{"id":14,"date":"2026-09-18T06:03:52","date_gmt":"2026-09-17T21:03:52","guid":{"rendered":"https:\/\/www.theipv6portal.org\/column\/ipv4-exhaustion-ipv6-subnet\/"},"modified":"2026-09-18T16:13:04","modified_gmt":"2026-09-18T07:13:04","slug":"ipv4-exhaustion-ipv6-subnet","status":"publish","type":"post","link":"https:\/\/www.theipv6portal.org\/column\/ipv4-exhaustion-ipv6-subnet\/","title":{"rendered":"IPv4\u67af\u6e07\u3068IPv6 \u2014 \u30a2\u30c9\u30ec\u30b9\u8868\u8a18\u3068\u30b5\u30d6\u30cd\u30c3\u30c8\u306e\u57fa\u672c"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">\u300cIPv4\u30a2\u30c9\u30ec\u30b9\u304c\u67af\u6e07\u3057\u305f\u300d\u3068\u3044\u3046\u8a71\u306f\u4f55\u5e74\u3082\u524d\u304b\u3089\u805e\u304d\u307e\u3059\u304c\u3001\u5b9f\u52d9\u3067\u56f0\u308b\u306e\u306f<strong>IPv6\u306e\u8868\u8a18\u30eb\u30fc\u30eb\u3068\u30b5\u30d6\u30cd\u30c3\u30c8\u306e\u6570\u3048\u65b9<\/strong>\u3067\u3059\u3002\u3053\u3053\u3092\u62bc\u3055\u3048\u308b\u3068\u3001\u30b5\u30fc\u30d0\u30fc\u8a2d\u5b9a\u3084\u30d5\u30a1\u30a4\u30a2\u30a6\u30a9\u30fc\u30eb\u306e\u30eb\u30fc\u30eb\u8a18\u8ff0\u3067\u8ff7\u308f\u306a\u304f\u306a\u308a\u307e\u3059\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">IPv4\u306f\u7d0443\u5104\u500b\u3057\u304b\u306a\u3044<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">IPv4\u30a2\u30c9\u30ec\u30b9\u306f32\u30d3\u30c3\u30c8\u3001\u3064\u307e\u308a2\u306e32\u4e57\uff1d\u7d0443\u5104\u500b\u3067\u3059\u3002\u4e16\u754c\u4eba\u53e3\u3088\u308a\u5c11\u306a\u304f\u30011\u4eba\u304c\u8907\u6570\u306e\u7aef\u672b\u3092\u6301\u3064\u73fe\u5728\u3067\u306f\u5230\u5e95\u8db3\u308a\u307e\u305b\u3093\u3002\u65e5\u672c\u3092\u542b\u3080\u5404\u5730\u57df\u306e\u30ec\u30b8\u30b9\u30c8\u30ea\u3067\u306f<strong>\u3059\u3067\u306b\u65b0\u898f\u306e\u5927\u53e3\u5272\u308a\u5f53\u3066\u306f\u7d42\u4e86<\/strong>\u3057\u3066\u304a\u308a\u3001\u73fe\u5728\u306fNAT\uff08\u30a2\u30c9\u30ec\u30b9\u5909\u63db\uff09\u3068\u79fb\u8ee2\u5e02\u5834\u3067\u56de\u3063\u3066\u3044\u308b\u72b6\u614b\u3067\u3059\u3002<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" width=\"1000\" height=\"620\" src=\"https:\/\/www.theipv6portal.org\/column\/wp-content\/uploads\/2026\/09\/fig-ipv6.png\" alt=\"IPv4\uff0832\u30d3\u30c3\u30c8\u30fb\u7d0443\u5104\u500b\uff09\u3068IPv6\uff08128\u30d3\u30c3\u30c8\u30fb\u7d043.4\u00d710\u306e38\u4e57\u500b\uff09\u306e\u8868\u8a18\u306e\u9055\u3044\u3068\u3001CIDR\u8868\u8a18\u306b\u304a\u3051\u308b\u30cd\u30c3\u30c8\u30ef\u30fc\u30af\u90e8\u30fb\u30db\u30b9\u30c8\u90e8\u306e\u56f3\u89e3\" class=\"wp-image-10\" srcset=\"https:\/\/www.theipv6portal.org\/column\/wp-content\/uploads\/2026\/09\/fig-ipv6.png 1000w, https:\/\/www.theipv6portal.org\/column\/wp-content\/uploads\/2026\/09\/fig-ipv6-300x186.png 300w, https:\/\/www.theipv6portal.org\/column\/wp-content\/uploads\/2026\/09\/fig-ipv6-768x476.png 768w\" sizes=\"(max-width: 1000px) 100vw, 1000px\" \/><figcaption class=\"wp-element-caption\">IPv4\u3068IPv6\u306e\u8868\u8a18\u306e\u9055\u3044\u3068\u3001CIDR\u8868\u8a18\u306e\u8aad\u307f\u65b9<\/figcaption><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">IPv6\u306e\u8868\u8a18\u30eb\u30fc\u30eb3\u3064<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">IPv6\u306f128\u30d3\u30c3\u30c8\u309216\u9032\u65704\u6841\u00d78\u7d44\u3067\u8868\u3057\u307e\u3059\u3002\u9577\u3044\u306e\u3067\u3001\u6b21\u306e\u7701\u7565\u30eb\u30fc\u30eb\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u5404\u7d44\u306e\u5148\u982d\u306e0\u306f\u7701\u7565\u3067\u304d\u308b<\/strong>\uff1a<code>0db8<\/code> \u2192 <code>db8<\/code><\/li>\n<li><strong>\u9023\u7d9a\u3059\u308b0\u306e\u7d44\u306f\u300c::\u300d\u3067\u307e\u3068\u3081\u3089\u308c\u308b<\/strong>\uff1a<code>2001:db8:0:0:0:0:0:1<\/code> \u2192 <code>2001:db8::1<\/code><\/li>\n<li><strong>\u300c::\u300d\u306f1\u3064\u306e\u30a2\u30c9\u30ec\u30b9\u306b1\u56de\u3060\u3051<\/strong>\uff1a2\u56de\u4f7f\u3046\u3068\u5fa9\u5143\u3067\u304d\u306a\u304f\u306a\u308b\u305f\u3081\u7981\u6b62<\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\">\u30ed\u30b0\u306e\u7a81\u304d\u5408\u308f\u305b\u3067\u300c\u540c\u3058\u30a2\u30c9\u30ec\u30b9\u306a\u306e\u306b\u6587\u5b57\u5217\u304c\u4e00\u81f4\u3057\u306a\u3044\u300d\u3068\u3044\u3046\u4e8b\u6545\u306f\u3001\u3053\u306e\u7701\u7565\u5f62\u3068\u5b8c\u5168\u5f62\u304c\u6df7\u5728\u3059\u308b\u3053\u3068\u3067\u8d77\u3053\u308a\u307e\u3059\u3002\u6bd4\u8f03\u3059\u308b\u3068\u304d\u306f<strong>\u3069\u3061\u3089\u304b\u306e\u5f62\u306b\u6b63\u898f\u5316\u3057\u3066\u304b\u3089<\/strong>\u6271\u3046\u306e\u304c\u5b89\u5168\u3067\u3059\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">CIDR\u8868\u8a18\u300c\/24\u300d\u306f\u4f55\u3092\u610f\u5473\u3059\u308b\u304b<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\"><code>192.0.2.0\/24<\/code> \u306e\u300c\/24\u300d\u306f\u3001<strong>\u5148\u982d24\u30d3\u30c3\u30c8\u304c\u30cd\u30c3\u30c8\u30ef\u30fc\u30af\u90e8<\/strong>\u3068\u3044\u3046\u610f\u5473\u3067\u3059\u3002\u6b8b\u308a\u306e8\u30d3\u30c3\u30c8\u304c\u30db\u30b9\u30c8\u90e8\u306b\u306a\u308a\u3001\u305d\u306e\u30cd\u30c3\u30c8\u30ef\u30fc\u30af\u5185\u3067\u4f7f\u3048\u308b\u30a2\u30c9\u30ec\u30b9\u306e\u7bc4\u56f2\u3092\u6c7a\u3081\u307e\u3059\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u30cd\u30c3\u30c8\u30ef\u30fc\u30af\u30a2\u30c9\u30ec\u30b9\uff1a<code>192.0.2.0<\/code>\uff08\u30db\u30b9\u30c8\u90e8\u304c\u5168\u30660\uff09<\/li>\n<li>\u30d6\u30ed\u30fc\u30c9\u30ad\u30e3\u30b9\u30c8\u30a2\u30c9\u30ec\u30b9\uff1a<code>192.0.2.255<\/code>\uff08\u30db\u30b9\u30c8\u90e8\u304c\u5168\u30661\uff09<\/li>\n<li>\u5b9f\u969b\u306b\u6a5f\u5668\u3078\u5272\u308a\u5f53\u3066\u3089\u308c\u308b\u306e\u306f <code>192.0.2.1<\/code>\u301c<code>192.0.2.254<\/code> \u306e<strong>254\u500b<\/strong><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u300c\/25\u306b\u3059\u308b\u3068\u4f55\u53f0\u3064\u306a\u304c\u308b\u306e\u304b\u300d\u300c2\u3064\u306e\u30cd\u30c3\u30c8\u30ef\u30fc\u30af\u306b\u5206\u5272\u3057\u305f\u3044\u300d\u3068\u3044\u3063\u305f\u8a08\u7b97\u306f\u624b\u3067\u3084\u308b\u3068\u9593\u9055\u3048\u3084\u3059\u3044\u3068\u3053\u308d\u3067\u3059\u3002<a href=\"https:\/\/www.theipv6portal.org\/subnetcalc\" target=\"_blank\" rel=\"noopener\">\u30b5\u30d6\u30cd\u30c3\u30c8\u8a08\u7b97\u6a5f<\/a>\u306bCIDR\u3092\u5165\u529b\u3059\u308c\u3070\u3001\u30cd\u30c3\u30c8\u30ef\u30fc\u30af\u30a2\u30c9\u30ec\u30b9\u30fb\u30d6\u30ed\u30fc\u30c9\u30ad\u30e3\u30b9\u30c8\u30fb\u5229\u7528\u53ef\u80fd\u30db\u30b9\u30c8\u6570\u3092\u307e\u3068\u3081\u3066\u78ba\u8a8d\u3067\u304d\u307e\u3059\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">IPv6\u306e\u30b5\u30d6\u30cd\u30c3\u30c8\u306f\u8003\u3048\u65b9\u304c\u9055\u3046<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">IPv6\u3067\u306f<strong>\/64\u304c1\u3064\u306e\u30cd\u30c3\u30c8\u30ef\u30fc\u30af\u306e\u57fa\u672c\u5358\u4f4d<\/strong>\u3067\u3059\u3002IPv4\u306e\u3088\u3046\u306b\u300c\u53f0\u6570\u306b\u5408\u308f\u305b\u3066\u30db\u30b9\u30c8\u90e8\u3092\u5207\u308a\u8a70\u3081\u308b\u300d\u767a\u60f3\u306f\u307b\u3068\u3093\u3069\u4f7f\u3044\u307e\u305b\u3093\u3002\u30a2\u30c9\u30ec\u30b9\u304c\u6f64\u6ca2\u306b\u3042\u308b\u305f\u3081\u3001\u672b\u7aef\u306eLAN\u306b\u3082\u4f59\u88d5\u3092\u3082\u3063\u3066\/64\u3092\u5272\u308a\u5f53\u3066\u308b\u306e\u304c\u6a19\u6e96\u7684\u3067\u3059\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u307e\u305f<strong>IPv6\u306b\u30d6\u30ed\u30fc\u30c9\u30ad\u30e3\u30b9\u30c8\u306e\u6982\u5ff5\u306f\u3042\u308a\u307e\u305b\u3093<\/strong>\u3002\u305d\u306e\u5f79\u5272\u306f\u30de\u30eb\u30c1\u30ad\u30e3\u30b9\u30c8\u304c\u62c5\u3044\u307e\u3059\u3002IPv4\u306e\u611f\u899a\u3067\u300c\u672b\u5c3e\u306e\u30a2\u30c9\u30ec\u30b9\u306f\u4f7f\u3048\u306a\u3044\u300d\u3068\u8003\u3048\u308b\u5fc5\u8981\u306f\u3042\u308a\u307e\u305b\u3093\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">\u81ea\u5206\u306e\u30b5\u30a4\u30c8\u306fIPv6\u306b\u5bfe\u5fdc\u3057\u3066\u3044\u308b\u304b<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">IPv6\u5bfe\u5fdc\u306e\u7b2c\u4e00\u6b69\u306f\u3001DNS\u306b<strong>AAAA\u30ec\u30b3\u30fc\u30c9\u304c\u8a2d\u5b9a\u3055\u308c\u3066\u3044\u308b\u304b<\/strong>\u3067\u3059\u3002<a href=\"https:\/\/www.theipv6portal.org\/ipv6check\" target=\"_blank\" rel=\"noopener\">IPv6\u5bfe\u5fdc\u30c1\u30a7\u30c3\u30ab\u30fc<\/a>\u3067\u30c9\u30e1\u30a4\u30f3\u3092\u5165\u529b\u3059\u308c\u3070\u3001AAAA\u30ec\u30b3\u30fc\u30c9\u306e\u6709\u7121\u3092\u78ba\u8a8d\u3067\u304d\u307e\u3059\u3002\u30a2\u30c9\u30ec\u30b9\u306e\u7701\u7565\u5f62\u30fb\u5b8c\u5168\u5f62\u306e\u76f8\u4e92\u5909\u63db\u306f<a href=\"https:\/\/www.theipv6portal.org\/ipv6convert\" target=\"_blank\" rel=\"noopener\">IPv6\u30a2\u30c9\u30ec\u30b9\u5909\u63db\u30c4\u30fc\u30eb<\/a>\u304c\u4fbf\u5229\u3067\u3059\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">\u307e\u3068\u3081<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>IPv4\u306f32\u30d3\u30c3\u30c8\u7d0443\u5104\u500b\u3067\u3001\u65b0\u898f\u5272\u308a\u5f53\u3066\u306f\u4e8b\u5b9f\u4e0a\u7d42\u4e86\u3057\u3066\u3044\u308b<\/li>\n<li>IPv6\u306f\u300c::\u300d\u306b\u3088\u308b\u7701\u7565\u304c1\u56de\u3060\u3051\u53ef\u80fd\u3002\u6bd4\u8f03\u6642\u306f\u6b63\u898f\u5316\u3057\u3066\u304b\u3089\u6271\u3046<\/li>\n<li>CIDR\u306e\u300c\/n\u300d\u306f\u30cd\u30c3\u30c8\u30ef\u30fc\u30af\u90e8\u306e\u30d3\u30c3\u30c8\u6570\u3002\u6b8b\u308a\u304c\u30db\u30b9\u30c8\u90e8\u306b\u306a\u308b<\/li>\n<li>IPv6\u306f\/64\u304c\u57fa\u672c\u5358\u4f4d\u3067\u3001\u30d6\u30ed\u30fc\u30c9\u30ad\u30e3\u30b9\u30c8\u306f\u5b58\u5728\u3057\u306a\u3044<\/li>\n<\/ul>\n\n","protected":false},"excerpt":{"rendered":"<p>IPv6\u306e\u7701\u7565\u8868\u8a18\u30eb\u30fc\u30eb\u3068\u3001CIDR\u8868\u8a18\u306e\u8aad\u307f\u65b9\u3092\u56f3\u89e3\u3002IPv4\u3068IPv6\u3067\u30b5\u30d6\u30cd\u30c3\u30c8\u306e\u8003\u3048\u65b9\u304c\u3069\u3046\u9055\u3046\u306e\u304b\u3092\u6574\u7406\u3057\u307e\u3059\u3002<\/p>\n","protected":false},"author":0,"featured_media":6,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"swell_btn_cv_data":"","footnotes":""},"categories":[4],"tags":[],"class_list":["post-14","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-ip-ipv6"],"_links":{"self":[{"href":"https:\/\/www.theipv6portal.org\/column\/wp-json\/wp\/v2\/posts\/14","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.theipv6portal.org\/column\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.theipv6portal.org\/column\/wp-json\/wp\/v2\/types\/post"}],"replies":[{"embeddable":true,"href":"https:\/\/www.theipv6portal.org\/column\/wp-json\/wp\/v2\/comments?post=14"}],"version-history":[{"count":1,"href":"https:\/\/www.theipv6portal.org\/column\/wp-json\/wp\/v2\/posts\/14\/revisions"}],"predecessor-version":[{"id":21,"href":"https:\/\/www.theipv6portal.org\/column\/wp-json\/wp\/v2\/posts\/14\/revisions\/21"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.theipv6portal.org\/column\/wp-json\/wp\/v2\/media\/6"}],"wp:attachment":[{"href":"https:\/\/www.theipv6portal.org\/column\/wp-json\/wp\/v2\/media?parent=14"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.theipv6portal.org\/column\/wp-json\/wp\/v2\/categories?post=14"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.theipv6portal.org\/column\/wp-json\/wp\/v2\/tags?post=14"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}