因为这些局域网一般使用<a href="/wiki/%E7%A7%81%E6%9C%89%E7%BD%91%E7%BB%9C" class="mw-redirect" title="私有网络">私有网络</a>。</mark><sup class="noprint Template-Fact"><a href="/wiki/Wikipedia:%E5%88%97%E6%98%8E%E6%9D%A5%E6%BA%90" title="Wikipedia:列明来源"><span style="white-space: nowrap;" title="来源请求开始于2013年2月1日。">[來源請求]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="前缀聚合"><span id=".E5.89.8D.E7.BC.80.E8.81.9A.E5.90.88"></span>前缀聚合</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1&action=edit&section=4" title="编辑章节：前缀聚合"><span>编辑</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>CIDR的另一个好处就是可以进行<b>前缀路由聚合</b>。例如，16个原来的C类（/24）网络现在可以聚合在一起，对外显示了一个/20的网络了（如果这些网络的的地址前20位都相同）。两个对齐的/20网络又可进一步聚合为/19，依此类推。这有效地减少了要对外显示的网络数，防止了路由表爆炸，也遏制了互联网进一步扩大。 </p> <table class="wikitable"> <caption>CIDR </caption> <tbody><tr> <th>IP/CIDR </th> <th>Δ 与最后一个地址的差值 </th> <th>掩码 </th> <th>主机数 (*) </th> <th>类别 </th> <th>备注 </th></tr> <tr> <td>a.b.c.d<b>/32</b> </td> <td>+0.0.0.0 </td> <td>255.255.255.255 </td> <td>1 </td> <td>1/256 C </td> <td> </td></tr> <tr> <td>a.b.c.d<b>/31</b> </td> <td>+0.0.0.1 </td> <td>255.255.255.254 </td> <td>2 </td> <td>1/128 C </td> <td>d = 0 ... (2n) ... 254 </td></tr> <tr> <td>a.b.c.d<b>/30</b> </td> <td>+0.0.0.3 </td> <td>255.255.255.252 </td> <td>4 </td> <td>1/64 C </td> <td>d = 0 ... (4n) ... 252 </td></tr> <tr> <td>a.b.c.d<b>/29</b> </td> <td>+0.0.0.7 </td> <td>255.255.255.248 </td> <td>8 </td> <td>1/32 C </td> <td>d = 0 ... (8n) ... 248 </td></tr> <tr> <td>a.b.c.d<b>/28</b> </td> <td>+0.0.0.15 </td> <td>255.255.255.240 </td> <td>16 </td> <td>1/16 C </td> <td>d = 0 ... (16n) ... 240 </td></tr> <tr> <td>a.b.c.d<b>/27</b> </td> <td>+0.0.0.31 </td> <td>255.255.255.224 </td> <td>32 </td> <td>1/8 C </td> <td>d = 0 ... (32n) ... 224 </td></tr> <tr> <td>a.b.c.d<b>/26</b> </td> <td>+0.0.0.63 </td> <td>255.255.255.192 </td> <td>64 </td> <td>1/4 C </td> <td>d = 0, 64, 128, 192 </td></tr> <tr> <td>a.b.c.d<b>/25</b> </td> <td>+0.0.0.127 </td> <td>255.255.255.128 </td> <td>128 </td> <td>1/2 C </td> <td>d = 0, 128 </td></tr> <tr> <td>a.b.c.0<b>/24</b> </td> <td>+0.0.0.255 </td> <td>255.255.255.000 </td> <td>256 </td> <td>1 C </td> <td> </td></tr> <tr> <td>a.b.c.0<b>/23</b> </td> <td>+0.0.1.255 </td> <td>255.255.254.000 </td> <td>512 </td> <td>2 C </td> <td>c = 0 ... (2n) ... 254 </td></tr> <tr> <td>a.b.c.0<b>/22</b> </td> <td>+0.0.3.255 </td> <td>255.255.252.000 </td> <td>1,024 </td> <td>4 C </td> <td>c = 0 ... (4n) ... 252 </td></tr> <tr> <td>a.b.c.0<b>/21</b> </td> <td>+0.0.7.255 </td> <td>255.255.248.000 </td> <td>2,048 </td> <td>8 C </td> <td>c = 0 ... (8n) ... 248 </td></tr> <tr> <td>a.b.c.0<b>/20</b> </td> <td>+0.0.15.255 </td> <td>255.255.240.000 </td> <td>4,096 </td> <td>16 C </td> <td>c = 0 ... (16n) ... 240 </td></tr> <tr> <td>a.b.c.0<b>/19</b> </td> <td>+0.0.31.255 </td> <td>255.255.224.000 </td> <td>8,192 </td> <td>32 C </td> <td>c = 0 ... (32n) ... 224 </td></tr> <tr> <td>a.b.c.0<b>/18</b> </td> <td>+0.0.63.255 </td> <td>255.255.192.000 </td> <td>16,384 </td> <td>64 C </td> <td>c = 0, 64, 128, 192 </td></tr> <tr> <td>a.b.c.0<b>/17</b> </td> <td>+0.0.127.255 </td> <td>255.255.128.000 </td> <td>32,768 </td> <td>128 C </td> <td>c = 0, 128 </td></tr> <tr> <td>a.b.0.0<b>/16</b> </td> <td>+0.0.255.255 </td> <td>255.255.000.000 </td> <td>65,536 </td> <td>256 C = 1 B </td> <td> </td></tr> <tr> <td>a.b.0.0<b>/15</b> </td> <td>+0.1.255.255 </td> <td>255.254.000.000 </td> <td>131,072 </td> <td>2 B </td> <td>b = 0 ... (2n) ... 254 </td></tr> <tr> <td>a.b.0.0<b>/14</b> </td> <td>+0.3.255.255 </td> <td>255.252.000.000 </td> <td>262,144 </td> <td>4 B </td> <td>b = 0 ... (4n) ... 252 </td></tr> <tr> <td>a.b.0.0<b>/13</b> </td> <td>+0.7.255.255 </td> <td>255.248.000.000 </td> <td>524,288 </td> <td>8 B </td> <td>b = 0 ... (8n) ... 248 </td></tr> <tr> <td>a.b.0.0<b>/12</b> </td> <td>+0.15.255.255 </td> <td>255.240.000.000 </td> <td>1,048,576 </td> <td>16 B </td> <td>b = 0 ... (16n) ... 240 </td></tr> <tr> <td>a.b.0.0<b>/11</b> </td> <td>+0.31.255.255 </td> <td>255.224.000.000 </td> <td>2,097,152 </td> <td>32 B </td> <td>b = 0 ... (32n) ... 224 </td></tr> <tr> <td>a.b.0.0<b>/10</b> </td> <td>+0.63.255.255 </td> <td>255.192.000.000 </td> <td>4,194,304 </td> <td>64 B </td> <td>b = 0, 64, 128, 192 </td></tr> <tr> <td>a.b.0.0<b>/9</b> </td> <td>+0.127.255.255 </td> <td>255.128.000.000 </td> <td>8,388,608 </td> <td>128 B </td> <td>b = 0, 128 </td></tr> <tr> <td>a.0.0.0<b>/8</b> </td> <td>+0.255.255.255 </td> <td>255.000.000.000 </td> <td>16,777,216 </td> <td>256 B = 1 A </td> <td> </td></tr> <tr> <td>a.0.0.0<b>/7</b> </td> <td>+1.255.255.255 </td> <td>254.000.000.000 </td> <td>33,554,432 </td> <td>2 A </td> <td>a = 0 ... (2n) ... 254 </td></tr> <tr> <td>a.0.0.0<b>/6</b> </td> <td>+3.255.255.255 </td> <td>252.000.000.000 </td> <td>67,108,864 </td> <td>4 A </td> <td>a = 0 ... (4n) ... 252 </td></tr> <tr> <td>a.0.0.0<b>/5</b> </td> <td>+7.255.255.255 </td> <td>248.000.000.000 </td> <td>134,217,728 </td> <td>8 A </td> <td>a = 0 ... (8n) ... 248 </td></tr> <tr> <td>a.0.0.0<b>/4</b> </td> <td>+15.255.255.255 </td> <td>240.000.000.000 </td> <td>268,435,456 </td> <td>16 A </td> <td>a = 0 ... (16n) ... 240 </td></tr> <tr> <td>a.0.0.0<b>/3</b> </td> <td>+31.255.255.255 </td> <td>224.000.000.000 </td> <td>536,870,912 </td> <td>32 A </td> <td>a = 0 ... (32n) ... 224 </td></tr> <tr> <td>a.0.0.0<b>/2</b> </td> <td>+63.255.255.255 </td> <td>192.000.000.000 </td> <td>1,073,741,824 </td> <td>64 A </td> <td>a = 0, 64, 128, 192 </td></tr> <tr> <td>a.0.0.0<b>/1</b> </td> <td>+127.255.255.255 </td> <td>128.000.000.000 </td> <td>2,147,483,648 </td> <td>128 A </td> <td>a = 0, 128 </td></tr> <tr> <td>0.0.0.0<b>/0</b> </td> <td>+255.255.255.255 </td> <td>000.000.000.000 </td> <td>4,294,967,296 </td> <td>256 A </td> <td> </td></tr></tbody></table> <p>通常来说，子网中的第一个地址（主机标识符中的所有二进制零的地址）都保留用于引用网络本身，而最后一个地址用作广播地址用于网络；这样可以将可用于主机的地址数量减少2个。结果，主机标识符中只有一个二进制数字的<i><span class="ip地址"><span style="padding-right: 1px;">/</span><span style="padding-right: 1px;">31</span></span></i>网络将无法使用，因为这样的子网在减少之后将不提供可用的主机地址。<sup id="cite_ref-RFC_922_3-0" class="reference"><a href="#cite_note-RFC_922-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-RFC_1812_4-0" class="reference"><a href="#cite_note-RFC_1812-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup><a href="/wiki/RFC" title="RFC">RFC</a> <a href="//tools.ietf.org/html/rfc3021" class="extiw" title="rfc:3021">3021</a>为“全为一的主机”和“全为零的主机”规则创建了一个例外，以使<i><span class="ip地址"><span style="padding-right: 1px;">/</span><span style="padding-right: 1px;">31</span></span></i>网络可用于点对点链接。<i><span class="ip地址"><span style="padding-right: 1px;">/</span><span style="padding-right: 1px;">31</span></span></i>地址（单主机网络）必须通过明确的路由规则访问，因为在这种网络中没有网关的空间。 </p><p>在大于<i><span class="ip地址"><span style="padding-right: 1px;">/</span><span style="padding-right: 1px;">31</span></span></i>或<i><span class="ip地址"><span style="padding-right: 1px;">/</span><span style="padding-right: 1px;">32</span></span></i>的路由子网中，可用主机地址的数目通常减少两个，即保留作为广播地址的最大地址和标识网络本身的最小地址。<sup id="cite_ref-RFC_922_3-1" class="reference"><a href="#cite_note-RFC_922-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-RFC_1812_4-1" class="reference"><a href="#cite_note-RFC_1812-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="IPv6的CIDR块"><span id="IPv6.E7.9A.84CIDR.E5.9D.97"></span>IPv6的CIDR块</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1&action=edit&section=5" title="编辑章节：IPv6的CIDR块"><span>编辑</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure typeof="mw:File/Thumb"><a href="/wiki/File:IPv6_CIDR_table-en.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/3/38/IPv6_CIDR_table-en.svg/300px-IPv6_CIDR_table-en.svg.png" decoding="async" width="300" height="422" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/3/38/IPv6_CIDR_table-en.svg/450px-IPv6_CIDR_table-en.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/3/38/IPv6_CIDR_table-en.svg/600px-IPv6_CIDR_table-en.svg.png 2x" data-file-width="640" data-file-height="900" /></a><figcaption>IPv6的CIDR前缀表，显示了每个前缀对应的等效子网数以及主机标识符位数。</figcaption></figure> <p>IPv6中使用的地址大小允许在每个站点实现全球路由摘要并能保证足够的地址池。IPv6网络的标准子网大小是一个<i><span class="ip地址"><span style="padding-right: 1px;">/</span><span style="padding-right: 1px;">64</span></span></i>块，这是运行静态地址的自动配置所必需的。<sup id="cite_ref-RFC_4862_5-0" class="reference"><a href="#cite_note-RFC_4862-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup> </p><p>最初，IETF在<a href="/wiki/RFC" title="RFC">RFC</a> <a href="//tools.ietf.org/html/rfc3177" class="extiw" title="rfc:3177">3177</a>中提出建议，所有终端站点都应得到一个<i><span class="ip地址"><span style="padding-right: 1px;">/</span><span style="padding-right: 1px;">48</span></span></i>地址分配。<sup id="cite_ref-RFC_3177_6-0" class="reference"><a href="#cite_note-RFC_3177-6"><span class="cite-bracket">[</span>6<span class="cite-bracket">]</span></a></sup>但对实际需要和做法的批评和重新评价导致在<a href="/wiki/RFC" title="RFC">RFC</a> <a href="//tools.ietf.org/html/rfc6177" class="extiw" title="rfc:6177">6177</a><sup id="cite_ref-RFC_6177_7-0" class="reference"><a href="#cite_note-RFC_6177-7"><span class="cite-bracket">[</span>7<span class="cite-bracket">]</span></a></sup>中提出了更灵活的分配建议，即建议一些站点的分配要小得多，例如用于家庭网络的<i><span class="ip地址"><span style="padding-right: 1px;">/</span><span style="padding-right: 1px;">56</span></span></i>块。 </p><p>不同类型的网络线路可能需要不同的子网大小。<sup id="cite_ref-8" class="reference"><a href="#cite_note-8"><span class="cite-bracket">[</span>8<span class="cite-bracket">]</span></a></sup>子网掩码将网络标识符前缀的位数与接口标识符的位数分开。如果选择较小的前缀，所覆盖的网络数量就会减少，但每个网络中的地址会变的更多。<sup id="cite_ref-9" class="reference"><a href="#cite_note-9"><span class="cite-bracket">[</span>9<span class="cite-bracket">]</span></a></sup> </p> <div style="clear: both; height: 1em"></div> <pre>2001:0db8:0123:4567:89ab:cdef:1234:5678 |||| |||| |||| |||| |||| |||| |||| |||| |||| |||| |||| |||| |||| |||| |||| |||128 单端口和<a href="/wiki/%E5%9B%9E%E7%8E%AF" title="回环">回环</a> |||| |||| |||| |||| |||| |||| |||| |||127 路由器间点对点链接 |||| |||| |||| |||| |||| |||| |||| ||124 |||| |||| |||| |||| |||| |||| |||| |120 |||| |||| |||| |||| |||| |||| |||| 116 |||| |||| |||| |||| |||| |||| |||112 |||| |||| |||| |||| |||| |||| ||108 |||| |||| |||| |||| |||| |||| |104 |||| |||| |||| |||| |||| |||| 100 |||| |||| |||| |||| |||| |||96 |||| |||| |||| |||| |||| ||92 |||| |||| |||| |||| |||| |88 |||| |||| |||| |||| |||| 84 |||| |||| |||| |||| |||80 |||| |||| |||| |||| ||76 |||| |||| |||| |||| |72 |||| |||| |||| |||| 68 |||| |||| |||| |||64 单个LAN；<a href="/wiki/SLAAC" class="mw-redirect" title="SLAAC">SLAAC</a>的默认前缀大小 |||| |||| |||| ||60 非常有限的第6次部署(/60 = 16 /64块) |||| |||| |||| |56 最小的端口分配<sup id="cite_ref-RFC_6177_7-1" class="reference"><a href="#cite_note-RFC_6177-7"><span class="cite-bracket">[</span>7<span class="cite-bracket">]</span></a></sup>：例如家庭网络(/56 = 256 /64块) |||| |||| |||| 52 /52 = 4096 /64块 |||| |||| |||48 大型地址分配池的典型分配(/48 =65536 /64块) |||| |||| ||44 |||| |||| |40 |||| |||| 36 未来可能的<a href="/wiki/%E5%8C%BA%E5%9F%9F%E4%BA%92%E8%81%94%E7%BD%91%E6%B3%A8%E5%86%8C%E7%AE%A1%E7%90%86%E6%9C%BA%E6%9E%84" title="区域互联网注册管理机构">本地互联网注册</a>的 (LIR) 超小分配 |||| |||32 LIR最小分配 |||| ||28 LTR典型分配 |||| |24 LTR大型分配 |||| 20 LTR额外分配 |||16 ||12 IANA额外分配给区域因特网登记册表<sup id="cite_ref-10" class="reference"><a href="#cite_note-10"><span class="cite-bracket">[</span>10<span class="cite-bracket">]</span></a></sup> |8 4 </pre> <div class="mw-heading mw-heading2"><h2 id="历史背景"><span id=".E5.8E.86.E5.8F.B2.E8.83.8C.E6.99.AF"></span>历史背景</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1&action=edit&section=6" title="编辑章节：历史背景"><span>编辑</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>IP地址最初被描述为包含两部分：网络地址和主机地址。这种区分在IP网络里的路由中使用。 </p><p>在历史上，IP地址空间被分为三个<a href="/wiki/%E5%88%86%E7%B1%BB%E7%BD%91%E7%BB%9C" title="分类网络">分类网络</a>，这些类别有着固定长度的网络地址。网络的类别，以及网络地址，还有该网络上的主机数目都可以从地址的最高位得出。因为分类<a href="/wiki/%E8%B7%AF%E7%94%B1%E5%8D%8F%E8%AE%AE" title="路由协议">路由协议</a>不指定<a href="/wiki/%E5%AD%90%E7%BD%91" title="子网">子网</a>的<a href="/wiki/%E6%8E%A9%E7%A0%81" title="掩码">掩码</a>或前缀长度，<a href="/wiki/%E8%B7%AF%E7%94%B1%E5%99%A8" title="路由器">路由器</a>必须使用路由通告中的地址类别去得出子网掩码以建立路由表。 </p><p>随着原为实验性的TCP/IP网络在80年代转变为互联网，对更灵活的寻址方法的需求日益迫切。这就导致了<a href="/wiki/%E5%AD%90%E7%BD%91" title="子网">子网</a>和CIDR的相继发展。因为原来的类别已被忽略，所以现在的系统被叫做<b>无类别路由</b>。它为当今的<a href="/wiki/%E8%B7%AF%E7%94%B1%E5%8D%8F%E8%AE%AE" title="路由协议">路由协议</a>所支持，例如，<a href="/wiki/%E8%B7%AF%E7%94%B1%E4%BF%A1%E6%81%AF%E5%8D%8F%E8%AE%AE" title="路由信息协议">RIP-2</a>，<a href="/wiki/%E5%8A%A0%E5%BC%B7%E5%9E%8B%E9%96%98%E9%81%93%E9%96%93%E9%81%B8%E5%BE%91%E5%8D%94%E5%AE%9A" title="加強型閘道間選徑協定">EIGRP</a>，<a href="/wiki/%E4%B8%AD%E9%97%B4%E7%B3%BB%E7%BB%9F%E5%88%B0%E4%B8%AD%E9%97%B4%E7%B3%BB%E7%BB%9F" title="中间系统到中间系统">IS-IS</a>和<a href="/wiki/%E5%BC%80%E6%94%BE%E5%BC%8F%E6%9C%80%E7%9F%AD%E8%B7%AF%E5%BE%84%E4%BC%98%E5%85%88" title="开放式最短路径优先">OSPF</a>等，而相对的，原来的系统被叫做<b>分类路由</b>。 </p><p>可变长子网掩码（VLSM）和CIDR是相同的概念，不过一般只在历史上使用。它在RFC 950中首次被提及。 </p> <div class="mw-heading mw-heading2"><h2 id="外部链接"><span id=".E5.A4.96.E9.83.A8.E9.93.BE.E6.8E.A5"></span>外部链接</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1&action=edit&section=7" title="编辑章节：外部链接"><span>编辑</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a class="external mw-magiclink-rfc" rel="nofollow" href="https://tools.ietf.org/html/rfc1518">RFC 1518</a> - An Architecture for IP Address Allocation with CIDR</li> <li><a class="external mw-magiclink-rfc" rel="nofollow" href="https://tools.ietf.org/html/rfc4632">RFC 4632</a> - Classless Inter-domain Routing (CIDR): The Internet Address Assignment and</li></ul> <div class="mw-heading mw-heading2"><h2 id="参考文献"><span id=".E5.8F.82.E8.80.83.E6.96.87.E7.8C.AE"></span>参考文献</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1&action=edit&section=8" title="编辑章节：参考文献"><span>编辑</span></a><span class="mw-editsection-bracket">]</span></span></div> <div class="reflist" style="list-style-type: decimal;"> <ol class="references"> <li id="cite_note-RFC_1518-1"><span class="mw-cite-backlink"><b><a href="#cite_ref-RFC_1518_1-0">^</a></b></span> <span class="reference-text"><span class="citation IETF_document">Y. Rekhter; T. Li. <a rel="nofollow" class="external text" href="//tools.ietf.org/html/rfc1518">An Architecture for IP Address Allocation with CIDR</a>. September 1993. RFC 1518.</span><span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=An+Architecture+for+IP+Address+Allocation+with+CIDR&rft.aulast=Y.+Rekhter&rft.au=Y.+Rekhter&rft.au=T.+Li&rft.date=September+1993&rft_id=%2F%2Ftools.ietf.org%2Fhtml%2Frfc1518&rfr_id=info:sid/zh.wikipedia.org:%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1"><span style="display: none;"> </span></span></span> </li> <li id="cite_note-RFC_1519-2"><span class="mw-cite-backlink"><b><a href="#cite_ref-RFC_1519_2-0">^</a></b></span> <span class="reference-text"><span class="citation IETF_document">V. Fuller; T. Li; J. Yu; K. Varadhan. <a rel="nofollow" class="external text" href="//tools.ietf.org/html/rfc1519">Classless Inter-Domain Routing (CIDR): an Address Assignment and Aggregation Strategy</a>. September 1993. RFC 1519.</span><span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Classless+Inter-Domain+Routing+%28CIDR%29%3A+an+Address+Assignment+and+Aggregation+Strategy&rft.aulast=V.+Fuller&rft.au=V.+Fuller&rft.au=T.+Li&rft.au=J.+Yu&rft.au=K.+Varadhan&rft.date=September+1993&rft_id=%2F%2Ftools.ietf.org%2Fhtml%2Frfc1519&rfr_id=info:sid/zh.wikipedia.org:%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1"><span style="display: none;"> </span></span></span> </li> <li id="cite_note-RFC_922-3"><span class="mw-cite-backlink">^ <a href="#cite_ref-RFC_922_3-0"><sup><b>3.0</b></sup></a> <a href="#cite_ref-RFC_922_3-1"><sup><b>3.1</b></sup></a></span> <span class="reference-text"><span class="citation IETF_document">J. Mogul. <a rel="nofollow" class="external text" href="//tools.ietf.org/html/rfc922#section-7">Broadcasting Internet Datagrams in the Presence of Subnets</a>. October 1984: sec. 7. RFC 922.</span><span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Broadcasting+Internet+Datagrams+in+the+Presence+of+Subnets&rft.date=October+1984&rft.pages=sec.%26nbsp%3B7&rft_id=%2F%2Ftools.ietf.org%2Fhtml%2Frfc922%26%23035%3Bsection-7&rfr_id=info:sid/zh.wikipedia.org:%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1"><span style="display: none;"> </span></span></span> </li> <li id="cite_note-RFC_1812-4"><span class="mw-cite-backlink">^ <a href="#cite_ref-RFC_1812_4-0"><sup><b>4.0</b></sup></a> <a href="#cite_ref-RFC_1812_4-1"><sup><b>4.1</b></sup></a></span> <span class="reference-text"><span class="citation IETF_document">F. Baker. <a rel="nofollow" class="external text" href="//tools.ietf.org/html/rfc1812#section-4.2.3.1">Requirements for IP Version 4 Routers</a>. June 1995: sec. 4.2.3.1. RFC 1812.</span><span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Requirements+for+IP+Version+4+Routers&rft.date=June+1995&rft.pages=sec.%26nbsp%3B4.2.3.1&rft_id=%2F%2Ftools.ietf.org%2Fhtml%2Frfc1812%26%23035%3Bsection-4.2.3.1&rfr_id=info:sid/zh.wikipedia.org:%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1"><span style="display: none;"> </span></span></span> </li> <li id="cite_note-RFC_4862-5"><span class="mw-cite-backlink"><b><a href="#cite_ref-RFC_4862_5-0">^</a></b></span> <span class="reference-text"><a href="/wiki/RFC" title="RFC">RFC</a> <a href="//tools.ietf.org/html/rfc4862" class="extiw" title="rfc:4862">4862</a></span> </li> <li id="cite_note-RFC_3177-6"><span class="mw-cite-backlink"><b><a href="#cite_ref-RFC_3177_6-0">^</a></b></span> <span class="reference-text"><span class="citation IETF_document"> <a rel="nofollow" class="external text" href="//tools.ietf.org/html/rfc3177">IAB/IESG Recommendation on IPv6 Address Allocations to Sites</a>. IAB/IESG. September 2001. RFC 3177.</span><span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=IAB%2FIESG+Recommendation+on+IPv6+Address+Allocations+to+Sites&rft.date=September+2001&rft.pub=IAB%2FIESG&rft_id=%2F%2Ftools.ietf.org%2Fhtml%2Frfc3177&rfr_id=info:sid/zh.wikipedia.org:%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1"><span style="display: none;"> </span></span></span> </li> <li id="cite_note-RFC_6177-7"><span class="mw-cite-backlink">^ <a href="#cite_ref-RFC_6177_7-0"><sup><b>7.0</b></sup></a> <a href="#cite_ref-RFC_6177_7-1"><sup><b>7.1</b></sup></a></span> <span class="reference-text"><span class="citation IETF_document">T. Narten; G. Huston; L. Roberts. <a rel="nofollow" class="external text" href="//tools.ietf.org/html/rfc6177">IPv6 Address Assignment to End Sites</a>. March 2011. RFC 6177.</span><span class="Z3988" title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=IPv6+Address+Assignment+to+End+Sites&rft.aulast=T.+Narten&rft.au=T.+Narten&rft.au=G.+Huston&rft.au=L.+Roberts&rft.date=March+2011&rft_id=%2F%2Ftools.ietf.org%2Fhtml%2Frfc6177&rfr_id=info:sid/zh.wikipedia.org:%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1"><span style="display: none;"> </span></span></span> </li> <li id="cite_note-8"><span class="mw-cite-backlink"><b><a href="#cite_ref-8">^</a></b></span> <span class="reference-text"><cite class="citation web"><a rel="nofollow" class="external text" href="http://www.getipv6.info/index.php/IPv6_Addressing_Plans">ARIN IPv6 Addressing Plans</a>. Getipv6.info. 2016-03-25 <span class="reference-accessdate"> [<span class="nowrap">2018-03-12</span>]</span>. （原始内容<a rel="nofollow" class="external text" href="https://web.archive.org/web/20130112084917/http://www.getipv6.info/index.php/IPv6_Addressing_Plans">存档</a>于2013-01-12）.</cite><span title="ctx_ver=Z39.88-2004&rfr_id=info%3Asid%2Fzh.wikipedia.org%3A%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1&rft.btitle=ARIN+IPv6+Addressing+Plans&rft.date=2016-03-25&rft.genre=unknown&rft.pub=Getipv6.info&rft_id=http%3A%2F%2Fwww.getipv6.info%2Findex.php%2FIPv6_Addressing_Plans&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook" class="Z3988"><span style="display:none;"> </span></span></span> </li> <li id="cite_note-9"><span class="mw-cite-backlink"><b><a href="#cite_ref-9">^</a></b></span> <span class="reference-text"><cite class="citation web"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20110203130851/http://ripe.net/info/info-services/addressing.html">RIPE IP Allocation Rates</a>. （<a rel="nofollow" class="external text" href="https://www.ripe.net/info/info-services/addressing.html">原始内容</a>存档于2011-02-03）.</cite><span title="ctx_ver=Z39.88-2004&rfr_id=info%3Asid%2Fzh.wikipedia.org%3A%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1&rft.btitle=RIPE+IP+Allocation+Rates&rft.genre=unknown&rft_id=https%3A%2F%2Fwww.ripe.net%2Finfo%2Finfo-services%2Faddressing.html&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook" class="Z3988"><span style="display:none;"> </span></span></span> </li> <li id="cite_note-10"><span class="mw-cite-backlink"><b><a href="#cite_ref-10">^</a></b></span> <span class="reference-text"><cite class="citation web"><a rel="nofollow" class="external text" href="http://www.iana.org/assignments/ipv6-unicast-address-assignments/ipv6-unicast-address-assignments.xml">IANA IPv6 unicast address assignments</a>. Iana.org. <span class="reference-accessdate"> [<span class="nowrap">2018-03-12</span>]</span>. （原始内容<a rel="nofollow" class="external text" href="https://web.archive.org/web/20110524220539/http://www.iana.org/assignments/ipv6-unicast-address-assignments/ipv6-unicast-address-assignments.xml">存档</a>于2011-05-24）.</cite><span title="ctx_ver=Z39.88-2004&rfr_id=info%3Asid%2Fzh.wikipedia.org%3A%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1&rft.btitle=IANA+IPv6+unicast+address+assignments&rft.genre=unknown&rft.pub=Iana.org&rft_id=http%3A%2F%2Fwww.iana.org%2Fassignments%2Fipv6-unicast-address-assignments%2Fipv6-unicast-address-assignments.xml&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook" class="Z3988"><span style="display:none;"> </span></span></span> </li> </ol></div>    </div><noscript><img src="https://login.wikimedia.org/wiki/Special:CentralAutoLogin/start?type=1x1" alt="" width="1" height="1" style="border: none; position: absolute;"></noscript> <div class="printfooter" data-nosnippet="">检索自“<a dir="ltr" href="https://zh.wikipedia.org/w/index.php?title=无类别域间路由&oldid=79295521">https://zh.wikipedia.org/w/index.php?title=无类别域间路由&oldid=79295521</a>”</div></div> <div id="catlinks" class="catlinks" data-mw="interface"><div id="mw-normal-catlinks" class="mw-normal-catlinks"><a href="/wiki/Special:%E9%A1%B5%E9%9D%A2%E5%88%86%E7%B1%BB" title="Special:页面分类">分类</a>：<ul><li><a href="/wiki/Category:%E4%BA%92%E8%81%94%E7%BD%91%E6%A0%87%E5%87%86" title="Category:互联网标准">互联网标准</a></li><li><a href="/wiki/Category:%E4%BA%92%E8%81%94%E7%BD%91%E7%BB%93%E6%9E%84" title="Category:互联网结构">互联网结构</a></li><li><a href="/wiki/Category:%E8%B7%AF%E7%94%B1" title="Category:路由">路由</a></li><li><a href="/wiki/Category:IP%E5%9C%B0%E5%9D%80" title="Category:IP地址">IP地址</a></li></ul></div><div id="mw-hidden-catlinks" class="mw-hidden-catlinks mw-hidden-cats-hidden">隐藏分类：<ul><li><a href="/wiki/Category:%E8%87%AA2018%E5%B9%B48%E6%9C%88%E9%9C%80%E8%A6%81%E5%BE%9E%E5%A4%96%E8%AA%9E%E7%B6%AD%E5%9F%BA%E7%99%BE%E7%A7%91%E7%BF%BB%E8%AD%AF%E7%9A%84%E6%A2%9D%E7%9B%AE" title="Category:自2018年8月需要從外語維基百科翻譯的條目">自2018年8月需要從外語維基百科翻譯的條目</a></li><li><a href="/wiki/Category:%E9%9C%80%E8%A6%81%E5%BE%9E%E5%A4%96%E8%AA%9E%E7%B6%AD%E5%9F%BA%E7%99%BE%E7%A7%91%E7%BF%BB%E8%AD%AF%E7%9A%84%E6%A2%9D%E7%9B%AE" title="Category:需要從外語維基百科翻譯的條目">需要從外語維基百科翻譯的條目</a></li><li><a href="/wiki/Category:%E8%87%AA2018%E5%B9%B48%E6%9C%88%E5%BE%85%E6%9B%B4%E6%96%B0%E6%9D%A1%E7%9B%AE" title="Category:自2018年8月待更新条目">自2018年8月待更新条目</a></li><li><a href="/wiki/Category:%E5%90%AB%E6%9C%89%E5%A4%9A%E4%B8%AA%E9%97%AE%E9%A2%98%E7%9A%84%E6%9D%A1%E7%9B%AE" title="Category:含有多个问题的条目">含有多个问题的条目</a></li><li><a href="/wiki/Category:%E5%90%AB%E6%9C%89%E8%8B%B1%E8%AA%9E%E7%9A%84%E6%A2%9D%E7%9B%AE" title="Category:含有英語的條目">含有英語的條目</a></li><li><a href="/wiki/Category:%E8%87%AA2013%E5%B9%B42%E6%9C%88%E6%9C%89%E6%9C%AA%E5%88%97%E6%98%8E%E6%9D%A5%E6%BA%90%E8%AF%AD%E5%8F%A5%E7%9A%84%E6%9D%A1%E7%9B%AE" title="Category:自2013年2月有未列明来源语句的条目">自2013年2月有未列明来源语句的条目</a></li><li><a href="/wiki/Category:%E4%BD%BF%E7%94%A8RFC%E9%AD%94%E6%9C%AF%E9%93%BE%E6%8E%A5%E7%9A%84%E9%A1%B5%E9%9D%A2" title="Category:使用RFC魔术链接的页面">使用RFC魔术链接的页面</a></li></ul></div></div> </div> </main> </div> <div class="mw-footer-container"> <footer id="footer" class="mw-footer" > <ul id="footer-info"> <li id="footer-info-lastmod"> 本页面最后修订于2023年10月9日 (星期一) 16:42。</li> <li id="footer-info-copyright">本站的全部文字在<a rel="nofollow" class="external text" href="//creativecommons.org/licenses/by-sa/4.0/deed.zh">知识共享署名-相同方式共享 4.0协议</a>之条款下提供，附加条款亦可能应用。（请参阅<a class="external text" href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Terms_of_Use">使用条款</a>）<br /> Wikipedia®和维基百科标志是<a rel="nofollow" class="external text" href="https://wikimediafoundation.org/zh">维基媒体基金会</a>的注册商标；维基™是维基媒体基金会的商标。<br /> 维基媒体基金会是按美国国內稅收法501(c)(3)登记的<a class="external text" href="https://donate.wikimedia.org/wiki/Special:MyLanguage/Tax_deductibility">非营利慈善机构</a>。<br /></li> </ul> <ul id="footer-places"> <li id="footer-places-privacy"><a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Privacy_policy">隐私政策</a></li> <li id="footer-places-about"><a href="/wiki/Wikipedia:%E5%85%B3%E4%BA%8E">关于维基百科</a></li> <li id="footer-places-disclaimers"><a href="/wiki/Wikipedia:%E5%85%8D%E8%B4%A3%E5%A3%B0%E6%98%8E">免责声明</a></li> <li id="footer-places-wm-codeofconduct"><a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Universal_Code_of_Conduct">行为准则</a></li> <li id="footer-places-developers"><a href="https://developer.wikimedia.org">开发者</a></li> <li id="footer-places-statslink"><a href="https://stats.wikimedia.org/#/zh.wikipedia.org">统计</a></li> <li id="footer-places-cookiestatement"><a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Cookie_statement">Cookie声明</a></li> <li id="footer-places-mobileview"><a href="//zh.m.wikipedia.org/w/index.php?title=%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1&mobileaction=toggle_view_mobile" class="noprint stopMobileRedirectToggle">手机版视图</a></li> </ul> <ul id="footer-icons" class="noprint"> <li id="footer-copyrightico"><a href="https://wikimediafoundation.org/" class="cdx-button cdx-button--fake-button cdx-button--size-large cdx-button--fake-button--enabled"><img src="/static/images/footer/wikimedia-button.svg" width="84" height="29" alt="Wikimedia Foundation" loading="lazy"></a></li> <li id="footer-poweredbyico"><a href="https://www.mediawiki.org/" class="cdx-button cdx-button--fake-button cdx-button--size-large cdx-button--fake-button--enabled"><img src="/w/resources/assets/poweredby_mediawiki.svg" alt="Powered by MediaWiki" width="88" height="31" loading="lazy"></a></li> </ul> </footer> </div> </div> </div> <div class="vector-settings" id="p-dock-bottom"> <ul></ul> </div><script>(RLQ=window.RLQ||[]).push(function(){mw.config.set({"wgHostname":"mw-web.codfw.main-6df7948d6c-hfrps","wgBackendResponseTime":208,"wgPageParseReport":{"limitreport":{"cputime":"0.571","walltime":"0.780","ppvisitednodes":{"value":6284,"limit":1000000},"postexpandincludesize":{"value":257351,"limit":2097152},"templateargumentsize":{"value":13722,"limit":2097152},"expansiondepth":{"value":24,"limit":100},"expensivefunctioncount":{"value":5,"limit":500},"unstrip-depth":{"value":0,"limit":20},"unstrip-size":{"value":22967,"limit":5000000},"entityaccesscount":{"value":0,"limit":400},"timingprofile":["100.00% 509.080 1 -total"," 30.05% 152.995 1 Template:Multiple_issues"," 24.10% 122.684 1 Template:Reflist"," 22.15% 112.775 1 Template:Lang-en"," 18.86% 96.036 3 Template:Ambox"," 17.99% 91.581 1 Template:Request_translation"," 13.26% 67.509 6 Template:Cite_IETF"," 11.58% 58.964 6 Template:Citation/core"," 10.41% 53.006 1 Template:NoteTA"," 8.85% 45.063 3 Template:Cite_web"]},"scribunto":{"limitreport-timeusage":{"value":"0.200","limit":"10.000"},"limitreport-memusage":{"value":19412754,"limit":52428800}},"cachereport":{"origin":"mw-web.eqiad.main-554bb6b4dc-9bcrn","timestamp":"20241127135309","ttl":2592000,"transientcontent":false}}});});</script> <script type="application/ld+json">{"@context":"https:\/\/schema.org","@type":"Article","name":"\u65e0\u7c7b\u522b\u57df\u95f4\u8def\u7531","url":"https:\/\/zh.wikipedia.org\/wiki\/%E6%97%A0%E7%B1%BB%E5%88%AB%E5%9F%9F%E9%97%B4%E8%B7%AF%E7%94%B1","sameAs":"http:\/\/www.wikidata.org\/entity\/Q646589","mainEntity":"http:\/\/www.wikidata.org\/entity\/Q646589","author":{"@type":"Organization","name":"\u7ef4\u57fa\u5a92\u4f53\u9879\u76ee\u8d21\u732e\u8005"},"publisher":{"@type":"Organization","name":"Wikimedia Foundation, Inc.","logo":{"@type":"ImageObject","url":"https:\/\/www.wikimedia.org\/static\/images\/wmf-hor-googpub.png"}},"datePublished":"2008-12-10T15:26:27Z","dateModified":"2023-10-09T16:42:36Z","headline":"\u5bf9IP\u5730\u5740\u8fdb\u884c\u5f52\u7c7b\u7684\u65b9\u6cd5"}</script> </body> </html>