{"id":1546,"date":"2025-06-25T18:10:40","date_gmt":"2025-06-25T17:10:40","guid":{"rendered":"https:\/\/workboot.fr\/ciela\/?page_id=1546"},"modified":"2025-06-25T18:26:58","modified_gmt":"2025-06-25T17:26:58","slug":"les-classes-ipv4","status":"publish","type":"page","link":"https:\/\/workboot.fr\/ciela\/les-classes-ipv4\/","title":{"rendered":"Les Classes (IPV4)"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">En r\u00e9seau, quand on parle de <strong>classes<\/strong>, on fait r\u00e9f\u00e9rence \u00e0 un ancien syst\u00e8me de <strong>classement des adresses IPv4<\/strong> en plusieurs <strong>cat\u00e9gories<\/strong> (classes A, B, C, D, E). C\u2019\u00e9tait utilis\u00e9 au d\u00e9but d\u2019Internet pour simplifier l\u2019attribution des adresses IP, mais cela reste <strong>important pour comprendre le fonctionnement des adresses IP et du subnetting<\/strong>.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">\ud83e\uddee Une adresse IPv4, c\u2019est quoi ?<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Format : <code>X.X.X.X<\/code> (ex : <code>192.168.1.1<\/code>)<\/li>\n\n\n\n<li>32 bits \u2192 divis\u00e9e en <strong>4 octets<\/strong> (8 bits chacun)<\/li>\n\n\n\n<li>Il y a <strong>2 parties<\/strong> :\n<ul class=\"wp-block-list\">\n<li><strong>Identifiant r\u00e9seau<\/strong> (<em>Network ID<\/em>)<\/li>\n\n\n\n<li><strong>Identifiant h\u00f4te<\/strong> (<em>Host ID<\/em>)<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">\ud83d\udce6 Les classes d\u2019adresses IPv4 (A, B, C)<\/h2>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>Classe<\/th><th>Octet de d\u00e9but (1er)<\/th><th>Plage d\u2019adresses<\/th><th>Bits r\u00e9seau<\/th><th>Bits h\u00f4tes<\/th><th>Nombre d\u2019h\u00f4tes<\/th><th>Exemple<\/th><\/tr><\/thead><tbody><tr><td>A<\/td><td>1 \u00e0 126<\/td><td><code>1.0.0.0<\/code> \u00e0 <code>126.255.255.255<\/code><\/td><td>8<\/td><td>24<\/td><td>~16 millions<\/td><td><code>10.0.0.1<\/code><\/td><\/tr><tr><td>B<\/td><td>128 \u00e0 191<\/td><td><code>128.0.0.0<\/code> \u00e0 <code>191.255.255.255<\/code><\/td><td>16<\/td><td>16<\/td><td>~65 000<\/td><td><code>172.16.0.1<\/code><\/td><\/tr><tr><td>C<\/td><td>192 \u00e0 223<\/td><td><code>192.0.0.0<\/code> \u00e0 <code>223.255.255.255<\/code><\/td><td>24<\/td><td>8<\/td><td>254<\/td><td><code>192.168.1.1<\/code><\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">\ud83d\udce1 Et les autres classes ?<\/h2>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>Classe<\/th><th>Usage<\/th><th>Plage d\u2019adresses<\/th><\/tr><\/thead><tbody><tr><td>D<\/td><td>Multidiffusion (multicast)<\/td><td><code>224.0.0.0<\/code> \u00e0 <code>239.255.255.255<\/code><\/td><\/tr><tr><td>E<\/td><td>R\u00e9serv\u00e9e (exp\u00e9rimental)<\/td><td><code>240.0.0.0<\/code> \u00e0 <code>255.255.255.255<\/code><\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">\ud83d\udd10 Adresses <strong>priv\u00e9es<\/strong> par classe (non rout\u00e9es sur Internet)<\/h2>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>Classe<\/th><th>Plage priv\u00e9e<\/th><th>Usage typique<\/th><\/tr><\/thead><tbody><tr><td>A<\/td><td><code>10.0.0.0<\/code> \u00e0 <code>10.255.255.255<\/code><\/td><td>R\u00e9seaux internes tr\u00e8s grands<\/td><\/tr><tr><td>B<\/td><td><code>172.16.0.0<\/code> \u00e0 <code>172.31.255.255<\/code><\/td><td>R\u00e9seaux d\u2019entreprise<\/td><\/tr><tr><td>C<\/td><td><code>192.168.0.0<\/code> \u00e0 <code>192.168.255.255<\/code><\/td><td>R\u00e9seaux domestiques (Wi-Fi, box)<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">\ud83c\udfaf Exemple concret :<\/h2>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\">Si ton PC a une IP comme <code>192.168.1.10<\/code>, c\u2019est :<\/p>\n<\/blockquote>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Une <strong>adresse priv\u00e9e<\/strong><\/li>\n\n\n\n<li>De <strong>classe C<\/strong><\/li>\n\n\n\n<li>Utilis\u00e9e sur un r\u00e9seau local (LAN)<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">\ud83e\udde0 \u00c0 retenir :<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Le syst\u00e8me par classes est <strong>d\u00e9suet<\/strong> (remplac\u00e9 par <strong>le CIDR \/ le subnetting<\/strong>), mais reste utile pour :\n<ul class=\"wp-block-list\">\n<li>comprendre comment l\u2019adressage fonctionne<\/li>\n\n\n\n<li>bien d\u00e9marrer avec les notions de r\u00e9seau<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li>Aujourd\u2019hui, on utilise des <strong>masques de sous-r\u00e9seau (\/24, \/16&#8230;)<\/strong> plus flexibles<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><a href=\"https:\/\/workboot.fr\/ciela\/les-classes\/\" data-type=\"page\" data-id=\"1549\">TD : sur les classes IPV4<\/a><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>\n","protected":false},"excerpt":{"rendered":"<p>En r\u00e9seau, quand on parle de classes, on fait r\u00e9f\u00e9rence \u00e0 un ancien syst\u00e8me de classement des adresses IPv4 en plusieurs cat\u00e9gories (classes A, B, C, D, E). C\u2019\u00e9tait utilis\u00e9 au d\u00e9but d\u2019Internet pour simplifier l\u2019attribution des adresses IP, mais cela reste important pour comprendre le fonctionnement des adresses IP et du subnetting. \ud83e\uddee Une [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_uag_custom_page_level_css":"","footnotes":""},"class_list":["post-1546","page","type-page","status-publish","hentry"],"uagb_featured_image_src":{"full":false,"thumbnail":false,"medium":false,"medium_large":false,"large":false,"1536x1536":false,"2048x2048":false},"uagb_author_info":{"display_name":"admin","author_link":"https:\/\/workboot.fr\/ciela\/author\/admin\/"},"uagb_comment_info":0,"uagb_excerpt":"En r\u00e9seau, quand on parle de classes, on fait r\u00e9f\u00e9rence \u00e0 un ancien syst\u00e8me de classement des adresses IPv4 en plusieurs cat\u00e9gories (classes A, B, C, D, E). C\u2019\u00e9tait utilis\u00e9 au d\u00e9but d\u2019Internet pour simplifier l\u2019attribution des adresses IP, mais cela reste important pour comprendre le fonctionnement des adresses IP et du subnetting. \ud83e\uddee Une\u2026","_links":{"self":[{"href":"https:\/\/workboot.fr\/ciela\/wp-json\/wp\/v2\/pages\/1546","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/workboot.fr\/ciela\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/workboot.fr\/ciela\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/workboot.fr\/ciela\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/workboot.fr\/ciela\/wp-json\/wp\/v2\/comments?post=1546"}],"version-history":[{"count":4,"href":"https:\/\/workboot.fr\/ciela\/wp-json\/wp\/v2\/pages\/1546\/revisions"}],"predecessor-version":[{"id":1562,"href":"https:\/\/workboot.fr\/ciela\/wp-json\/wp\/v2\/pages\/1546\/revisions\/1562"}],"wp:attachment":[{"href":"https:\/\/workboot.fr\/ciela\/wp-json\/wp\/v2\/media?parent=1546"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}