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class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-main-menu.unpin">nascondi</button> </div> <div id="p-navigation" class="vector-menu mw-portlet mw-portlet-navigation" > <div class="vector-menu-heading"> Navigazione </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="n-mainpage-description" class="mw-list-item"><a href="/wiki/Pagina_principale" title="Visita la pagina principale [z]" accesskey="z"><span>Pagina principale</span></a></li><li id="n-recentchanges" class="mw-list-item"><a href="/wiki/Speciale:UltimeModifiche" title="Elenco delle ultime modifiche del sito [r]" accesskey="r"><span>Ultime modifiche</span></a></li><li id="n-randompage" class="mw-list-item"><a href="/wiki/Speciale:PaginaCasuale" title="Mostra una pagina a caso [x]" accesskey="x"><span>Una voce a caso</span></a></li><li id="n-nearby-pages-title" class="mw-list-item"><a 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il colore del testo" > <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="Aspetto" > <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">Aspetto</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/?wmf_source=donate&wmf_medium=sidebar&wmf_campaign=it.wikipedia.org&uselang=it" class=""><span>Fai una donazione</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=Speciale:CreaUtenza&returnto=IPv4" title="Si consiglia di registrarsi e di effettuare l'accesso, anche se non è obbligatorio" class=""><span>registrati</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=Speciale:Entra&returnto=IPv4" title="Si consiglia di effettuare l'accesso, anche se non è obbligatorio [o]" accesskey="o" class=""><span>entra</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="Altre opzioni" > <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="Strumenti personali" > <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">Strumenti personali</span> </label> <div class="vector-dropdown-content"> <div id="p-personal" class="vector-menu mw-portlet mw-portlet-personal user-links-collapsible-item" title="Menu utente" > <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/?wmf_source=donate&wmf_medium=sidebar&wmf_campaign=it.wikipedia.org&uselang=it"><span>Fai una donazione</span></a></li><li id="pt-createaccount" class="user-links-collapsible-item mw-list-item"><a href="/w/index.php?title=Speciale:CreaUtenza&returnto=IPv4" title="Si consiglia di registrarsi e di effettuare l'accesso, anche se non è obbligatorio"><span class="vector-icon mw-ui-icon-userAdd mw-ui-icon-wikimedia-userAdd"></span> <span>registrati</span></a></li><li id="pt-login" class="user-links-collapsible-item mw-list-item"><a href="/w/index.php?title=Speciale:Entra&returnto=IPv4" title="Si consiglia di effettuare l'accesso, anche se non è obbligatorio [o]" accesskey="o"><span class="vector-icon mw-ui-icon-logIn mw-ui-icon-wikimedia-logIn"></span> <span>entra</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"> Pagine per utenti anonimi <a href="/wiki/Aiuto:Benvenuto" aria-label="Ulteriori informazioni sulla contribuzione"><span>ulteriori informazioni</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/Speciale:MieiContributi" title="Un elenco delle modifiche fatte da questo indirizzo IP [y]" accesskey="y"><span>contributi</span></a></li><li id="pt-anontalk" class="mw-list-item"><a href="/wiki/Speciale:MieDiscussioni" title="Discussioni sulle modifiche fatte da questo indirizzo IP [n]" accesskey="n"><span>discussioni</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="Sito"> <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="Indice" 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">Indice</h2> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-toc.pin">sposta nella barra laterale</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-toc.unpin">nascondi</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">Inizio</div> </a> </li> <li id="toc-Struttura_del_pacchetto" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Struttura_del_pacchetto"> <div class="vector-toc-text"> <span class="vector-toc-numb">1</span> <span>Struttura del pacchetto</span> </div> </a> <button aria-controls="toc-Struttura_del_pacchetto-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Attiva/disattiva la sottosezione Struttura del pacchetto</span> </button> <ul id="toc-Struttura_del_pacchetto-sublist" class="vector-toc-list"> <li id="toc-Header" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Header"> <div class="vector-toc-text"> <span class="vector-toc-numb">1.1</span> <span>Header</span> </div> </a> <ul id="toc-Header-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Data" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Data"> <div class="vector-toc-text"> <span class="vector-toc-numb">1.2</span> <span>Data</span> </div> </a> <ul id="toc-Data-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-Indirizzamento_IPv4" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Indirizzamento_IPv4"> <div class="vector-toc-text"> <span class="vector-toc-numb">2</span> <span>Indirizzamento IPv4</span> </div> </a> <button aria-controls="toc-Indirizzamento_IPv4-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Attiva/disattiva la sottosezione Indirizzamento IPv4</span> </button> <ul id="toc-Indirizzamento_IPv4-sublist" class="vector-toc-list"> <li id="toc-Notazione_decimale_puntata" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Notazione_decimale_puntata"> <div class="vector-toc-text"> <span class="vector-toc-numb">2.1</span> <span>Notazione decimale puntata</span> </div> </a> <ul id="toc-Notazione_decimale_puntata-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Indirizzi_particolari" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Indirizzi_particolari"> <div class="vector-toc-text"> <span class="vector-toc-numb">2.2</span> <span>Indirizzi particolari</span> </div> </a> <ul id="toc-Indirizzi_particolari-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Indirizzamento_a_classi" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Indirizzamento_a_classi"> <div class="vector-toc-text"> <span class="vector-toc-numb">2.3</span> <span>Indirizzamento a classi</span> </div> </a> <ul id="toc-Indirizzamento_a_classi-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Limiti" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Limiti"> <div class="vector-toc-text"> <span class="vector-toc-numb">2.4</span> <span>Limiti</span> </div> </a> <ul id="toc-Limiti-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Indirizzamento_senza_classi" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Indirizzamento_senza_classi"> <div class="vector-toc-text"> <span class="vector-toc-numb">2.5</span> <span>Indirizzamento senza classi</span> </div> </a> <ul id="toc-Indirizzamento_senza_classi-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Enti_di_gestione" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Enti_di_gestione"> <div class="vector-toc-text"> <span class="vector-toc-numb">2.6</span> <span>Enti di gestione</span> </div> </a> <ul id="toc-Enti_di_gestione-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-Note" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Note"> <div class="vector-toc-text"> <span class="vector-toc-numb">3</span> <span>Note</span> </div> </a> <ul id="toc-Note-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Voci_correlate" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Voci_correlate"> <div class="vector-toc-text"> <span class="vector-toc-numb">4</span> <span>Voci correlate</span> </div> </a> <ul id="toc-Voci_correlate-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Altri_progetti" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Altri_progetti"> <div class="vector-toc-text"> <span class="vector-toc-numb">5</span> <span>Altri progetti</span> </div> </a> <ul id="toc-Altri_progetti-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Collegamenti_esterni" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Collegamenti_esterni"> <div class="vector-toc-text"> <span class="vector-toc-numb">6</span> <span>Collegamenti esterni</span> </div> </a> <ul id="toc-Collegamenti_esterni-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="Indice" class="vector-toc-landmark"> <div id="vector-page-titlebar-toc" class="vector-dropdown vector-page-titlebar-toc vector-button-flush-left" title="Indice" > <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="Mostra/Nascondi l'indice" > <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">Mostra/Nascondi l'indice</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">IPv4</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="Vai a una voce in un'altra lingua. Disponibile in 49 lingue" > <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-49" 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">49 lingue</span> </label> <div class="vector-dropdown-content"> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li class="interlanguage-link interwiki-ar badge-Q17437796 badge-featuredarticle mw-list-item" title="voce in vetrina"><a href="https://ar.wikipedia.org/wiki/%D8%A8%D8%B1%D9%88%D8%AA%D9%88%D9%83%D9%88%D9%84_%D8%A7%D9%84%D8%A5%D9%86%D8%AA%D8%B1%D9%86%D8%AA_(%D8%A7%D9%84%D8%A5%D8%B5%D8%AF%D8%A7%D8%B1_%D8%A7%D9%84%D8%B1%D8%A7%D8%A8%D8%B9)" title="بروتوكول الإنترنت (الإصدار الرابع) - arabo" lang="ar" hreflang="ar" data-title="بروتوكول الإنترنت (الإصدار الرابع)" data-language-autonym="العربية" data-language-local-name="arabo" class="interlanguage-link-target"><span>العربية</span></a></li><li class="interlanguage-link interwiki-az mw-list-item"><a href="https://az.wikipedia.org/wiki/IPv4" title="IPv4 - azerbaigiano" lang="az" hreflang="az" data-title="IPv4" data-language-autonym="Azərbaycanca" data-language-local-name="azerbaigiano" class="interlanguage-link-target"><span>Azərbaycanca</span></a></li><li class="interlanguage-link interwiki-be mw-list-item"><a href="https://be.wikipedia.org/wiki/IPv4" title="IPv4 - bielorusso" lang="be" hreflang="be" data-title="IPv4" data-language-autonym="Беларуская" data-language-local-name="bielorusso" class="interlanguage-link-target"><span>Беларуская</span></a></li><li class="interlanguage-link interwiki-bg mw-list-item"><a href="https://bg.wikipedia.org/wiki/IPv4" title="IPv4 - bulgaro" lang="bg" hreflang="bg" data-title="IPv4" data-language-autonym="Български" data-language-local-name="bulgaro" class="interlanguage-link-target"><span>Български</span></a></li><li class="interlanguage-link interwiki-bn mw-list-item"><a href="https://bn.wikipedia.org/wiki/%E0%A6%86%E0%A6%87%E0%A6%AA%E0%A6%BF%E0%A6%AD%E0%A6%BF%E0%A7%AA" title="আইপিভি৪ - bengalese" lang="bn" hreflang="bn" data-title="আইপিভি৪" data-language-autonym="বাংলা" data-language-local-name="bengalese" class="interlanguage-link-target"><span>বাংলা</span></a></li><li class="interlanguage-link interwiki-bs mw-list-item"><a href="https://bs.wikipedia.org/wiki/IPv4" title="IPv4 - bosniaco" lang="bs" hreflang="bs" data-title="IPv4" data-language-autonym="Bosanski" data-language-local-name="bosniaco" class="interlanguage-link-target"><span>Bosanski</span></a></li><li class="interlanguage-link interwiki-cs mw-list-item"><a href="https://cs.wikipedia.org/wiki/IPv4" title="IPv4 - ceco" lang="cs" hreflang="cs" data-title="IPv4" data-language-autonym="Čeština" data-language-local-name="ceco" class="interlanguage-link-target"><span>Čeština</span></a></li><li class="interlanguage-link interwiki-da mw-list-item"><a href="https://da.wikipedia.org/wiki/IPv4" title="IPv4 - danese" lang="da" hreflang="da" data-title="IPv4" data-language-autonym="Dansk" data-language-local-name="danese" class="interlanguage-link-target"><span>Dansk</span></a></li><li class="interlanguage-link interwiki-de mw-list-item"><a href="https://de.wikipedia.org/wiki/IPv4" title="IPv4 - tedesco" lang="de" hreflang="de" data-title="IPv4" data-language-autonym="Deutsch" data-language-local-name="tedesco" class="interlanguage-link-target"><span>Deutsch</span></a></li><li class="interlanguage-link interwiki-el mw-list-item"><a href="https://el.wikipedia.org/wiki/IPv4" title="IPv4 - greco" lang="el" hreflang="el" data-title="IPv4" data-language-autonym="Ελληνικά" data-language-local-name="greco" class="interlanguage-link-target"><span>Ελληνικά</span></a></li><li class="interlanguage-link interwiki-en mw-list-item"><a href="https://en.wikipedia.org/wiki/IPv4" title="IPv4 - inglese" lang="en" hreflang="en" data-title="IPv4" data-language-autonym="English" data-language-local-name="inglese" 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/IPv4" title="IPv4 - spagnolo" lang="es" hreflang="es" data-title="IPv4" data-language-autonym="Español" data-language-local-name="spagnolo" class="interlanguage-link-target"><span>Español</span></a></li><li class="interlanguage-link interwiki-et mw-list-item"><a href="https://et.wikipedia.org/wiki/IPv4" title="IPv4 - estone" lang="et" hreflang="et" data-title="IPv4" data-language-autonym="Eesti" data-language-local-name="estone" class="interlanguage-link-target"><span>Eesti</span></a></li><li class="interlanguage-link interwiki-eu mw-list-item"><a href="https://eu.wikipedia.org/wiki/IPv4" title="IPv4 - basco" lang="eu" hreflang="eu" data-title="IPv4" data-language-autonym="Euskara" data-language-local-name="basco" class="interlanguage-link-target"><span>Euskara</span></a></li><li class="interlanguage-link interwiki-fa mw-list-item"><a href="https://fa.wikipedia.org/wiki/%D9%BE%D8%B1%D9%88%D8%AA%DA%A9%D9%84_%D8%A7%DB%8C%D9%86%D8%AA%D8%B1%D9%86%D8%AA_%D9%86%D8%B3%D8%AE%D9%87_%DB%B4" title="پروتکل اینترنت نسخه ۴ - persiano" lang="fa" hreflang="fa" data-title="پروتکل اینترنت نسخه ۴" data-language-autonym="فارسی" data-language-local-name="persiano" class="interlanguage-link-target"><span>فارسی</span></a></li><li class="interlanguage-link interwiki-fi mw-list-item"><a href="https://fi.wikipedia.org/wiki/IPv4" title="IPv4 - finlandese" lang="fi" hreflang="fi" data-title="IPv4" data-language-autonym="Suomi" data-language-local-name="finlandese" class="interlanguage-link-target"><span>Suomi</span></a></li><li class="interlanguage-link interwiki-fr mw-list-item"><a href="https://fr.wikipedia.org/wiki/IPv4" title="IPv4 - francese" lang="fr" hreflang="fr" data-title="IPv4" data-language-autonym="Français" data-language-local-name="francese" class="interlanguage-link-target"><span>Français</span></a></li><li class="interlanguage-link interwiki-gl mw-list-item"><a href="https://gl.wikipedia.org/wiki/Protocolo_IPv4" title="Protocolo IPv4 - galiziano" lang="gl" hreflang="gl" data-title="Protocolo IPv4" data-language-autonym="Galego" data-language-local-name="galiziano" class="interlanguage-link-target"><span>Galego</span></a></li><li class="interlanguage-link interwiki-gu mw-list-item"><a href="https://gu.wikipedia.org/wiki/IPv4" title="IPv4 - gujarati" lang="gu" hreflang="gu" data-title="IPv4" data-language-autonym="ગુજરાતી" data-language-local-name="gujarati" class="interlanguage-link-target"><span>ગુજરાતી</span></a></li><li class="interlanguage-link interwiki-he mw-list-item"><a href="https://he.wikipedia.org/wiki/IPv4" title="IPv4 - ebraico" lang="he" hreflang="he" data-title="IPv4" data-language-autonym="עברית" data-language-local-name="ebraico" class="interlanguage-link-target"><span>עברית</span></a></li><li class="interlanguage-link interwiki-hi mw-list-item"><a href="https://hi.wikipedia.org/wiki/%E0%A4%87%E0%A4%82%E0%A4%9F%E0%A4%B0%E0%A4%A8%E0%A5%87%E0%A4%9F_%E0%A4%AA%E0%A5%8D%E0%A4%B0%E0%A5%8B%E0%A4%9F%E0%A5%8B%E0%A4%95%E0%A5%89%E0%A4%B2_4" title="इंटरनेट प्रोटोकॉल 4 - hindi" lang="hi" hreflang="hi" data-title="इंटरनेट प्रोटोकॉल 4" data-language-autonym="हिन्दी" data-language-local-name="hindi" class="interlanguage-link-target"><span>हिन्दी</span></a></li><li class="interlanguage-link interwiki-hr mw-list-item"><a href="https://hr.wikipedia.org/wiki/IPv4" title="IPv4 - croato" lang="hr" hreflang="hr" data-title="IPv4" data-language-autonym="Hrvatski" data-language-local-name="croato" class="interlanguage-link-target"><span>Hrvatski</span></a></li><li class="interlanguage-link interwiki-hy mw-list-item"><a href="https://hy.wikipedia.org/wiki/IPv4" title="IPv4 - armeno" lang="hy" hreflang="hy" data-title="IPv4" data-language-autonym="Հայերեն" data-language-local-name="armeno" class="interlanguage-link-target"><span>Հայերեն</span></a></li><li class="interlanguage-link interwiki-id mw-list-item"><a href="https://id.wikipedia.org/wiki/Alamat_IP_versi_4" title="Alamat IP versi 4 - indonesiano" lang="id" hreflang="id" data-title="Alamat IP versi 4" data-language-autonym="Bahasa Indonesia" data-language-local-name="indonesiano" class="interlanguage-link-target"><span>Bahasa Indonesia</span></a></li><li class="interlanguage-link interwiki-ja mw-list-item"><a href="https://ja.wikipedia.org/wiki/IPv4" title="IPv4 - giapponese" lang="ja" hreflang="ja" data-title="IPv4" data-language-autonym="日本語" data-language-local-name="giapponese" 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/IPv4" title="IPv4 - coreano" lang="ko" hreflang="ko" data-title="IPv4" data-language-autonym="한국어" data-language-local-name="coreano" class="interlanguage-link-target"><span>한국어</span></a></li><li class="interlanguage-link interwiki-ln mw-list-item"><a href="https://ln.wikipedia.org/wiki/IPv4" title="IPv4 - lingala" lang="ln" hreflang="ln" data-title="IPv4" data-language-autonym="Lingála" data-language-local-name="lingala" class="interlanguage-link-target"><span>Lingála</span></a></li><li class="interlanguage-link interwiki-lv mw-list-item"><a href="https://lv.wikipedia.org/wiki/IPv4" title="IPv4 - lettone" lang="lv" hreflang="lv" data-title="IPv4" data-language-autonym="Latviešu" data-language-local-name="lettone" 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/IPv4" title="IPv4 - macedone" lang="mk" hreflang="mk" data-title="IPv4" data-language-autonym="Македонски" data-language-local-name="macedone" class="interlanguage-link-target"><span>Македонски</span></a></li><li class="interlanguage-link interwiki-ml mw-list-item"><a href="https://ml.wikipedia.org/wiki/%E0%B4%90%E0%B4%AA%E0%B4%BF%E0%B4%B5%E0%B4%BF4" title="ഐപിവി4 - malayalam" lang="ml" hreflang="ml" data-title="ഐപിവി4" data-language-autonym="മലയാളം" data-language-local-name="malayalam" class="interlanguage-link-target"><span>മലയാളം</span></a></li><li class="interlanguage-link interwiki-mn mw-list-item"><a href="https://mn.wikipedia.org/wiki/IPv4" title="IPv4 - mongolo" lang="mn" hreflang="mn" data-title="IPv4" data-language-autonym="Монгол" data-language-local-name="mongolo" class="interlanguage-link-target"><span>Монгол</span></a></li><li class="interlanguage-link interwiki-ms mw-list-item"><a href="https://ms.wikipedia.org/wiki/IPv4" title="IPv4 - malese" lang="ms" hreflang="ms" data-title="IPv4" data-language-autonym="Bahasa Melayu" data-language-local-name="malese" class="interlanguage-link-target"><span>Bahasa Melayu</span></a></li><li class="interlanguage-link interwiki-nl mw-list-item"><a href="https://nl.wikipedia.org/wiki/Internet_Protocol_versie_4" title="Internet Protocol versie 4 - olandese" lang="nl" hreflang="nl" data-title="Internet Protocol versie 4" data-language-autonym="Nederlands" data-language-local-name="olandese" 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/IPv4" title="IPv4 - norvegese bokmål" lang="nb" hreflang="nb" data-title="IPv4" data-language-autonym="Norsk bokmål" data-language-local-name="norvegese bokmål" 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/IPv4" title="IPv4 - polacco" lang="pl" hreflang="pl" data-title="IPv4" data-language-autonym="Polski" data-language-local-name="polacco" 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/IPv4" title="IPv4 - portoghese" lang="pt" hreflang="pt" data-title="IPv4" data-language-autonym="Português" data-language-local-name="portoghese" 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/IPv4" title="IPv4 - russo" lang="ru" hreflang="ru" data-title="IPv4" data-language-autonym="Русский" data-language-local-name="russo" class="interlanguage-link-target"><span>Русский</span></a></li><li class="interlanguage-link interwiki-sh mw-list-item"><a href="https://sh.wikipedia.org/wiki/IPv4" title="IPv4 - serbo-croato" lang="sh" hreflang="sh" data-title="IPv4" data-language-autonym="Srpskohrvatski / српскохрватски" data-language-local-name="serbo-croato" class="interlanguage-link-target"><span>Srpskohrvatski / српскохрватски</span></a></li><li class="interlanguage-link interwiki-sk mw-list-item"><a href="https://sk.wikipedia.org/wiki/IPv4" title="IPv4 - slovacco" lang="sk" hreflang="sk" data-title="IPv4" data-language-autonym="Slovenčina" data-language-local-name="slovacco" class="interlanguage-link-target"><span>Slovenčina</span></a></li><li class="interlanguage-link interwiki-sr mw-list-item"><a href="https://sr.wikipedia.org/wiki/IPv4" title="IPv4 - serbo" lang="sr" hreflang="sr" data-title="IPv4" data-language-autonym="Српски / srpski" data-language-local-name="serbo" 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/IPv4" title="IPv4 - svedese" lang="sv" hreflang="sv" data-title="IPv4" data-language-autonym="Svenska" data-language-local-name="svedese" class="interlanguage-link-target"><span>Svenska</span></a></li><li class="interlanguage-link interwiki-ta mw-list-item"><a href="https://ta.wikipedia.org/wiki/%E0%AE%87%E0%AE%A3%E0%AF%88%E0%AE%AF_%E0%AE%A8%E0%AF%86%E0%AE%B1%E0%AE%BF%E0%AE%AE%E0%AF%81%E0%AE%B1%E0%AF%88%E0%AE%AA%E0%AF%8D_%E0%AE%AA%E0%AE%A4%E0%AE%BF%E0%AE%AA%E0%AF%8D%E0%AE%AA%E0%AF%81_4" title="இணைய நெறிமுறைப் பதிப்பு 4 - tamil" lang="ta" hreflang="ta" data-title="இணைய நெறிமுறைப் பதிப்பு 4" data-language-autonym="தமிழ்" data-language-local-name="tamil" class="interlanguage-link-target"><span>தமிழ்</span></a></li><li class="interlanguage-link interwiki-tr mw-list-item"><a href="https://tr.wikipedia.org/wiki/IPv4" title="IPv4 - turco" lang="tr" hreflang="tr" data-title="IPv4" data-language-autonym="Türkçe" data-language-local-name="turco" 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/IPv4" title="IPv4 - ucraino" lang="uk" hreflang="uk" data-title="IPv4" data-language-autonym="Українська" data-language-local-name="ucraino" 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/IPv4" title="IPv4 - vietnamita" lang="vi" hreflang="vi" data-title="IPv4" data-language-autonym="Tiếng Việt" data-language-local-name="vietnamita" class="interlanguage-link-target"><span>Tiếng Việt</span></a></li><li class="interlanguage-link interwiki-wuu mw-list-item"><a href="https://wuu.wikipedia.org/wiki/IPv4" title="IPv4 - wu" lang="wuu" hreflang="wuu" data-title="IPv4" data-language-autonym="吴语" data-language-local-name="wu" class="interlanguage-link-target"><span>吴语</span></a></li><li class="interlanguage-link interwiki-yo mw-list-item"><a href="https://yo.wikipedia.org/wiki/IPv4" title="IPv4 - yoruba" lang="yo" hreflang="yo" data-title="IPv4" data-language-autonym="Yorùbá" data-language-local-name="yoruba" class="interlanguage-link-target"><span>Yorùbá</span></a></li><li class="interlanguage-link interwiki-zh mw-list-item"><a href="https://zh.wikipedia.org/wiki/IPv4" title="IPv4 - cinese" lang="zh" hreflang="zh" data-title="IPv4" data-language-autonym="中文" data-language-local-name="cinese" class="interlanguage-link-target"><span>中文</span></a></li><li class="interlanguage-link interwiki-zh-yue mw-list-item"><a href="https://zh-yue.wikipedia.org/wiki/IPv4" title="IPv4 - cantonese" lang="yue" hreflang="yue" data-title="IPv4" data-language-autonym="粵語" data-language-local-name="cantonese" class="interlanguage-link-target"><span>粵語</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/Q11103#sitelinks-wikipedia" title="Modifica collegamenti interlinguistici" class="wbc-editpage">Modifica collegamenti</a></span></div> </div> </div> </div> </header> <div class="vector-page-toolbar"> <div class="vector-page-toolbar-container"> <div id="left-navigation"> <nav 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id="ca-edit" class="collapsible vector-tab-noicon mw-list-item"><a href="/w/index.php?title=IPv4&action=edit" title="Modifica il wikitesto di questa pagina [e]" accesskey="e"><span>Modifica wikitesto</span></a></li><li id="ca-history" class="vector-tab-noicon mw-list-item"><a href="/w/index.php?title=IPv4&action=history" title="Versioni precedenti di questa pagina [h]" accesskey="h"><span>Cronologia</span></a></li> </ul> </div> </div> </nav> <nav class="vector-page-tools-landmark" aria-label="Strumenti pagine"> <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="Strumenti" > <label id="vector-page-tools-dropdown-label" for="vector-page-tools-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button 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data-event-name="pinnable-header.vector-page-tools.unpin">nascondi</button> </div> <div id="p-cactions" class="vector-menu mw-portlet mw-portlet-cactions emptyPortlet vector-has-collapsible-items" title="Altre opzioni" > <div class="vector-menu-heading"> Azioni </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/IPv4"><span>Leggi</span></a></li><li id="ca-more-ve-edit" class="vector-more-collapsible-item mw-list-item"><a href="/w/index.php?title=IPv4&veaction=edit" title="Modifica questa pagina [v]" accesskey="v"><span>Modifica</span></a></li><li id="ca-more-edit" class="collapsible vector-more-collapsible-item mw-list-item"><a href="/w/index.php?title=IPv4&action=edit" title="Modifica il wikitesto di questa pagina [e]" accesskey="e"><span>Modifica wikitesto</span></a></li><li id="ca-more-history" class="vector-more-collapsible-item mw-list-item"><a href="/w/index.php?title=IPv4&action=history"><span>Cronologia</span></a></li> </ul> </div> </div> <div id="p-tb" class="vector-menu mw-portlet mw-portlet-tb" > <div class="vector-menu-heading"> Generale </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="t-whatlinkshere" class="mw-list-item"><a href="/wiki/Speciale:PuntanoQui/IPv4" title="Elenco di tutte le pagine che sono collegate a questa [j]" accesskey="j"><span>Puntano qui</span></a></li><li id="t-recentchangeslinked" class="mw-list-item"><a href="/wiki/Speciale:ModificheCorrelate/IPv4" rel="nofollow" title="Elenco delle ultime modifiche alle pagine collegate a questa [k]" accesskey="k"><span>Modifiche correlate</span></a></li><li id="t-permalink" class="mw-list-item"><a href="/w/index.php?title=IPv4&oldid=143518487" title="Collegamento permanente a questa versione di questa pagina"><span>Link permanente</span></a></li><li id="t-info" class="mw-list-item"><a href="/w/index.php?title=IPv4&action=info" title="Ulteriori informazioni su questa pagina"><span>Informazioni pagina</span></a></li><li id="t-cite" class="mw-list-item"><a href="/w/index.php?title=Speciale:Cita&page=IPv4&id=143518487&wpFormIdentifier=titleform" title="Informazioni su come citare questa pagina"><span>Cita questa voce</span></a></li><li id="t-urlshortener" class="mw-list-item"><a href="/w/index.php?title=Speciale:UrlShortener&url=https%3A%2F%2Fit.wikipedia.org%2Fwiki%2FIPv4"><span>Ottieni URL breve</span></a></li><li id="t-urlshortener-qrcode" class="mw-list-item"><a href="/w/index.php?title=Speciale:QrCode&url=https%3A%2F%2Fit.wikipedia.org%2Fwiki%2FIPv4"><span>Scarica codice QR</span></a></li> </ul> </div> </div> <div id="p-coll-print_export" class="vector-menu mw-portlet mw-portlet-coll-print_export" > <div class="vector-menu-heading"> Stampa/esporta </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="coll-create_a_book" class="mw-list-item"><a href="/w/index.php?title=Speciale:Libro&bookcmd=book_creator&referer=IPv4"><span>Crea un libro</span></a></li><li id="coll-download-as-rl" class="mw-list-item"><a href="/w/index.php?title=Speciale:DownloadAsPdf&page=IPv4&action=show-download-screen"><span>Scarica come PDF</span></a></li><li id="t-print" class="mw-list-item"><a href="/w/index.php?title=IPv4&printable=yes" title="Versione stampabile di questa pagina [p]" accesskey="p"><span>Versione stampabile</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"> In altri progetti </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:IPv4" hreflang="en"><span>Wikimedia Commons</span></a></li><li class="wb-otherproject-link wb-otherproject-wikibooks mw-list-item"><a href="https://it.wikibooks.org/wiki/Internet:_architettura_e_protocolli/Protocollo_IPv4" hreflang="it"><span>Wikibooks</span></a></li><li class="wb-otherproject-link wb-otherproject-wikifunctions mw-list-item"><a href="https://www.wikifunctions.org/wiki/Z10476" hreflang="en"><span>Wikifunctions</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/Q11103" title="Collegamento all'elemento connesso dell'archivio dati [g]" accesskey="g"><span>Elemento Wikidata</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="Strumenti pagine"> <div id="vector-page-tools-pinned-container" class="vector-pinned-container"> </div> </nav> <nav class="vector-appearance-landmark" aria-label="Aspetto"> <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">Aspetto</div> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-appearance.pin">sposta nella barra laterale</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-appearance.unpin">nascondi</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> <div id="siteSub" class="noprint">Da Wikipedia, l'enciclopedia libera.</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="it" dir="ltr"><style data-mw-deduplicate="TemplateStyles:r133964453">.mw-parser-output .avviso .mbox-text-div>div,.mw-parser-output .avviso .mbox-text-full-div>div{font-size:90%}.mw-parser-output .avviso .mbox-image{flex-basis:52px;flex-grow:0;flex-shrink:0}.mw-parser-output .avviso .mbox-text-full-div .hide-when-compact{display:block}</style><div style="" class="ambox metadata plainlinks avviso avviso-contenuto"> <div class="avviso-immagine mbox-image noprint"><span typeof="mw:File"><a href="/wiki/File:Question_book-4.svg" class="mw-file-description" title="Niente fonti!"><img alt="Niente fonti!" src="//upload.wikimedia.org/wikipedia/commons/thumb/6/64/Question_book-4.svg/45px-Question_book-4.svg.png" decoding="async" width="45" height="35" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/6/64/Question_book-4.svg/68px-Question_book-4.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/6/64/Question_book-4.svg/90px-Question_book-4.svg.png 2x" data-file-width="262" data-file-height="204" /></a></span></div> <div class="avviso-testo mbox-text"> <div class="mbox-text-div"><b>Questa voce o sezione  sull'argomento informatica <a href="/wiki/Wikipedia:Uso_delle_fonti" title="Wikipedia:Uso delle fonti">non cita le fonti necessarie</a> o quelle presenti sono insufficienti</b>. <div class="hide-when-compact"> <div class="noprint"><hr />Puoi <a class="external text" href="https://it.wikipedia.org/w/index.php?title=IPv4&action=edit">migliorare questa voce</a> aggiungendo citazioni da <a href="/wiki/Wikipedia:Fonti_attendibili" title="Wikipedia:Fonti attendibili">fonti attendibili</a> secondo le <a href="/wiki/Wikipedia:Uso_delle_fonti" title="Wikipedia:Uso delle fonti">linee guida sull'uso delle fonti</a>. Segui i suggerimenti del <a href="/wiki/Progetto:Informatica" title="Progetto:Informatica">progetto di riferimento</a>.</div> </div> </div> </div> </div> <figure typeof="mw:File/Thumb"><a href="/wiki/File:IPv4_address_structure_and_writing_systems-en.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/6/66/IPv4_address_structure_and_writing_systems-en.svg/500px-IPv4_address_structure_and_writing_systems-en.svg.png" decoding="async" width="400" height="136" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/6/66/IPv4_address_structure_and_writing_systems-en.svg/960px-IPv4_address_structure_and_writing_systems-en.svg.png 1.5x" data-file-width="1138" data-file-height="386" /></a><figcaption>Le varie parti di un IPv4</figcaption></figure> <p><b>IPv4</b> (<i>Internet Protocol version 4</i>) è la quarta revisione dell'<a href="/wiki/Internet_Protocol" title="Internet Protocol">Internet Protocol</a>. Il protocollo è descritto nell'<a class="external mw-magiclink-rfc" rel="nofollow" href="https://datatracker.ietf.org/doc/html/rfc791">RFC 791</a>, pubblicato dalla <a href="/wiki/Internet_Engineering_Task_Force" title="Internet Engineering Task Force">IETF</a> nel settembre 1981, ed è il più usato a <a href="/wiki/Livello_di_rete" title="Livello di rete">livello di rete</a>, poiché fa parte della <a href="/wiki/Suite_di_protocolli_Internet" title="Suite di protocolli Internet">suite di protocolli Internet</a>. </p><p>Nel 1998 è stata suggerita una nuova versione del protocollo Internet, denominata <a href="/wiki/IPv6" title="IPv6">IPv6</a>, a causa del problema della <a href="/wiki/Saturazione_di_IPv4" title="Saturazione di IPv4">saturazione di IPv4</a>. Al 2021, l'IPv6 risulta tuttavia meno utilizzato rispetto alla versione 4<sup id="cite_ref-1" class="reference"><a href="#cite_note-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup>. </p> <meta property="mw:PageProp/toc" /> <div class="mw-heading mw-heading2"><h2 id="Struttura_del_pacchetto">Struttura del pacchetto</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=IPv4&veaction=edit&section=1" title="Modifica la sezione Struttura del pacchetto" class="mw-editsection-visualeditor"><span>modifica</span></a><span class="mw-editsection-divider"> | </span><a href="/w/index.php?title=IPv4&action=edit&section=1" title="Edit section's source code: Struttura del pacchetto"><span>modifica wikitesto</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Un pacchetto IPv4 è composto da una sezione <i>header</i> e da una sezione data. </p> <div class="mw-heading mw-heading3"><h3 id="Header">Header</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=IPv4&veaction=edit&section=2" title="Modifica la sezione Header" class="mw-editsection-visualeditor"><span>modifica</span></a><span class="mw-editsection-divider"> | </span><a href="/w/index.php?title=IPv4&action=edit&section=2" title="Edit section's source code: Header"><span>modifica wikitesto</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>L'<i>header</i> del pacchetto IPv4 consiste in 14 campi di cui 1 opzionale chiamato con il nome di <i>Options</i>. I campi sono inseriti col byte più significativo messo per primo (notazione <i><a href="/wiki/Big-endian" class="mw-redirect" title="Big-endian">big-endian</a></i>) e all'interno dei singoli byte il bit più significativo è il primo (quello di indice 0). </p> <table class="wikitable" style="margin: 0 auto; text-align: center;"> <tbody><tr align="center"> <th width="4%"><i>Offsets</i> </th> <th>Ottetto </th> <th colspan="8">0 </th> <th colspan="8">1 </th> <th colspan="8">2 </th> <th colspan="8">3 </th></tr> <tr> <th>Ottetto </th> <th><a href="/wiki/Bit" title="Bit">Bit</a> </th> <th style="width:2.6%">0 </th> <th style="width:2.6%">1 </th> <th style="width:2.6%">2 </th> <th style="width:2.6%">3 </th> <th style="width:2.6%">4 </th> <th style="width:2.6%">5 </th> <th style="width:2.6%">6 </th> <th style="width:2.6%">7 </th> <th style="width:2.6%">8 </th> <th style="width:2.6%">9 </th> <th style="width:2.6%">10 </th> <th style="width:2.6%">11 </th> <th style="width:2.6%">12 </th> <th style="width:2.6%">13 </th> <th style="width:2.6%">14 </th> <th style="width:2.6%">15 </th> <th style="width:2.6%">16 </th> <th style="width:2.6%">17 </th> <th style="width:2.6%">18 </th> <th style="width:2.6%">19 </th> <th style="width:2.6%">20 </th> <th style="width:2.6%">21 </th> <th style="width:2.6%">22 </th> <th style="width:2.6%">23 </th> <th style="width:2.6%">24 </th> <th style="width:2.6%">25 </th> <th style="width:2.6%">26 </th> <th style="width:2.6%">27 </th> <th style="width:2.6%">28 </th> <th style="width:2.6%">29 </th> <th style="width:2.6%">30 </th> <th style="width:2.6%">31 </th></tr> <tr> <th>0 </th> <th>0 </th> <td colspan="4"><a href="#Version"><i>Version</i></a> </td> <td colspan="4"><a href="#IHL"><i>IHL</i></a> </td> <td colspan="6"><a href="#DSCP">DSCP</a> </td> <td colspan="2"><a href="#ECN">ECN</a> </td> <td colspan="16"><a href="#Total_Length"><i>Total length</i></a> </td></tr> <tr> <th>4 </th> <th>32 </th> <td colspan="16"><a href="#Identification"><i>Identification</i></a> </td> <td colspan="3"><a href="#Flags"><i>Flags</i></a> </td> <td colspan="13"><a href="#Fragment_offset"><i>Fragment offset</i></a> </td></tr> <tr> <th>8 </th> <th>64 </th> <td colspan="8"><a href="#TTL"><i>Time to live</i></a> </td> <td colspan="8"><a href="#Protocol"><i>Protocol</i></a> </td> <td colspan="16"><a href="#Header_checksum"><i>Header</i> checksum</a> </td></tr> <tr> <th>12 </th> <th>96 </th> <td colspan="32"><a href="#Source_address"><i>Source address</i></a> </td></tr> <tr> <th>16 </th> <th>128 </th> <td colspan="32"><a href="#Destination_address"><i>Destination address</i></a> </td></tr> <tr> <th>20 </th> <th>160 </th> <td colspan="32" rowspan="3"><a href="#Options"><i>Options</i></a> (se IHL > 5) </td></tr> <tr> <th>⋮ </th> <th>⋮ </th></tr> <tr> <th>56 </th> <th>448 </th></tr></tbody></table> <dl><dt><span id="Version">Version</span></dt> <dd>Indica la versione del <a href="/wiki/Pacchetto_(reti)" title="Pacchetto (reti)">pacchetto</a> IP: per IPv4, ha valore 4 (da qui il nome IPv4);</dd> <dt><span id="IHL"></span><span id="Internet_Header_Length_(IHL)">Internet Header Length (IHL)</span></dt> <dd>Indica la lunghezza (in <a href="/wiki/Word" class="mw-redirect" title="Word">word</a> da <span class="nowrap"><span data-sort-value="7001320000000000000♠"></span>32 <a href="/wiki/Bit" title="Bit">bit</a></span>) dell'<i>header</i> del pacchetto IP ovvero l'offset del campo dati; tale lunghezza può variare da <span class="nowrap"><span data-sort-value="7000500000000000000♠"></span>5 <a href="/wiki/Word" class="mw-redirect" title="Word">word</a></span> (<span class="nowrap"><span data-sort-value="7001200000000000000♠"></span>20 byte</span>) a <span class="nowrap"><span data-sort-value="7001150000000000000♠"></span>15 word</span> (<span class="nowrap"><span data-sort-value="7001600000000000000♠"></span>60 byte</span>) a seconda della presenza e della lunghezza del campo facoltativo <i>Options</i></dd> <dt><span id="DSCP"></span><span id="Differentiated_Services_Code_Point_(DSCP)">Differentiated Services Code Point (DSCP)</span></dt> <dd>Originariamente definito come <i><a href="/wiki/Type_of_Service" title="Type of Service">type of service</a></i> (ToS), questo campo specifica i <i><a href="/wiki/Differentiated_services" title="Differentiated services">differentiated services</a></i> (DiffServ). La trasmissione di dati in tempo reale fa uso del campo DSCP. Un esempio è <a href="/wiki/Voice_over_IP" title="Voice over IP">voice over IP</a> (VoIP), che viene utilizzato per servizi vocali interattivi.</dd> <dt><span id="ECN"></span><span id="Explicit_Congestion_Notification_(ECN)">Explicit Congestion Notification (ECN)</span></dt> <dd>Questo campo permette una notifica <i>end-to-end</i> della <a href="/wiki/Controllo_della_congestione" title="Controllo della congestione">congestione della rete</a> senza perdita di pacchetti. ECN è una funzionalità opzionale disponibile quando entrambi gli endpoint la supportano ed è efficace quando anche la rete sottostante la supporta.</dd> <dt><span id="Total_Length">Total Length</span></dt> <dd>Indica la dimensione (in byte) dell'intero pacchetto, comprendendo <i>header</i> e dati; tale lunghezza può variare da un minimo di <span class="nowrap"><span data-sort-value="7001200000000000000♠"></span>20 byte</span> (<i>header</i> minimo e campo dati vuoto) ad un massimo di <span class="nowrap"><span data-sort-value="7004655350000000000♠"></span>65<span style="margin-left:.25em;">535</span> byte</span>. In ogni momento, ad ogni host è richiesto di essere in grado di gestire datagrammi aventi una dimensione minima di <span class="nowrap"><span data-sort-value="7002576000000000000♠"></span>576 byte</span> mentre sono autorizzati, se necessario, a frammentare datagrammi di dimensione maggiore</dd> <dt><span id="Identification">Identification</span></dt> <dd>Utilizzato, come da specifiche iniziali, per identificare in modo univoco i vari frammenti in cui può essere stato "spezzato" un pacchetto IP. Alcune sperimentazioni successive hanno però suggerito di utilizzare questo campo per altri scopi, come aggiungere la funzionalità di tracciamento dei pacchetti;</dd> <dt><span id="Flags">Flags</span></dt> <dd>Bit utilizzati per il controllo del protocollo e della frammentazione dei datagrammi: <ul><li>Reserved - sempre settato a 0. Come <a href="/wiki/Pesce_d%27aprile" title="Pesce d'aprile">pesce d'aprile</a>, in <a class="external mw-magiclink-rfc" rel="nofollow" href="https://datatracker.ietf.org/doc/html/rfc3514">RFC 3514</a> si è proposto di utilizzarlo come e<i>vil bit</i>;</li> <li>DF (<i>don't fragment</i>) - se settato a 1 indica che il pacchetto non deve essere frammentato; se tale pacchetto non può essere inoltrato da un host senza essere frammentato, viene semplicemente scartato. Questo può risultare utile per "ispezionare" la capacità di gestione dei vari host del percorso di <i><a href="/wiki/Routing" class="mw-redirect" title="Routing">routing</a></i>;</li> <li>MF (<i>more fragments</i>) - se settato a 0 indica che il pacchetto è l'ultimo frammento o il solo frammento del pacchetto originario, pertanto tutti gli altri suoi frammenti hanno il bit MF settato a 1. Naturalmente, questo bit sarà sempre 0 anche in tutti i datagrammi che non sono stati frammentati.</li></ul></dd></dl> <dl><dt><span id="Fragment_offset">Fragment offset</span></dt> <dd>Indica l'offset (misurato in blocchi di 8 byte) di un particolare frammento relativamente all'inizio del pacchetto IP originale: il primo frammento ha offset 0. L'offset massimo risulta pertanto pari a <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^{16})-8=}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mo stretchy="false">(</mo> <msup> <mn>2</mn> <mrow class="MJX-TeXAtom-ORD"> <mn>16</mn> </mrow> </msup> <mo stretchy="false">)</mo> <mo>−</mo> <mn>8</mn> <mo>=</mo> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle (2^{16})-8=}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/8fe82ce9bc3ce962d57d4a062a540cd3c7edda59" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:11.304ex; height:3.176ex;" alt="{\displaystyle (2^{16})-8=}" /></span> <span class="nowrap"><span data-sort-value="7004655280000000000♠"></span>65<span style="margin-left:.25em;">528</span> byte</span> che, includendo l'header, potrebbe eccedere la dimensione massima di <span class="nowrap"><span data-sort-value="7004655350000000000♠"></span>65<span style="margin-left:.25em;">535</span> byte</span> di un pacchetto IP;</dd> <dt><span id="TTL"></span><span id="Time_to_live_(TTL)">Time to live (TTL)</span></dt> <dd>Indica il tempo di vita (<i><a href="/wiki/Time_to_live" title="Time to live">time to live</a></i>) del pacchetto, necessario per evitarne la persistenza indefinita sulla rete nel caso in cui non si riesca a recapitarlo al destinatario. Storicamente il TTL misurava i "secondi di vita" del pacchetto, mentre ora esso misura il numero di "salti" da nodo a nodo della rete: ogni router che riceve il pacchetto prima di inoltrarlo ne decrementa il TTL (modificando di conseguenza anche il campo <i>header checksum</i>), quando questo arriva a zero il pacchetto non viene più inoltrato ma scartato. Tipicamente, quando un pacchetto viene scartato per esaurimento del TTL, viene automaticamente inviato un messaggio <a href="/wiki/Internet_Control_Message_Protocol" title="Internet Control Message Protocol">ICMP</a> al mittente del pacchetto, specificando il codice di richiesta scaduta; la ricezione di questo messaggio ICMP è alla base del meccanismo di <i><a href="/wiki/Traceroute" title="Traceroute">traceroute</a></i>;</dd> <dt><span id="Protocol">Protocol</span></dt> <dd>Indica il codice associato al <a href="/wiki/Protocollo_di_rete" title="Protocollo di rete">protocollo</a> utilizzato nel campo dati del pacchetto IP: per esempio al protocollo <a href="/wiki/Transmission_Control_Protocol" title="Transmission Control Protocol">TCP</a> è associato il codice <i>6</i>, ad <a href="/wiki/User_Datagram_Protocol" title="User Datagram Protocol">UDP</a> il codice 17, mentre ad <a href="/wiki/IPv6" title="IPv6">IPv6</a> è associato il codice 41. La lista dei codici dei vari protocolli, inizialmente definita in <a class="external mw-magiclink-rfc" rel="nofollow" href="https://datatracker.ietf.org/doc/html/rfc790">RFC 790</a>, è mantenuta e gestita dalla <a href="/wiki/Internet_Assigned_Numbers_Authority" title="Internet Assigned Numbers Authority">Internet Assigned Numbers Authority</a>.</dd> <dt><span id="Header_checksum">Header checksum</span></dt> <dd>È un campo usato per il controllo degli errori dell'<i>header</i>. Ad ogni <i>hop</i>, il checksum viene ricalcolato (secondo la definizione data in <a href="/wiki/Request_for_Comments" title="Request for Comments">RFC</a> 791) e confrontato con il valore di questo campo: se non c'è corrispondenza il pacchetto viene scartato. È da notare che non viene effettuato alcun controllo sulla presenza di errori nel campo <i>data</i> deputandolo ai livelli superiori;</dd> <dt><span id="Source_address">Source address</span></dt> <dd>Indica l'indirizzo IP associato all'host del mittente del pacchetto.</dd> <dd>Da notare che questo indirizzo potrebbe non essere quello del "vero" mittente nel caso di traduzioni mediante <a href="/wiki/Network_address_translation" title="Network address translation">NAT</a>. Infatti, qualora un host intermedio effettui questa traduzione, sostituisce l'indirizzo del mittente con uno proprio, premurandosi poi di ripristinare l'indirizzo originario su tutti i messaggi di risposta che gli arrivano destinati al mittente originario;</dd> <dt><span id="Destination_address">Destination address</span></dt> <dd>Indica l'indirizzo IP associato all'host del destinatario del pacchetto e segue le medesime regole del campo <i>source address</i>;</dd> <dt><span id="Options">Options</span></dt> <dd>Opzioni (facoltative e non molto usate) per usi più specifici del protocollo, come informazioni sui router;</dd> <dd>Si ricorda che il valore del campo <i>IHL</i> deve essere sufficientemente grande da includere anche tutte le opzioni e, nel caso queste siano più corte di una word, il padding necessario a completare i <span class="nowrap"><span data-sort-value="7001320000000000000♠"></span>32 bit</span>. Inoltre, nel caso in cui la lista di opzioni non coincida con la fine dell'<i>header</i>, occorre aggiungere in coda ad essa un marcatore <i>EOL</i> (<i>end of options list</i>).</dd> <dd>C'è da notare infine che, potendo causare problemi di sicurezza, l'uso delle opzioni LSSR e SSRR (<i>loose</i> e <i>strict source and record route</i>, componenti del <i><a href="/wiki/Source_routing_(IP)" title="Source routing (IP)">source routing</a></i>) è scoraggiato e molti router bloccano i datagrammi che contengono queste opzioni.</dd></dl> <div class="mw-heading mw-heading3"><h3 id="Data">Data</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=IPv4&veaction=edit&section=3" title="Modifica la sezione Data" class="mw-editsection-visualeditor"><span>modifica</span></a><span class="mw-editsection-divider"> | </span><a href="/w/index.php?title=IPv4&action=edit&section=3" title="Edit section's source code: Data"><span>modifica wikitesto</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Il payload del pacchetto non è incluso nel checksum. Il suo contenuto viene interpretato in base al valore del campo dell'intestazione protocollo. </p><p>Alcuni dei protocolli payload più comuni includono: </p> <table class="wikitable"> <tbody><tr> <th>Numero di protocollo</th> <th>Nome del protocollo</th> <th>Abbreviazione </th></tr> <tr> <td>1</td> <td><a href="/wiki/Internet_Control_Message_Protocol" title="Internet Control Message Protocol">Internet Control Message Protocol</a></td> <td>ICMP </td></tr> <tr> <td>2</td> <td><a href="/wiki/Internet_Group_Management_Protocol" title="Internet Group Management Protocol">Internet Group Management Protocol</a></td> <td>IGMP </td></tr> <tr> <td>6</td> <td><a href="/wiki/Transmission_Control_Protocol" title="Transmission Control Protocol">Transmission Control Protocol</a></td> <td>TCP </td></tr> <tr> <td>17</td> <td><a href="/wiki/User_Datagram_Protocol" title="User Datagram Protocol">User Datagram Protocol</a></td> <td>UDP </td></tr> <tr> <td>41</td> <td><a href="/wiki/IPv6#Tunneling" title="IPv6">IPv6 encapsulation</a></td> <td>ENCAP </td></tr> <tr> <td>89</td> <td><a href="/wiki/Open_Shortest_Path_First" title="Open Shortest Path First">Open Shortest Path First</a></td> <td>OSPF </td></tr> <tr> <td>132</td> <td><a href="/wiki/Stream_Control_Transmission_Protocol" title="Stream Control Transmission Protocol">Stream Control Transmission Protocol</a></td> <td>SCTP </td></tr></tbody></table> <div class="mw-heading mw-heading2"><h2 id="Indirizzamento_IPv4">Indirizzamento IPv4</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=IPv4&veaction=edit&section=4" title="Modifica la sezione Indirizzamento IPv4" class="mw-editsection-visualeditor"><span>modifica</span></a><span class="mw-editsection-divider"> | </span><a href="/w/index.php?title=IPv4&action=edit&section=4" title="Edit section's source code: Indirizzamento IPv4"><span>modifica wikitesto</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>L'indirizzo IPv4 è formato da <span class="nowrap"><span data-sort-value="7001320000000000000♠"></span>32 bit</span>, esso è univoco sulla <a href="/wiki/Rete_telematica" class="mw-redirect" title="Rete telematica">rete</a> di cui fa parte. Tale indirizzo, inoltre, non va assegnato all'<a href="/wiki/Host" title="Host">host</a>, ma alle connessioni fisiche alla <a href="/wiki/Rete_telematica" class="mw-redirect" title="Rete telematica">rete</a> che l'host possiede (nel cast di host multicollegati o di <a href="/wiki/Dispositivi_di_rete" class="mw-redirect" title="Dispositivi di rete">dispositivi di rete</a>). Si è però verificato che i primi paesi in cui si è diffuso Internet e all'interno di essi i primi provider, si sono "accaparrati" un numero di IP proporzionalmente sbilanciato. Gli ultimi provider hanno pertanto dovuto ricorrere ad un sistema per ovviare alla scarsità degli IP a loro attribuiti. Hanno pertanto considerato gli utenti a loro connessi di una intera città come un'unica LAN e pertanto tutti dotati dello stesso IP. </p><p>Concettualmente l'indirizzo IP si compone di due parti: </p> <ol><li>identificatore di <a href="/wiki/Rete_telematica" class="mw-redirect" title="Rete telematica">rete</a> e precisamente della <a href="/wiki/Sottorete" title="Sottorete">sottorete</a>;</li> <li>identificatore di host.</li></ol> <div class="mw-heading mw-heading3"><h3 id="Notazione_decimale_puntata">Notazione decimale puntata</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=IPv4&veaction=edit&section=5" title="Modifica la sezione Notazione decimale puntata" class="mw-editsection-visualeditor"><span>modifica</span></a><span class="mw-editsection-divider"> | </span><a href="/w/index.php?title=IPv4&action=edit&section=5" title="Edit section's source code: Notazione decimale puntata"><span>modifica wikitesto</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Per semplificarne la lettura, ogni indirizzo IP viene descritto con 4 numeri in base decimale, in modo che ognuno rappresenti un byte (il valore di un byte varia da 0 a 255 quando lo consideriamo in base dieci), separati dal simbolo "punto"; un esempio di indirizzo IPv4 è <code>192.0.34.166</code>. </p> <div class="mw-heading mw-heading3"><h3 id="Indirizzi_particolari">Indirizzi particolari</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=IPv4&veaction=edit&section=6" title="Modifica la sezione Indirizzi particolari" class="mw-editsection-visualeditor"><span>modifica</span></a><span class="mw-editsection-divider"> | </span><a href="/w/index.php?title=IPv4&action=edit&section=6" title="Edit section's source code: Indirizzi particolari"><span>modifica wikitesto</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Ogni indirizzo in cui l'identificativo host presenta tutti 0 si riferisce alla rete, mentre se tutti i bit di questo identificativo sono a 1, l'indirizzo si riferisce ad una trasmissione <a href="/wiki/Broadcast" class="mw-redirect" title="Broadcast">broadcast</a> diretta. </p><p>In pratica quando ad un <a href="/wiki/Router" title="Router">router</a> arriva un pacchetto in cui la parte di host dell'indirizzo presenta tutti i bit a 1, esso esegue un broadcast a tutti i nodi della sotto-rete. Questo comportamento è stato sfruttato dai <a href="/wiki/Cracker_(informatica)" title="Cracker (informatica)">cracker</a> per creare attacchi di tipo <i><a href="/wiki/Denial_of_service" title="Denial of service">denial of service</a></i>, pertanto è buona norma disabilitare nei router l'inoltro del broadcast diretto. </p> <div class="mw-heading mw-heading3"><h3 id="Indirizzamento_a_classi">Indirizzamento a classi</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=IPv4&veaction=edit&section=7" title="Modifica la sezione Indirizzamento a classi" class="mw-editsection-visualeditor"><span>modifica</span></a><span class="mw-editsection-divider"> | </span><a href="/w/index.php?title=IPv4&action=edit&section=7" title="Edit section's source code: Indirizzamento a classi"><span>modifica wikitesto</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r130657691">body:not(.skin-minerva) .mw-parser-output .vedi-anche{font-size:95%}</style><style data-mw-deduplicate="TemplateStyles:r139142988">.mw-parser-output .hatnote-content{align-items:center;display:flex}.mw-parser-output .hatnote-icon{flex-shrink:0}.mw-parser-output .hatnote-icon img{display:flex}.mw-parser-output .hatnote-text{font-style:italic}body:not(.skin-minerva) .mw-parser-output .hatnote{border:1px solid #CCC;display:flex;margin:.5em 0;padding:.2em .5em}body:not(.skin-minerva) .mw-parser-output .hatnote-text{padding-left:.5em}body.skin-minerva .mw-parser-output .hatnote-icon{padding-right:8px}body.skin-minerva .mw-parser-output .hatnote-icon img{height:auto;width:16px}body.skin--responsive .mw-parser-output .hatnote a.new{color:#d73333}body.skin--responsive .mw-parser-output .hatnote a.new:visited{color:#a55858}</style> <div class="hatnote noprint vedi-anche"> <div class="hatnote-content"><span class="noviewer hatnote-icon" typeof="mw:File"><span><img src="//upload.wikimedia.org/wikipedia/commons/thumb/8/87/Magnifying_glass_icon_mgx2.svg/18px-Magnifying_glass_icon_mgx2.svg.png" decoding="async" width="18" height="18" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/8/87/Magnifying_glass_icon_mgx2.svg/27px-Magnifying_glass_icon_mgx2.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/8/87/Magnifying_glass_icon_mgx2.svg/36px-Magnifying_glass_icon_mgx2.svg.png 2x" data-file-width="286" data-file-height="280" /></span></span> <span class="hatnote-text">Lo stesso argomento in dettaglio: <b><a href="/wiki/Classi_di_indirizzi_IP" title="Classi di indirizzi IP">Classi di indirizzi IP</a></b>.</span></div> </div> <p>Se un host deve comunicare con un altro host della stessa sottorete, userà il protocollo di livello 2 della rete a cui è collegato, altrimenti dovrà inviare i pacchetti ad un <a href="/wiki/Router" title="Router">gateway o router</a>, che sarà connesso ad altre reti e si occuperà di inoltrare i pacchetti ricevuti. </p><p>La comunicazione tra i router avviene mediante indirizzi IP utilizzando delle tecniche particolari di indirizzamento per individuare la sottorete e l'host. </p><p>Originariamente lo schema delle suddivisioni delle due componenti era a classi per cui un <a href="/wiki/Indirizzo_IP" title="Indirizzo IP">indirizzo IP</a> apparteneva una classe (<i>classfull</i>) in base ai primi <span class="nowrap"><span data-sort-value="7000400000000000000♠"></span>4 bit</span> dell'IP. </p><p>Con questo schema l'indirizzo è ad <a href="/w/index.php?title=Autoidentificazione&action=edit&redlink=1" class="new" title="Autoidentificazione (la pagina non esiste)">autoidentificazione</a> perché il confine tra le due componenti si può determinare con i bit più significativi. </p> <div class="mw-heading mw-heading3"><h3 id="Limiti">Limiti</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=IPv4&veaction=edit&section=8" title="Modifica la sezione Limiti" class="mw-editsection-visualeditor"><span>modifica</span></a><span class="mw-editsection-divider"> | </span><a href="/w/index.php?title=IPv4&action=edit&section=8" title="Edit section's source code: Limiti"><span>modifica wikitesto</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r130657691" /><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r139142988" /> <div class="hatnote noprint vedi-anche"> <div class="hatnote-content"><span class="noviewer hatnote-icon" typeof="mw:File"><span><img src="//upload.wikimedia.org/wikipedia/commons/thumb/8/87/Magnifying_glass_icon_mgx2.svg/18px-Magnifying_glass_icon_mgx2.svg.png" decoding="async" width="18" height="18" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/8/87/Magnifying_glass_icon_mgx2.svg/27px-Magnifying_glass_icon_mgx2.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/8/87/Magnifying_glass_icon_mgx2.svg/36px-Magnifying_glass_icon_mgx2.svg.png 2x" data-file-width="286" data-file-height="280" /></span></span> <span class="hatnote-text">Lo stesso argomento in dettaglio: <b><a href="/wiki/Saturazione_di_IPv4" title="Saturazione di IPv4">Saturazione di IPv4</a></b>.</span></div> </div> <p>Il numero di indirizzi univoci disponibili in IPv4 è <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}=256^{4}=4.294.967.296\cong 4,3\cdot 10^{9}}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <msup> <mn>2</mn> <mrow class="MJX-TeXAtom-ORD"> <mn>32</mn> </mrow> </msup> <mo>=</mo> <msup> <mn>256</mn> <mrow class="MJX-TeXAtom-ORD"> <mn>4</mn> </mrow> </msup> <mo>=</mo> <mn>4.294.967.296</mn> <mo>≅</mo> <mn>4</mn> <mo>,</mo> <mn>3</mn> <mo>⋅</mo> <msup> <mn>10</mn> <mrow class="MJX-TeXAtom-ORD"> <mn>9</mn> </mrow> </msup> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle 2^{32}=256^{4}=4.294.967.296\cong 4,3\cdot 10^{9}}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/e20880ebccdc62e21df56ed755865e18d6f5d6c6" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.671ex; width:38.858ex; height:3.009ex;" alt="{\displaystyle 2^{32}=256^{4}=4.294.967.296\cong 4,3\cdot 10^{9}}" /></span>, ma bisogna tener presente che non vengono usati tutti, perché alcuni sono riservati a un particolare utilizzo (ad esempio gli indirizzi <code>0.0.0.0</code>, <code><a href="/wiki/127.0.0.1" class="mw-redirect" title="127.0.0.1">127.0.0.1</a></code>, <code>255.255.255.255</code>, <code>192.0.34.166</code> e la classe <code>192.168.0.1/16</code>) e perché certe classi non vengono sfruttate interamente per via della suddivisione interna in classi più piccole. </p><p>L'indirizzamento a <a href="/wiki/Classi_di_indirizzi_IP" title="Classi di indirizzi IP">classi</a>, proprio per questo, presenta diversi limiti dovuti soprattutto al numero di host gestibili dalle diverse classi. </p><p>In pratica se si esauriscono gli indirizzi univoci resi disponibili da una classe, ad esempio la C connettendo più di 255 host, occorre fare ricorso ad un indirizzo di classe superiore. </p><p>Il cambiamento di indirizzo non è indolore con questa tecnica perché il software di rete va aggiornato con i nuovi indirizzi e non consente una transizione graduale. </p><p>In pratica l'indicatore di rete univoco non poteva adempiere alle esigenze della crescita che negli anni ottanta ebbero le reti <a href="/wiki/LAN" class="mw-redirect" title="LAN">LAN</a>. Quindi per risparmiare i prefissi di rete si dovettero escogitare altre tecniche come quella del mascheramento (vedi <a href="/wiki/Network_address_translation" title="Network address translation">NAT</a>) per continuare a fare in modo che IPv4 potesse adempiere al suo ruolo prima dell'entrata di <a href="/wiki/IPv6" title="IPv6">IPv6</a>. </p> <div class="mw-heading mw-heading3"><h3 id="Indirizzamento_senza_classi">Indirizzamento senza classi</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=IPv4&veaction=edit&section=9" title="Modifica la sezione Indirizzamento senza classi" class="mw-editsection-visualeditor"><span>modifica</span></a><span class="mw-editsection-divider"> | </span><a href="/w/index.php?title=IPv4&action=edit&section=9" title="Edit section's source code: Indirizzamento senza classi"><span>modifica wikitesto</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>L'indirizzamento in classi è considerato obsoleto e per permettere un migliore sfruttamento degli indirizzi IP disponibili, è stato introdotto l'indirizzamento senza classi (<i>classless</i>), o <a href="/wiki/CIDR" class="mw-redirect" title="CIDR">CIDR</a>. </p><p>La modifica introdotta dal CIDR consiste essenzialmente nell'utilizzare <a href="/wiki/Maschere_di_sottorete" class="mw-redirect" title="Maschere di sottorete">maschere di sottorete</a> di lunghezza arbitraria, mentre l'indirizzamento con classi ammetteva solo tre lunghezze della maschera di sottorete: <code>/8</code>, <code>/16</code> e <code>/24</code>. La maschera della vecchia classe C (<code>/24</code>) è ancora popolare, ma si usano anche maschere più corte per reti grandi (<code>/23</code> o <code>/22</code>) o più lunghe per reti piccole (<code>/25</code>, <code>/26</code>, fino a <code>/30</code> per reti punto-punto). </p><p>I bit che nella maschera di sottorete sono a 1 fanno parte dell'indirizzo della sottorete, gli altri sono l'indirizzo dell'host. Normalmente, la maschera di sottorete è costituita da <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 N}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mi>N</mi> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle N}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/f5e3890c981ae85503089652feb48b191b57aae3" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; width:2.064ex; height:2.176ex;" alt="{\displaystyle N}" /></span> bit a 1 seguiti da <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> bit a 0 e può essere abbreviata nella forma <code>/N</code>. </p><p>In questo modo non si è vincolati a un numero fisso di bit per determinare l'indirizzo di rete, ma i bit utili a rappresentare la rete, piuttosto che l'host, sono fissati liberamente. </p> <div class="mw-heading mw-heading3"><h3 id="Enti_di_gestione">Enti di gestione</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=IPv4&veaction=edit&section=10" title="Modifica la sezione Enti di gestione" class="mw-editsection-visualeditor"><span>modifica</span></a><span class="mw-editsection-divider"> | </span><a href="/w/index.php?title=IPv4&action=edit&section=10" title="Edit section's source code: Enti di gestione"><span>modifica wikitesto</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Gli indirizzi IP sono univoci a livello mondiale e vengono assegnati in modo centralizzato da una gerarchia di enti appositi. Sono considerati una risorsa preziosa da gestire con cura. Per rafforzare questo concetto, si parla di "indirizzi IP pubblici". </p><p>Inizialmente l'autorità preposta era la IANA (Internet Assigned Number Authority), dopo il 1998 venne creato l'<a href="/wiki/ICANN" title="ICANN">ICANN</a> (Internet corporation for Assigned Names and Numbers) che opera tuttora. Essa è responsabile della gestione degli indirizzi IP in base alle direttive dell'<a href="/wiki/Request_for_Comments" title="Request for Comments">RFC</a> 2050. </p> <div class="mw-heading mw-heading2"><h2 id="Note">Note</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=IPv4&veaction=edit&section=11" title="Modifica la sezione Note" class="mw-editsection-visualeditor"><span>modifica</span></a><span class="mw-editsection-divider"> | </span><a href="/w/index.php?title=IPv4&action=edit&section=11" title="Edit section's source code: Note"><span>modifica wikitesto</span></a><span class="mw-editsection-bracket">]</span></span></div> <div class="mw-references-wrap"><ol class="references"> <li id="cite_note-1"><a href="#cite_ref-1"><b>^</b></a> <span class="reference-text">(<span style="font-weight:bolder; font-size:80%"><abbr title="inglese">EN</abbr></span>) <a rel="nofollow" class="external text" href="http://bgp.potaroo.net/v6/v6rpt.html">IPv6: IPv6 / IPv4 Comparative Statistics</a></span> </li> </ol></div> <div class="mw-heading mw-heading2"><h2 id="Voci_correlate">Voci correlate</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=IPv4&veaction=edit&section=12" title="Modifica la sezione Voci correlate" class="mw-editsection-visualeditor"><span>modifica</span></a><span class="mw-editsection-divider"> | </span><a href="/w/index.php?title=IPv4&action=edit&section=12" title="Edit section's source code: Voci correlate"><span>modifica wikitesto</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a href="/wiki/Internet_Protocol" title="Internet Protocol">Internet Protocol</a></li> <li><a href="/wiki/IPv6" title="IPv6">IPv6</a></li> <li><a href="/wiki/Classi_di_indirizzi_IP" title="Classi di indirizzi IP">Classi di indirizzi IP</a></li> <li><a href="/wiki/Saturazione_di_IPv4" title="Saturazione di IPv4">Saturazione di IPv4</a></li> <li><a href="/wiki/Transizione_IPV4/IPV6" class="mw-redirect" title="Transizione IPV4/IPV6">Transizione IPV4/IPV6</a></li> <li><a href="/wiki/Indirizzo_di_broadcast" title="Indirizzo di broadcast">Indirizzo di broadcast</a></li></ul> <div class="mw-heading mw-heading2"><h2 id="Altri_progetti">Altri progetti</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=IPv4&veaction=edit&section=13" title="Modifica la sezione Altri progetti" class="mw-editsection-visualeditor"><span>modifica</span></a><span class="mw-editsection-divider"> | </span><a href="/w/index.php?title=IPv4&action=edit&section=13" title="Edit section's source code: Altri progetti"><span>modifica wikitesto</span></a><span class="mw-editsection-bracket">]</span></span></div> <div id="interProject" class="toccolours" style="display: none; clear: both; margin-top: 2em"><p id="sisterProjects" style="background-color: #efefef; color: black; font-weight: bold; margin: 0"><span>Altri progetti</span></p><ul title="Collegamenti verso gli altri progetti Wikimedia"> <li class="" title=""><a href="https://it.wikibooks.org/wiki/Internet:_architettura_e_protocolli/Protocollo_IPv4" class="extiw" title="b:Internet: architettura e protocolli/Protocollo IPv4">Wikibooks</a></li> <li class="" title=""><span class="plainlinks" title="commons:Category:IPv4"><a class="external text" href="https://commons.wikimedia.org/wiki/Category:IPv4?uselang=it">Wikimedia Commons</a></span></li></ul></div> <ul><li><span typeof="mw:File"><a href="https://it.wikibooks.org/wiki/" title="Collabora a Wikibooks"><img alt="Collabora a Wikibooks" src="//upload.wikimedia.org/wikipedia/commons/thumb/f/fa/Wikibooks-logo.svg/18px-Wikibooks-logo.svg.png" decoding="async" width="18" height="18" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/f/fa/Wikibooks-logo.svg/27px-Wikibooks-logo.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/f/fa/Wikibooks-logo.svg/36px-Wikibooks-logo.svg.png 2x" data-file-width="300" data-file-height="300" /></a></span> <a href="https://it.wikibooks.org/wiki/" class="extiw" title="b:">Wikibooks</a> contiene testi o manuali sull'<b><a href="https://it.wikibooks.org/wiki/Internet:_architettura_e_protocolli/Protocollo_IPv4" class="extiw" title="b:Internet: architettura e protocolli/Protocollo IPv4">IPv4</a></b></li> <li><span typeof="mw:File"><a href="https://commons.wikimedia.org/wiki/?uselang=it" title="Collabora a Wikimedia Commons"><img alt="Collabora a Wikimedia Commons" src="//upload.wikimedia.org/wikipedia/commons/thumb/4/4a/Commons-logo.svg/20px-Commons-logo.svg.png" decoding="async" width="18" height="24" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/4/4a/Commons-logo.svg/40px-Commons-logo.svg.png 1.5x" data-file-width="1024" data-file-height="1376" /></a></span> <span class="plainlinks"><a class="external text" href="https://commons.wikimedia.org/wiki/?uselang=it">Wikimedia Commons</a></span> contiene immagini o altri file sull'<b><span class="plainlinks"><a class="external text" href="https://commons.wikimedia.org/wiki/Category:IPv4?uselang=it">IPv4</a></span></b></li></ul> <div class="mw-heading mw-heading2"><h2 id="Collegamenti_esterni">Collegamenti esterni</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=IPv4&veaction=edit&section=14" title="Modifica la sezione Collegamenti esterni" class="mw-editsection-visualeditor"><span>modifica</span></a><span class="mw-editsection-divider"> | </span><a href="/w/index.php?title=IPv4&action=edit&section=14" title="Edit section's source code: Collegamenti esterni"><span>modifica wikitesto</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li class="mw-empty-elt"></li> <li><cite id="CITEREFSapere.it" class="citation web" style="font-style:normal"> <a rel="nofollow" class="external text" href="https://www.sapere.it/enciclopedia/IPv4.html"><span style="font-style:italic;">IPv4</span></a>, su <span style="font-style:italic;">sapere.it</span>, <a href="/wiki/De_Agostini" title="De Agostini">De Agostini</a>.</cite> <span class="mw-valign-text-top noprint" typeof="mw:File/Frameless"><a href="https://www.wikidata.org/wiki/Q11103#P6706" title="Modifica su Wikidata"><img alt="Modifica su Wikidata" src="//upload.wikimedia.org/wikipedia/commons/thumb/7/73/Blue_pencil.svg/20px-Blue_pencil.svg.png" decoding="async" width="10" height="10" class="mw-file-element" data-file-width="600" data-file-height="600" /></a></span></li> <li><cite id="CITEREFFOLDOC" class="citation testo" style="font-style:normal">(<span style="font-weight:bolder; font-size:80%"><abbr title="inglese">EN</abbr></span>) Denis Howe, <span style="font-style:italic;"><a href="https://foldoc.org/Internet_Protocol_version_4" class="extiw" title="foldoc:Internet Protocol version 4">Internet Protocol version 4</a></span>, in <span style="font-style:italic;"><a href="/wiki/Free_On-line_Dictionary_of_Computing" title="Free On-line Dictionary of Computing">Free On-line Dictionary of Computing</a></span>.</cite> Disponibile con licenza <a href="/wiki/GNU_Free_Documentation_License" title="GNU Free Documentation License">GFDL</a></li> <li><cite class="citation web" style="font-style:normal">(<span style="font-weight:bolder; font-size:80%"><abbr title="inglese">EN</abbr></span>) <a rel="nofollow" class="external text" href="https://web.archive.org/web/20041204053255/http://www.ietf.org/rfc/rfc0791.txt"><span style="font-style:italic;">RFC 791 - Internet Protocol</span></a> (<span style="font-weight: bolder; font-size:80%"><abbr title="documento di puro testo">TXT</abbr></span>), su <span style="font-style:italic;">ietf.org</span>. <small>URL consultato il 19 giugno 2007</small> <small>(archiviato dall'<abbr title="https://www.ietf.org/rfc/rfc0791.txt">url originale</abbr> il 4 dicembre 2004)</small>.</cite></li> <li><cite class="citation web" style="font-style:normal">(<span style="font-weight:bolder; font-size:80%"><abbr title="inglese">EN</abbr></span>) <a rel="nofollow" class="external text" href="https://tools.ietf.org/html/rfc3168"><span style="font-style:italic;">RFC 3168 - Explicit congestion notification</span></a>, su <span style="font-style:italic;">tools.ietf.org</span>.</cite></li> <li><cite class="citation web" style="font-style:normal">(<span style="font-weight:bolder; font-size:80%"><abbr title="inglese">EN</abbr></span>) <a rel="nofollow" class="external text" href="https://www.ietf.org/rfc/rfc2050.txt"><span style="font-style:italic;">RFC 2050 - Internet Registry IP Allocation Guidelines</span></a> (<span style="font-weight: bolder; font-size:80%"><abbr title="documento di puro testo">TXT</abbr></span>), su <span style="font-style:italic;">ietf.org</span>.</cite></li></ul> <style data-mw-deduplicate="TemplateStyles:r141815314">.mw-parser-output .navbox{border:1px solid #aaa;clear:both;margin:auto;padding:2px;width:100%}.mw-parser-output .navbox th{padding-left:1em;padding-right:1em;text-align:center}.mw-parser-output .navbox>tbody>tr:first-child>th{background:#ccf;font-size:90%;width:100%;color:var(--color-base,black)}.mw-parser-output .navbox_navbar{float:left;margin:0;padding:0 10px 0 0;text-align:left;width:6em}.mw-parser-output .navbox_title{font-size:110%}.mw-parser-output .navbox_abovebelow{background:#ddf;font-size:90%;font-weight:normal}.mw-parser-output .navbox_group{background:#ddf;font-size:90%;padding:0 10px;white-space:nowrap}.mw-parser-output .navbox_list{font-size:90%;width:100%}.mw-parser-output .navbox_list a{white-space:nowrap}html:not(.vector-feature-night-mode-enabled) .mw-parser-output .navbox_odd{background:#fdfdfd;color:var(--color-base,black)}html:not(.vector-feature-night-mode-enabled) .mw-parser-output .navbox_even{background:#f7f7f7;color:var(--color-base,black)}.mw-parser-output .navbox a.mw-selflink{color:var(--color-base,black)}.mw-parser-output .navbox_center{text-align:center}.mw-parser-output .navbox .navbox_image{padding-left:7px;vertical-align:middle;width:0}.mw-parser-output .navbox+.navbox{margin-top:-1px}.mw-parser-output .navbox .mw-collapsible-toggle{font-weight:normal;text-align:right;width:7em}body.skin--responsive .mw-parser-output .navbox_image img{max-width:none!important}.mw-parser-output .subnavbox{margin:-3px;width:100%}.mw-parser-output .subnavbox_group{background:#e6e6ff;padding:0 10px}@media screen{html.skin-theme-clientpref-night .mw-parser-output .navbox>tbody>tr:first-child>th{background:var(--background-color-interactive)!important}html.skin-theme-clientpref-night .mw-parser-output .navbox th{color:var(--color-base)!important}html.skin-theme-clientpref-night .mw-parser-output .navbox_abovebelow,html.skin-theme-clientpref-night .mw-parser-output .navbox_group{background:var(--background-color-interactive-subtle)!important}html.skin-theme-clientpref-night .mw-parser-output .subnavbox_group{background:var(--background-color-neutral-subtle)!important}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .navbox>tbody>tr:first-child>th{background:var(--background-color-interactive)!important}html.skin-theme-clientpref-os .mw-parser-output .navbox th{color:var(--color-base)!important}html.skin-theme-clientpref-os .mw-parser-output .navbox_abovebelow,html.skin-theme-clientpref-os .mw-parser-output .navbox_group{background:var(--background-color-interactive-subtle)!important}html.skin-theme-clientpref-os .mw-parser-output .subnavbox_group{background:var(--background-color-neutral-subtle)!important}}</style><table class="navbox mw-collapsible mw-collapsed noprint metadata" id="navbox-Suite_di_protocolli_Internet"><tbody><tr><th colspan="2"><div class="navbox_navbar"><div class="noprint plainlinks" style="background-color:transparent; padding:0; font-size:xx-small; color:var(--color-base, #000000); white-space:nowrap;"><a href="/wiki/Template:Suite_di_protocolli_Internet" title="Template:Suite di protocolli Internet"><span title="Vai alla pagina del template">V</span></a> · <a href="/wiki/Discussioni_template:Suite_di_protocolli_Internet" title="Discussioni template:Suite di protocolli Internet"><span title="Discuti del template">D</span></a> · <a class="external text" href="https://it.wikipedia.org/w/index.php?title=Template:Suite_di_protocolli_Internet&action=edit"><span title="Modifica il template. Usa l'anteprima prima di salvare">M</span></a></div></div><span class="navbox_title"><a href="/wiki/Suite_di_protocolli_Internet" title="Suite di protocolli Internet">Suite di protocolli Internet</a></span></th></tr><tr><th colspan="1" class="navbox_group"><a href="/wiki/Livello_di_applicazione" title="Livello di applicazione">Livello di applicazione</a></th><td colspan="1" class="navbox_list navbox_odd"><a href="/wiki/File_Transfer_Protocol" title="File Transfer Protocol">FTP</a><b> ·</b> <a href="/wiki/Hypertext_Transfer_Protocol" title="Hypertext Transfer Protocol">HTTP</a><b> ·</b> <a href="/wiki/HTTP/2" title="HTTP/2">HTTP/2</a><b> ·</b> <a href="/wiki/HTTP/3" title="HTTP/3">HTTP/3</a><b> ·</b> <a href="/wiki/HTTPS" title="HTTPS">HTTPS</a><b> ·</b> <a href="/wiki/Network_News_Transfer_Protocol" title="Network News Transfer Protocol">NNTP</a><b> ·</b> <a href="/wiki/Dynamic_Host_Configuration_Protocol" title="Dynamic Host Configuration Protocol">DHCP</a><b> ·</b> <a href="/wiki/Domain_Name_System" title="Domain Name System">DNS</a><b> ·</b> <a href="/wiki/Simple_Mail_Transfer_Protocol" title="Simple Mail Transfer Protocol">SMTP</a><b> ·</b> <a href="/wiki/Post_Office_Protocol" title="Post Office Protocol">POP3</a><b> ·</b> <a href="/wiki/Internet_Message_Access_Protocol" title="Internet Message Access Protocol">IMAP</a><b> ·</b> <a href="/wiki/Telnet" title="Telnet">Telnet</a><b> ·</b> <a href="/wiki/Secure_Shell" title="Secure Shell">SSH</a><b> ·</b> <a href="/wiki/SSH_File_Transfer_Protocol" title="SSH File Transfer Protocol">SFTP</a><b> ·</b> <a href="/wiki/Trivial_File_Transfer_Protocol" title="Trivial File Transfer Protocol">TFTP</a><b> ·</b> <a href="/wiki/Internet_Relay_Chat" title="Internet Relay Chat">IRC</a><b> ·</b> <a href="/wiki/Simple_Network_Management_Protocol" title="Simple Network Management Protocol">SNMP</a><b> ·</b> <a href="/wiki/Voice_over_IP" title="Voice over IP">VoIP</a><b> ·</b> <a href="/wiki/Session_Initiation_Protocol" title="Session Initiation Protocol">SIP</a><b> ·</b> <a href="/wiki/Real-time_Transport_Protocol" title="Real-time Transport Protocol">RTP</a><b> ·</b> <a href="/wiki/Real_Time_Streaming_Protocol" title="Real Time Streaming Protocol">RTSP</a><b> ·</b> <a href="/wiki/Rsync" title="Rsync">Rsync</a><b> ·</b> <a href="/wiki/Hot_Standby_Router_Protocol" title="Hot Standby Router Protocol">HSRP</a><b> ·</b> <a href="/wiki/Routing_Information_Protocol" title="Routing Information Protocol">RIP</a><b> ·</b> <a href="/wiki/Border_Gateway_Protocol" title="Border Gateway Protocol">BGP</a><b> ·</b> <a href="/wiki/Interior_Gateway_Routing_Protocol" title="Interior Gateway Routing Protocol">IGRP</a><b> ·</b> <a href="/wiki/Categoria:Protocolli_livello_applicazione" title="Categoria:Protocolli livello applicazione"><i>altro..</i></a></td></tr><tr><th colspan="1" class="navbox_group"><a href="/wiki/Livello_di_trasporto" title="Livello di trasporto">Livello di trasporto</a></th><td colspan="1" class="navbox_list navbox_even"><a href="/wiki/Transmission_Control_Protocol" title="Transmission Control Protocol">TCP</a><b> ·</b> <a href="/wiki/User_Datagram_Protocol" title="User Datagram Protocol">UDP</a><b> ·</b> <a href="/wiki/Stream_Control_Transmission_Protocol" title="Stream Control Transmission Protocol">SCTP</a><b> ·</b> <a href="/wiki/Datagram_Congestion_Control_Protocol" title="Datagram Congestion Control Protocol">DCCP</a><b> ·</b> <a href="/wiki/Categoria:Protocolli_livello_trasporto" title="Categoria:Protocolli livello trasporto"><i>altro..</i></a></td></tr><tr><th colspan="1" class="navbox_group"><a href="/wiki/Livello_di_rete" title="Livello di rete">Livello di rete</a></th><td colspan="1" class="navbox_list navbox_odd"><a href="/wiki/Internet_Protocol" title="Internet Protocol">IP</a> (<a class="mw-selflink selflink">IPv4</a><b> ·</b> <a href="/wiki/IPv6" title="IPv6">IPv6</a>)<b> ·</b> <a href="/wiki/Internet_Control_Message_Protocol" title="Internet Control Message Protocol">ICMP</a> (<a href="/wiki/ICMPv6" title="ICMPv6">ICMPv6</a>)<b> ·</b> <a href="/wiki/Internet_Group_Management_Protocol" title="Internet Group Management Protocol">IGMP</a><b> ·</b> <a href="/wiki/IPsec" title="IPsec">IPsec</a><b> ·</b> <a href="/wiki/Open_Shortest_Path_First" title="Open Shortest Path First">OSPF</a><b> ·</b> <a href="/wiki/Categoria:Protocolli_livello_rete" title="Categoria:Protocolli livello rete"><i>altro..</i></a></td></tr><tr><th colspan="1" class="navbox_group"><a href="/wiki/Livello_di_accesso_alla_rete" title="Livello di accesso alla rete">Livello di accesso alla rete</a> (<a href="/wiki/Logical_link_control" title="Logical link control">LLC</a> <b> ·</b> <a href="/wiki/Media_Access_Control" title="Media Access Control">MAC</a>)</th><td colspan="1" class="navbox_list navbox_even"><a href="/wiki/Address_Resolution_Protocol" title="Address Resolution Protocol">ARP</a><b> ·</b> <a href="/wiki/Reverse_Address_Resolution_Protocol" title="Reverse Address Resolution Protocol">RARP</a><b> ·</b> <a href="/wiki/Neighbor_Discovery_Protocol" title="Neighbor Discovery Protocol">NDP</a><b> ·</b> <a href="/wiki/Point-to-Point_Protocol" title="Point-to-Point Protocol">PPP</a><b> ·</b> <a href="/wiki/Serial_Line_Internet_Protocol" title="Serial Line Internet Protocol">SLIP</a><b> ·</b> <a href="/wiki/Ethernet" title="Ethernet">Ethernet</a><b> ·</b> <a href="/wiki/Token_ring" title="Token ring">Token ring</a><b> ·</b> <a href="/wiki/Token_bus" title="Token bus">Token bus</a><b> ·</b> <a href="/wiki/Wi-Fi" title="Wi-Fi">WiFi</a><b> ·</b> <a href="/wiki/Powerline" title="Powerline">Powerline</a><b> ·</b> <a href="/wiki/Asynchronous_Transfer_Mode" title="Asynchronous Transfer Mode">ATM</a><b> ·</b> <a href="/wiki/IEEE_802.1aq" title="IEEE 802.1aq">SPB</a><b> ·</b> <a href="/wiki/Multiprotocol_Label_Switching" title="Multiprotocol Label Switching">MPLS</a><b> ·</b> <a href="/wiki/Fiber_distributed_data_interface" title="Fiber distributed data interface">FDDI</a><b> ·</b> <a href="/wiki/High-Speed_Downlink_Packet_Access" title="High-Speed Downlink Packet Access">HSDPA</a><b> ·</b> <a href="/wiki/WiMAX" title="WiMAX">WiMAX</a><b> ·</b> <a href="/wiki/Categoria:Protocolli_livello_collegamento" title="Categoria:Protocolli livello collegamento"><i>altro..</i></a></td></tr></tbody></table> <style data-mw-deduplicate="TemplateStyles:r140554510">.mw-parser-output .CdA{border:1px solid #aaa;width:100%;margin:auto;font-size:90%;padding:2px}.mw-parser-output .CdA th{background-color:#f2f2f2;font-weight:bold;width:20%}@media screen{html.skin-theme-clientpref-night .mw-parser-output .CdA{border-color:#54595D}html.skin-theme-clientpref-night .mw-parser-output .CdA th{background-color:#202122}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output 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srcset="//upload.wikimedia.org/wikipedia/commons/thumb/4/46/Crystal_128_displayphone.png/60px-Crystal_128_displayphone.png 2x" data-file-width="124" data-file-height="127" /></a></span> <b><a href="/wiki/Portale:Telematica" title="Portale:Telematica">Portale Telematica</a></b>: accedi alle voci di Wikipedia che parlano di reti, telecomunicazioni e protocolli di rete</div></div></div>    </div><noscript><img src="https://auth.wikimedia.org/loginwiki/wiki/Special:CentralAutoLogin/start?useformat=desktop&type=1x1&usesul3=1" alt="" width="1" height="1" style="border: none; position: absolute;"></noscript> <div class="printfooter" data-nosnippet="">Estratto da "<a dir="ltr" href="https://it.wikipedia.org/w/index.php?title=IPv4&oldid=143518487">https://it.wikipedia.org/w/index.php?title=IPv4&oldid=143518487</a>"</div></div> <div id="catlinks" class="catlinks" data-mw="interface"><div id="mw-normal-catlinks" class="mw-normal-catlinks"><a href="/wiki/Categoria:Categorie" 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controllo di autorità</a></li><li><a href="/wiki/Categoria:Pagine_che_utilizzano_collegamenti_magici_RFC" title="Categoria:Pagine che utilizzano collegamenti magici RFC">Pagine che utilizzano collegamenti magici RFC</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"> Questa pagina è stata modificata per l'ultima volta il 10 feb 2025 alle 10:04.</li> <li id="footer-info-copyright">Il testo è disponibile secondo la <a rel="nofollow" class="external text" href="https://creativecommons.org/licenses/by-sa/4.0/deed.it">licenza Creative Commons Attribuzione-Condividi allo stesso modo</a>; possono applicarsi condizioni ulteriori. 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