{"id":338,"date":"2025-06-14T15:54:00","date_gmt":"2025-06-14T06:54:00","guid":{"rendered":"https:\/\/ccna-curriculum.tech-village.co.jp\/?p=338"},"modified":"2025-10-22T12:26:21","modified_gmt":"2025-10-22T03:26:21","slug":"gre","status":"publish","type":"post","link":"https:\/\/ccna-curriculum.tech-village.co.jp\/?p=338","title":{"rendered":"GRE"},"content":{"rendered":"\n<h2 class=\"wp-block-heading\">GRE\u3068\u306f<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><span class=\"swl-marker mark_yellow\">GRE\uff08Generic Routing Encapsulation\uff09<\/span><\/strong>\u306f\u3001\u30cd\u30c3\u30c8\u30ef\u30fc\u30af\u4e0a\u3067<strong><span class=\"swl-marker mark_yellow\">\u7570\u306a\u308b\u30d7\u30ed\u30c8\u30b3\u30eb\u306e\u30d1\u30b1\u30c3\u30c8\u3092IP\u3067\u30ab\u30d7\u30bb\u30eb\u5316\u3057\u3066\u9001\u308b\u305f\u3081\u306e\u30c8\u30f3\u30cd\u30eb\u6280\u8853<\/span><\/strong>\u3067\u3059\u3002\u30c8\u30f3\u30cd\u30eb\u30d7\u30ed\u30c8\u30b3\u30eb\u306b\u306f\u3001L2\u30ec\u30d9\u30eb\u306eL2F\u3084PPTP\u3001L2TP\u306a\u3069\u3068\u3001L3\u30ec\u30d9\u30eb\u306eGRE\u3084IPsec\u304c\u3042\u308a\u307e\u3059\u3002\u305d\u306e\u4e2d\u3067GRE\u306f\u3001\u7279\u306b\u300c\u4efb\u610f\u306e\u30d7\u30ed\u30c8\u30b3\u30eb\u3092IP\u30c8\u30f3\u30cd\u30eb\u306b\u8f09\u305b\u3089\u308c\u308b\u67d4\u8edf\u6027\u300d\u304c\u7279\u5fb4\u3067\u3059\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">GRE\u30c8\u30f3\u30cd\u30eb\u3067\u306f\u3001\u30d1\u30b1\u30c3\u30c8\u306f\u9001\u4fe1\u5074\u30eb\u30fc\u30bf\u3067GRE\u30d8\u30c3\u30c0\u3068\u65b0\u3057\u3044IP\u30d8\u30c3\u30c0\u3092\u4ed8\u52a0\u3055\u308c\u3001\u53d7\u4fe1\u5074\u30eb\u30fc\u30bf\u3067\u305d\u308c\u304c\u89e3\u9664\u3055\u308c\u307e\u3059\u3002\u3053\u308c\u306b\u3088\u308a\u3001\u5b9f\u969b\u306b\u306f\u30a4\u30f3\u30bf\u30fc\u30cd\u30c3\u30c8\u3092\u7d4c\u7531\u3057\u3066\u3044\u3066\u3082\u3001\u4e21\u7aef\u306e\u30eb\u30fc\u30bf\u9593\u306f<strong><span class=\"swl-marker mark_yellow\">\u4eee\u60f3\u7684\u306b\u76f4\u7d50\u3057\u3066\u3044\u308b\u3088\u3046\u306b\u898b\u3048\u308b<\/span><\/strong>\u306e\u3067\u3059\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u305f\u3060\u3057\u3001GRE\u81ea\u4f53\u306b\u306f\u6697\u53f7\u5316\u6a5f\u80fd\u306f\u3042\u308a\u307e\u305b\u3093\u3002\u305d\u306e\u305f\u3081\u300c\u30eb\u30fc\u30c6\u30a3\u30f3\u30b0\u60c5\u5831\u3092\u96a0\u3059\u300d\u3053\u3068\u306f\u3067\u304d\u307e\u3059\u304c\u3001\u30c7\u30fc\u30bf\u305d\u306e\u3082\u306e\u306f\u6697\u53f7\u5316\u3055\u308c\u305a\u3001\u30d1\u30b1\u30c3\u30c8\u89e3\u6790\u30c4\u30fc\u30eb\u3092\u4f7f\u3048\u3070\u4e2d\u8eab\u3092\u898b\u3089\u308c\u3066\u3057\u307e\u3044\u307e\u3059\u3002\u3082\u3057\u30bb\u30ad\u30e5\u30ea\u30c6\u30a3\u3092\u5f37\u5316\u3057\u305f\u3044\u5834\u5408\u306f<strong><span class=\"swl-marker mark_yellow\">GRE over IPsec<\/span><\/strong>\uff08GRE\u30c8\u30f3\u30cd\u30eb\u3092IPsec\u3067\u6697\u53f7\u5316\uff09\u3092\u5229\u7528\u3057\u307e\u3059\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u3055\u3089\u306bGRE\u306f\u3001\u30de\u30eb\u30c1\u30ad\u30e3\u30b9\u30c8\u3092\u4f7f\u3046\u30eb\u30fc\u30c6\u30a3\u30f3\u30b0\u30d7\u30ed\u30c8\u30b3\u30eb\uff08OSPF\u3084EIGRP\u306a\u3069\uff09\u3082\u30c8\u30f3\u30cd\u30eb\u4e0a\u3067\u5229\u7528\u53ef\u80fd\u3067\u3059\u3002\u3053\u308c\u306f\u3001IPsec\u5358\u72ec\u3067\u306f\u3067\u304d\u306a\u3044\u91cd\u8981\u306a\u30dd\u30a4\u30f3\u30c8\u3067\u3059\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">\u30c8\u30f3\u30cd\u30ea\u30f3\u30b0\u306e3\u3064\u306e\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">\u30c8\u30f3\u30cd\u30eb\u6280\u8853\u306b\u306f\u3001\u6b21\u306e3\u3064\u306e\u8981\u7d20\u304c\u95a2\u308f\u308a\u307e\u3059\u3002GRE\u3082\u3053\u306e\u67a0\u7d44\u307f\u3067\u8aac\u660e\u3067\u304d\u307e\u3059\u3002<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table><thead><tr><th>\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8<\/th><th>\u5185\u5bb9<\/th><\/tr><\/thead><tbody><tr><td>Transport Protocol<\/td><td>\u30ab\u30d7\u30bb\u30eb\u5316\u3057\u305f\u30c7\u30fc\u30bf\u3092\u904b\u3076\u305f\u3081\u306e\u5916\u5074\u306e\u30d7\u30ed\u30c8\u30b3\u30eb\uff08IP\u304c\u4e00\u822c\u7684\uff09<\/td><\/tr><tr><td>Passenger Protocol<\/td><td>\u4e2d\u306b\u5165\u308c\u3066\u904b\u3070\u308c\u308b\u5143\u306e\u30d7\u30ed\u30c8\u30b3\u30eb\uff08IP\u3001IPX\u3001AppleTalk\u306a\u3069\uff09<\/td><\/tr><tr><td>Carrier Protocol<\/td><td>\u30ab\u30d7\u30bb\u30eb\u5316\u306b\u4f7f\u3046\u30d7\u30ed\u30c8\u30b3\u30eb\uff08GRE\u306a\u3069\uff09<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">GRE\u306e\u5834\u5408\u3001\u5178\u578b\u7684\u306b\u306f\u300cPassenger Protocol = IP\u300d\u300cCarrier Protocol = GRE\u300d\u300cTransport Protocol = IP\u300d\u3068\u3044\u3046\u7d44\u307f\u5408\u308f\u305b\u306b\u306a\u308a\u307e\u3059\u3002\u3064\u307e\u308a\u300cIP\u306e\u4e2d\u306bGRE\u3092\u5165\u308c\u3066\u3001\u305d\u306e\u4e2d\u306b\u3055\u3089\u306bIP\u3092\u5165\u308c\u308b\u300d\u69cb\u9020\u306b\u306a\u308b\u308f\u3051\u3067\u3059\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u3053\u306e\u305f\u3081GRE\u3067\u9001\u4fe1\u3055\u308c\u308b\u30d1\u30b1\u30c3\u30c8\u306b\u306f\u3001\u65b0\u3057\u3044IP\u30d8\u30c3\u30c0\u3068GRE\u30d8\u30c3\u30c0\u304c\u8ffd\u52a0\u3055\u308c\u307e\u3059\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">GRE\u30c8\u30f3\u30cd\u30ea\u30f3\u30b0\u306e\u30c8\u30e9\u30d5\u30a3\u30c3\u30af\u30d5\u30ed\u30fc<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u4f8b\u3068\u3057\u3066\u3001\u62e0\u70b9R2\u306eLAN\uff08192.168.2.0\/24\uff09\u304b\u3089\u672c\u793eR1\u306eLAN\uff08192.168.1.0\/24\uff09\u3078\u901a\u4fe1\u3059\u308b\u30b1\u30fc\u30b9\u3092\u8003\u3048\u307e\u3059\u3002<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>R2\u3067\u9001\u4fe1\u3055\u308c\u305f192.168.2.x \u2192 192.168.1.x\u5b9b\u306e\u30d1\u30b1\u30c3\u30c8\u306f\u3001\u30eb\u30fc\u30c6\u30a3\u30f3\u30b0\u30c6\u30fc\u30d6\u30eb\u306b\u3088\u308a\u300c\u30cd\u30af\u30b9\u30c8\u30db\u30c3\u30d7\u304cTunnel0\u300d\u3068\u5224\u65ad\u3055\u308c\u307e\u3059\u3002<\/li>\n\n\n\n<li>R2\u306f\u305d\u306e\u30d1\u30b1\u30c3\u30c8\u306b<strong>\u65b0\u3057\u3044IP\u30d8\u30c3\u30c0\uff08\u9001\u4fe1\u5143\uff1dR2\u306eWAN IP\u3001\u5b9b\u5148\uff1dR1\u306eWAN IP\uff09\u3068GRE\u30d8\u30c3\u30c0<\/strong>\u3092\u8ffd\u52a0\u3057\u3066\u30a4\u30f3\u30bf\u30fc\u30cd\u30c3\u30c8\u306b\u9001\u4fe1\u3057\u307e\u3059\u3002<\/li>\n\n\n\n<li>\u30d1\u30b1\u30c3\u30c8\u3092\u53d7\u3051\u53d6\u3063\u305fR1\u306fGRE\u30d8\u30c3\u30c0\u3068\u5916\u5074\u306eIP\u30d8\u30c3\u30c0\u3092\u5916\u3057\u3001\u4e2d\u306e\u30aa\u30ea\u30b8\u30ca\u30eb\u30d1\u30b1\u30c3\u30c8\uff08192.168.2.x \u2192 192.168.1.x\uff09\u3092LAN\u5074\u306b\u8ee2\u9001\u3057\u307e\u3059\u3002<\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\">GRE\u306f\u6697\u53f7\u5316\u3057\u306a\u3044\u305f\u3081\u4e2d\u8eab\u306f\u4fdd\u8b77\u3055\u308c\u307e\u305b\u3093\u304c\u3001\u30d7\u30e9\u30a4\u30d9\u30fc\u30c8IP\u30a2\u30c9\u30ec\u30b9\u3092\u96a0\u3057\u305f\u308a\u3001\u3042\u308b\u7d4c\u8def\u3092\u5916\u90e8\u306b\u77e5\u3089\u305b\u305a\u306b\u62e0\u70b9\u9593\u901a\u4fe1\u3092\u884c\u3063\u305f\u308a\u3059\u308b\u5834\u5408\u306b\u306f\u6709\u52b9\u3067\u3059\u3002\u307e\u305f\u3001\u30c8\u30f3\u30cd\u30eb\u306f\u300c\u30dd\u30a4\u30f3\u30c8\u30c4\u30fc\u30dd\u30a4\u30f3\u30c8\u300d\u306e\u95a2\u4fc2\u3092\u4f5c\u308b\u306e\u3067\u3001\u4e2d\u7d99\u30eb\u30fc\u30bf\u306bLAN\u306e\u30eb\u30fc\u30c8\u3092\u77e5\u3089\u305b\u308b\u5fc5\u8981\u304c\u3042\u308a\u307e\u305b\u3093\u3002\u305d\u306e\u7d50\u679c\u3001\u30eb\u30fc\u30c6\u30a3\u30f3\u30b0\u60c5\u5831\u306b\u5bfe\u3059\u308b\u30bb\u30ad\u30e5\u30ea\u30c6\u30a3\u306f\u4fdd\u305f\u308c\u307e\u3059\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u3057\u304b\u3057\u3001<strong><span class=\"swl-marker mark_yellow\">\u30eb\u30fc\u30c6\u30a3\u30f3\u30b0\u60c5\u5831\u3060\u3051\u3067\u306a\u304f\u5b9f\u969b\u306e\u901a\u4fe1\u5185\u5bb9\u3082\u5b88\u308a\u305f\u3044\u5834\u5408\u306f\u3001GRE\u3068IPsec\u3092\u7d44\u307f\u5408\u308f\u305b\u308b\u3053\u3068\u304c\u5fc5\u9808<\/span><\/strong>\u3067\u3059\u3002<\/p>\n\n\n\n<p class=\"is-style-icon_pen wp-block-paragraph\">\u30fbGRE\u306f\u6697\u53f7\u5316\u3057\u306a\u3044\u305f\u3081\u30bb\u30ad\u30e5\u30ea\u30c6\u30a3\u306f\u9650\u5b9a\u7684<br>\u30fb\u30de\u30eb\u30c1\u30ad\u30e3\u30b9\u30c8\u3092\u30b5\u30dd\u30fc\u30c8\u3059\u308b\u306e\u3067\u3001\u30c0\u30a4\u30ca\u30df\u30c3\u30af\u30eb\u30fc\u30c6\u30a3\u30f3\u30b0\u304c\u53ef\u80fd<br>\u30fb\u300cPassenger Protocol\u300d\u300cCarrier Protocol\u300d\u300cTransport Protocol\u300d\u306e\u533a\u5225\u3092\u899a\u3048\u3066\u304a\u304f\u3053\u3068<br>\u30fbGRE over IPsec\u304c\u5b9f\u969b\u306eVPN\u3067\u3088\u304f\u4f7f\u308f\u308c\u308b\u69cb\u6210<br><br>\u3053\u3053\u3092\u62bc\u3055\u3048\u3066\u304a\u3051\u3070\u3001CCNA\u8a66\u9a13\u3067\u3082\u51fa\u984c\u306b\u5bfe\u5fdc\u3067\u304d\u307e\u3059\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">GRE\u306e\u30b3\u30f3\u30d5\u30a3\u30b0\u8a2d\u5b9a<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">GRE\u30c8\u30f3\u30cd\u30eb\u3092\u5229\u7528\u3059\u308b\u306b\u306f\u3001Cisco\u30eb\u30fc\u30bf\u3067\u30c8\u30f3\u30cd\u30eb\u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\u3092\u4f5c\u6210\u3057\u3001\u9001\u4fe1\u5143\u3068\u5b9b\u5148\u3092\u6307\u5b9a\u3059\u308b\u5fc5\u8981\u304c\u3042\u308a\u307e\u3059\u3002\u3053\u308c\u306b\u3088\u308a\u3001\u4eee\u60f3\u7684\u306b\u30eb\u30fc\u30bf\u540c\u58eb\u304c\u76f4\u7d50\u3057\u3066\u3044\u308b\u3088\u3046\u306b\u898b\u3048\u308b\u74b0\u5883\u3092\u4f5c\u308a\u51fa\u305b\u307e\u3059\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">\u30c8\u30f3\u30cd\u30eb\u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\u306e\u57fa\u672c\u8a2d\u5b9a<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>(config)# interface tunnel number\n(config-if)# ip address address mask\n(config-if)# tunnel source address | interface\n(config-if)# tunnel destination address\n(config-if)# tunnel mode gre ip<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li>number: \u4efb\u610f\u306e\u756a\u53f7\uff08\u4e21\u7aef\u3067\u5408\u308f\u305b\u308b\u5fc5\u8981\u306f\u306a\u3044\uff09<\/li>\n\n\n\n<li>ip address: \u30c8\u30f3\u30cd\u30eb\u7528\u306eIP\u30a2\u30c9\u30ec\u30b9<\/li>\n\n\n\n<li>tunnel source: \u30c8\u30f3\u30cd\u30eb\u9001\u4fe1\u5143\u3068\u306a\u308bIP\u30a2\u30c9\u30ec\u30b9\u307e\u305f\u306f\u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9<\/li>\n\n\n\n<li>tunnel destination: \u30c8\u30f3\u30cd\u30eb\u5b9b\u5148\u306eIP\u30a2\u30c9\u30ec\u30b9<\/li>\n\n\n\n<li>tunnel mode gre ip: GRE\u30e2\u30fc\u30c9\u3092\u6307\u5b9a\uff08\u30c7\u30d5\u30a9\u30eb\u30c8\u3067GRE\u306a\u306e\u3067\u7701\u7565\u53ef\u80fd\uff09<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u9001\u4fe1\u5143\u3068\u5b9b\u5148\u306e\u9593\u3067IP\u5230\u9054\u6027\u304c\u3042\u308b\u3053\u3068\u304c\u524d\u63d0\u6761\u4ef6\u3067\u3059\u3002PING\u3067\u78ba\u8a8d\u3057\u3066\u304b\u3089\u8a2d\u5b9a\u3059\u308b\u306e\u304c\u78ba\u5b9f\u3067\u3059\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">GRE\u306e\u8a2d\u5b9a\u4f8b\uff08\u30b9\u30bf\u30c6\u30a3\u30c3\u30af\u30eb\u30fc\u30c6\u30a3\u30f3\u30b0\uff09<\/h3>\n\n\n\n<h4 class=\"wp-block-heading\">R1\u306e\u8a2d\u5b9a<\/h4>\n\n\n\n<pre class=\"wp-block-code\"><code>interface GigabitEthernet 0\/0\n ip address 1.1.1.1 255.255.255.252\ninterface GigabitEthernet 0\/1\n ip address 192.168.1.254 255.255.255.0\ninterface tunnel 0\n ip address 10.1.1.1 255.255.255.0\n tunnel source 1.1.1.1\n tunnel destination 2.2.2.2\nip route 192.168.2.0 255.255.255.0 tunnel 0<\/code><\/pre>\n\n\n\n<h4 class=\"wp-block-heading\">R2\u306e\u8a2d\u5b9a<\/h4>\n\n\n\n<pre class=\"wp-block-code\"><code>interface GigabitEthernet 0\/0\n ip address 2.2.2.2 255.255.255.252\ninterface GigabitEthernet 0\/1\n ip address 192.168.2.254 255.255.255.0\ninterface tunnel 0\n ip address 10.1.1.2 255.255.255.0\n tunnel source 2.2.2.2\n tunnel destination 1.1.1.1\nip route 192.168.1.0 255.255.255.0 tunnel 0<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u3053\u306e\u8a2d\u5b9a\u3067R1\u306eLAN\uff08192.168.1.0\/24\uff09\u3068R2\u306eLAN\uff08192.168.2.0\/24\uff09\u304cGRE\u30c8\u30f3\u30cd\u30eb\u3067\u63a5\u7d9a\u3055\u308c\u307e\u3059\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">GRE\u306e\u8a2d\u5b9a\u4f8b\uff08\u30c0\u30a4\u30ca\u30df\u30c3\u30af\u30eb\u30fc\u30c6\u30a3\u30f3\u30b0\uff09<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u30b9\u30bf\u30c6\u30a3\u30c3\u30af\u30eb\u30fc\u30c8\u3067\u306f\u306a\u304fOSPF\u3092\u4f7f\u7528\u3059\u308b\u5834\u5408\u306e\u4f8b\u3067\u3059\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">R1\u306e\u8a2d\u5b9a<\/h4>\n\n\n\n<pre class=\"wp-block-code\"><code>interface GigabitEthernet 0\/0\n ip address 1.1.1.1 255.255.255.252\ninterface GigabitEthernet 0\/1\n ip address 192.168.1.254 255.255.255.0\ninterface tunnel 0\n ip address 10.1.1.1 255.255.255.0\n tunnel source 1.1.1.1\n tunnel destination 2.2.2.2\nrouter ospf 1\n network 192.168.1.254 0.0.0.0 area 0\n network 10.1.1.1 0.0.0.0 area 0<\/code><\/pre>\n\n\n\n<h4 class=\"wp-block-heading\">R2\u306e\u8a2d\u5b9a<\/h4>\n\n\n\n<pre class=\"wp-block-code\"><code>interface GigabitEthernet 0\/0\n ip address 2.2.2.2 255.255.255.252\ninterface GigabitEthernet 0\/1\n ip address 192.168.2.254 255.255.255.0\ninterface tunnel 0\n ip address 10.1.1.2 255.255.255.0\n tunnel source 2.2.2.2\n tunnel destination 1.1.1.1\nrouter ospf 1\n network 192.168.2.254 0.0.0.0 area 0\n network 10.1.1.2 0.0.0.0 area 0<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u3053\u308c\u306b\u3088\u308a\u3001OSPF\u3067LAN\u3068\u30c8\u30f3\u30cd\u30eb\u30cd\u30c3\u30c8\u30ef\u30fc\u30af\u306e\u30eb\u30fc\u30c8\u304c\u4ea4\u63db\u3055\u308c\u307e\u3059\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">\u30c8\u30f3\u30cd\u30eb\u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\u306e\u30c7\u30d5\u30a9\u30eb\u30c8\u30e2\u30fc\u30c9<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Tunnel\u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\u306e\u30c7\u30d5\u30a9\u30eb\u30c8\u306fGRE\u3067\u3059\u3002\u7279\u5225\u306b\u6307\u5b9a\u3057\u306a\u304f\u3066\u3082GRE\u30c8\u30f3\u30cd\u30eb\u304c\u4f7f\u3048\u307e\u3059\u3002\u4ed6\u306e\u65b9\u5f0f\uff08IP over IP\u3084IPv6 over IPv4\u306a\u3069\uff09\u3092\u5229\u7528\u3059\u308b\u5834\u5408\u306f <code>tunnel mode<\/code> \u3067\u660e\u793a\u7684\u306b\u6307\u5b9a\u3057\u307e\u3059\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">GRE\u30c8\u30f3\u30cd\u30eb\u306eKeepalive<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">\u30c8\u30f3\u30cd\u30eb\u306eUp\/Down\u5224\u5b9a\u306f\u5b9b\u5148IP\u3078\u306e\u30eb\u30fc\u30c8\u6709\u7121\u306b\u4f9d\u5b58\u3059\u308b\u305f\u3081\u3001\u5b9f\u969b\u306b\u76f8\u624b\u30eb\u30fc\u30bf\u304c\u843d\u3061\u3066\u3044\u3066\u3082Up\u306e\u307e\u307e\u6b8b\u308b\u3053\u3068\u304c\u3042\u308a\u307e\u3059\u3002\u3053\u306e\u554f\u984c\u3092\u89e3\u6c7a\u3059\u308b\u305f\u3081\u306bKeepalive\u6a5f\u80fd\u3092\u5229\u7528\u3057\u307e\u3059\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>interface tunnel 0\n keepalive 5 3<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u3053\u306e\u5834\u5408\u30015\u79d2\u3054\u3068\u306bKeepalive\u3092\u9001\u308a\u30013\u56de\u5fdc\u7b54\u304c\u306a\u3051\u308c\u3070\u30c8\u30f3\u30cd\u30eb\u3092Down\u3068\u5224\u5b9a\u3057\u307e\u3059\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">GRE\u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\u306eMTU\u8abf\u6574<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">GRE\u30d8\u30c3\u30c0\u3068\u65b0\u3057\u3044IP\u30d8\u30c3\u30c0\u304c\u8ffd\u52a0\u3055\u308c\u308b\u305f\u3081\u3001\u30c8\u30f3\u30cd\u30eb\u306eMTU\u306f\u901a\u5e38\u306e\u7269\u7406I\/F\u3088\u308a24\u30d0\u30a4\u30c8\u5c0f\u3055\u304f\u306a\u308a1476\u30d0\u30a4\u30c8\u3067\u3059\u3002\u30d5\u30e9\u30b0\u30e1\u30f3\u30c8\u3092\u9632\u3050\u305f\u3081\u306bMSS\u8abf\u6574\u3092\u884c\u3044\u307e\u3059\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>interface GigabitEthernet0\/1\n ip tcp adjust-mss 1436<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u3053\u306e\u8a2d\u5b9a\u306b\u3088\u308a\u3001TCP\u30bb\u30c3\u30b7\u30e7\u30f3\u3067\u306e\u6700\u5927\u30bb\u30b0\u30e1\u30f3\u30c8\u30b5\u30a4\u30ba\u304c1436\u30d0\u30a4\u30c8\u306b\u5236\u9650\u3055\u308c\u3001\u4e0d\u8981\u306a\u30d5\u30e9\u30b0\u30e1\u30f3\u30c8\u304c\u9632\u6b62\u3055\u308c\u307e\u3059\u3002<\/p>\n\n\n\n<p class=\"is-style-icon_pen wp-block-paragraph\">\u30fbGRE\u306f\u6697\u53f7\u5316\u6a5f\u80fd\u3092\u6301\u305f\u306a\u3044\u306e\u3067\u5fc5\u8981\u306b\u5fdc\u3058\u3066IPsec\u3068\u4f75\u7528\u3059\u308b<br>\u30fb\u30de\u30eb\u30c1\u30ad\u30e3\u30b9\u30c8\u3084\u30c0\u30a4\u30ca\u30df\u30c3\u30af\u30eb\u30fc\u30c6\u30a3\u30f3\u30b0\u3092\u901a\u305b\u308b\u70b9\u304c\u5927\u304d\u306a\u7279\u5fb4<br>\u30fbKeepalive\u3067\u30c8\u30f3\u30cd\u30eb\u306e\u5065\u5168\u6027\u3092\u76e3\u8996\u3067\u304d\u308b<br>\u30fbMTU\u3068MSS\u306e\u8abf\u6574\u304c\u30d5\u30e9\u30b0\u30e1\u30f3\u30c8\u9632\u6b62\u306b\u6709\u52b9<br><br>\u3053\u306e\u6d41\u308c\u3092\u7406\u89e3\u3057\u3066\u304a\u304f\u3068\u3001\u5b9f\u6a5f\u64cd\u4f5c\u3084CCNA\u8a66\u9a13\u3067\u306eGRE\u95a2\u9023\u554f\u984c\u306b\u30b9\u30e0\u30fc\u30ba\u306b\u5bfe\u5fdc\u3067\u304d\u307e\u3059\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">GRE over IPsec\u3068\u306f<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><span class=\"swl-marker mark_yellow\">GRE over IPsec<\/span><\/strong>\u306f\u3001GRE\u30c8\u30f3\u30cd\u30eb\u306e\u4e0a\u306bIPsec\u6697\u53f7\u5316\u3092\u9069\u7528\u3059\u308b\u4ed5\u7d44\u307f\u3067\u3059\u3002GRE\u306f\u30de\u30eb\u30c1\u30ad\u30e3\u30b9\u30c8\u3084\u8907\u6570\u306eL3\u30d7\u30ed\u30c8\u30b3\u30eb\u3092\u30ab\u30d7\u30bb\u30eb\u5316\u3067\u304d\u308b\u67d4\u8edf\u6027\u3092\u6301\u3061\u3001IPsec\u306f\u6697\u53f7\u5316\u3068\u5b8c\u5168\u6027\u4fdd\u8b77\u3092\u63d0\u4f9b\u3057\u307e\u3059\u3002\u4e21\u8005\u3092\u7d44\u307f\u5408\u308f\u305b\u308b\u3053\u3068\u3067\u3001\u30bb\u30ad\u30e5\u30a2\u3067\u304b\u3064\u30eb\u30fc\u30c6\u30a3\u30f3\u30b0\u306b\u5bfe\u5fdc\u3057\u305fVPN\u3092\u69cb\u7bc9\u3067\u304d\u307e\u3059\u3002\u7279\u306b\u62e0\u70b9\u9593VPN\u3067OSPF\u3084EIGRP\u306a\u3069\u306e\u30c0\u30a4\u30ca\u30df\u30c3\u30af\u30eb\u30fc\u30c6\u30a3\u30f3\u30b0\u3092\u5229\u7528\u3059\u308b\u5834\u5408\u306b\u6709\u52b9\u3067\u3059\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">IPsec\u3068GRE\u306e\u6bd4\u8f03<\/h2>\n\n\n\n<figure class=\"wp-block-table\"><table><thead><tr><th>VPN\u30d7\u30ed\u30c8\u30b3\u30eb<\/th><th>\u30c8\u30f3\u30cd\u30eb\u5bfe\u8c61<\/th><th>\u4f1d\u9001\u53ef\u80fd\u30d7\u30ed\u30c8\u30b3\u30eb<\/th><th>\u30de\u30eb\u30c1\u30ad\u30e3\u30b9\u30c8\u5bfe\u5fdc<\/th><th>\u6697\u53f7\u5316<\/th><th>\u4e3b\u306a\u7528\u9014<\/th><\/tr><\/thead><tbody><tr><td>IPsec<\/td><td>IP<\/td><td>IP\u306e\u307f<\/td><td>\u00d7<\/td><td>\u25cb<\/td><td>\u30bb\u30ad\u30e5\u30a2\u306a\u30e6\u30cb\u30ad\u30e3\u30b9\u30c8VPN<\/td><\/tr><tr><td>GRE<\/td><td>IP<\/td><td>IP, IPX, AppleTalk\u306a\u3069<\/td><td>\u25cb<\/td><td>\u00d7<\/td><td>\u30de\u30eb\u30c1\u30d7\u30ed\u30c8\u30b3\u30eb\u3084\u52d5\u7684\u30eb\u30fc\u30c6\u30a3\u30f3\u30b0<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">GRE over IPsec\u306e\u57fa\u672c\u69cb\u6210<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">GRE\u3067\u30d7\u30e9\u30a4\u30d9\u30fc\u30c8\u30cd\u30c3\u30c8\u30ef\u30fc\u30af\u540c\u58eb\u3092\u63a5\u7d9a\u3057\u3001\u305d\u306eGRE\u30d1\u30b1\u30c3\u30c8\u81ea\u4f53\u3092IPsec\u3067\u6697\u53f7\u5316\u3057\u307e\u3059\u3002\u3053\u308c\u306b\u3088\u308a\u3001GRE\u306e\u67d4\u8edf\u6027\u3068IPsec\u306e\u30bb\u30ad\u30e5\u30ea\u30c6\u30a3\u3092\u540c\u6642\u306b\u4eab\u53d7\u3067\u304d\u307e\u3059\u3002\u6697\u53f7\u5316\u306e\u5bfe\u8c61\u306fGRE\u30c8\u30f3\u30cd\u30eb\u306e\u9001\u4fe1\u5143IP\u3068\u5b9b\u5148IP\u3068\u306a\u308a\u307e\u3059\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">R1\u306e\u8a2d\u5b9a\u4f8b<\/h4>\n\n\n\n<pre class=\"wp-block-code\"><code>crypto isakmp policy 1\n encr 3des\n hash md5\n authentication pre-share\n group 2\ncrypto isakmp key cisco address 200.1.1.1\ncrypto isakmp keepalive 30 on-demand\n\ncrypto ipsec transform-set IPSEC esp-3des esp-md5-hmac\n mode transport\n\ncrypto map M-ipsec 1 ipsec-isakmp\n set peer 200.1.1.1\n set transform-set IPSEC\n match address A-ipsec\n\ninterface Loopback0\n ip address 100.1.1.1 255.255.255.255\n\ninterface GigabitEthernet0\/1\n ip address 10.1.1.254 255.255.255.0\n ip tcp adjust-mss 1332\n\ninterface Tunnel1\n ip address 192.168.1.1 255.255.255.0\n ip mtu 1372\n tunnel source Dialer1\n tunnel destination 200.1.1.1\n\ninterface Dialer1\n ip unnumbered Loopback0\n encapsulation ppp\n dialer pool 1\n ppp authentication chap callin\n crypto map M-ipsec\n\nrouter ospf 1\n network 10.1.1.254 0.0.0.0 area 0\n network 192.168.1.1 0.0.0.0 area 0\n\nip access-list extended A-ipsec\n permit gre host 100.1.1.1 host 200.1.1.1\n\nip access-list extended A-security\n permit esp host 200.1.1.1 host 100.1.1.1\n permit udp host 200.1.1.1 host 100.1.1.1 eq isakmp\n permit gre host 200.1.1.1 host 100.1.1.1<\/code><\/pre>\n\n\n\n<h4 class=\"wp-block-heading\">R2\u306e\u8a2d\u5b9a\u4f8b<\/h4>\n\n\n\n<pre class=\"wp-block-code\"><code>crypto isakmp policy 1\n encr 3des\n hash md5\n authentication pre-share\n group 2\ncrypto isakmp key cisco address 100.1.1.1\ncrypto isakmp keepalive 30 on-demand\n\ncrypto ipsec transform-set IPSEC esp-3des esp-md5-hmac\n mode transport\n\ncrypto map M-ipsec 1 ipsec-isakmp\n set peer 100.1.1.1\n set transform-set IPSEC\n match address A-ipsec\n\ninterface Loopback0\n ip address 200.1.1.1 255.255.255.255\n\ninterface GigabitEthernet0\/1\n ip address 10.1.2.254 255.255.255.0\n ip tcp adjust-mss 1332\n\ninterface Tunnel1\n ip address 192.168.1.2 255.255.255.0\n ip mtu 1372\n tunnel source Dialer1\n tunnel destination 100.1.1.1\n\ninterface Dialer1\n ip unnumbered Loopback0\n encapsulation ppp\n dialer pool 1\n ppp authentication chap callin\n crypto map M-ipsec\n\nrouter ospf 1\n network 10.1.2.254 0.0.0.0 area 0\n network 192.168.1.2 0.0.0.0 area 0\n\nip access-list extended A-ipsec\n permit gre host 200.1.1.1 host 100.1.1.1\n\nip access-list extended A-security\n permit esp host 100.1.1.1 host 200.1.1.1\n permit udp host 100.1.1.1 host 200.1.1.1 eq isakmp\n permit gre host 100.1.1.1 host 200.1.1.1<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\">GRE over IPsec\u306e\u6ce8\u610f\u70b9<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>IPsec\u306e\u30e2\u30fc\u30c9\u306f\u30c8\u30e9\u30f3\u30b9\u30dd\u30fc\u30c8\u306b\u3059\u308b\u3053\u3068\u3067\u4e8c\u91cd\u30c8\u30f3\u30cd\u30ea\u30f3\u30b0\u3092\u907f\u3051\u308b<\/li>\n\n\n\n<li>MSS\u5024\u306f1332byte\u7a0b\u5ea6\u306b\u8abf\u6574\u3057\u3001\u30d5\u30e9\u30b0\u30e1\u30f3\u30c8\u3092\u9632\u3050<\/li>\n\n\n\n<li>MTU\u30821372\u306b\u8abf\u6574\u3057\u3066\u6574\u5408\u6027\u3092\u53d6\u308b<\/li>\n\n\n\n<li>ACL\u3067GRE\u30d7\u30ed\u30c8\u30b3\u30eb\u756a\u53f747\u3092\u660e\u793a\u7684\u306b\u8a31\u53ef\u3059\u308b<\/li>\n\n\n\n<li>OSPF\u306a\u3069\u306e\u30eb\u30fc\u30c6\u30a3\u30f3\u30b0\u30d7\u30ed\u30c8\u30b3\u30eb\u306f\u30c8\u30f3\u30cd\u30eb\u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\u4e0a\u3067\u6709\u52b9\u5316\u3059\u308b<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u3053\u306e\u3088\u3046\u306bGRE over IPsec\u306f\u3001GRE\u306e\u67d4\u8edf\u6027\u3068IPsec\u306e\u30bb\u30ad\u30e5\u30ea\u30c6\u30a3\u3092\u517c\u306d\u5099\u3048\u305fVPN\u30bd\u30ea\u30e5\u30fc\u30b7\u30e7\u30f3\u3068\u3057\u3066\u5b9f\u52d9\u3067\u3082\u3088\u304f\u5229\u7528\u3055\u308c\u307e\u3059\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">GRE over IPsec\u306e1\u5bfeN\uff08\u30cf\u30d6\uff06\u30b9\u30dd\u30fc\u30af\uff09\u69cb\u6210\u306e\u5168\u4f53\u50cf<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">\u62e0\u70b9\u304c3\u3064\u4ee5\u4e0a\u306b\u306a\u308b\u3068\u3001\u62e0\u70b9\u3069\u3046\u3057\u3092\u30d5\u30eb\u30e1\u30c3\u30b7\u30e5\u3067\u7d50\u3076\u3088\u308a\u3082\u3001\u4e2d\u592e\u62e0\u70b9\uff08\u30cf\u30d6\uff09\u306b\u96c6\u7d04\u3057\u5404\u62e0\u70b9\uff08\u30b9\u30dd\u30fc\u30af\uff09\u304c\u30cf\u30d6\u3060\u3051\u3068\u30c8\u30f3\u30cd\u30eb\u3092\u5f35\u308b\u65b9\u304c\u904b\u7528\u304c\u697d\u3067\u3059\u3002GRE over IPsec\u306a\u3089\u3001GRE\u3067OSPF\u306a\u3069\u306e\u30c0\u30a4\u30ca\u30df\u30c3\u30af\u30eb\u30fc\u30c6\u30a3\u30f3\u30b0\u3084\u30de\u30eb\u30c1\u30ad\u30e3\u30b9\u30c8\u3092\u901a\u3057\u3064\u3064\u3001\u305d\u306eGRE\u81ea\u4f53\u3092IPsec\u3067\u6697\u53f7\u5316\u3067\u304d\u307e\u3059\u3002\u3053\u3053\u3067\u306fPPPoE\u56de\u7dda\u3092\u60f3\u5b9a\u3057\u3001R1\u3092\u30cf\u30d6\u3001R2\/R3\u3092\u30b9\u30dd\u30fc\u30af\u3068\u3057\u3066\u89e3\u8aac\u3057\u307e\u3059\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">\u8a2d\u8a08\u65b9\u91dd\u3068\u8a66\u9a13\u3067\u72d9\u308f\u308c\u308b\u8981\u70b9<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">IPsec\u306f\u6697\u53f7\u5316\u3068\u5b8c\u5168\u6027\u3092\u62c5\u5f53\u3001GRE\u306f\u30c8\u30f3\u30cd\u30ea\u30f3\u30b0\u3068\u30de\u30eb\u30c1\u30ad\u30e3\u30b9\u30c8\u4f1d\u9001\u3092\u62c5\u5f53\u3057\u307e\u3059\u3002\u4e8c\u91cd\u306b\u300c\u30c8\u30f3\u30cd\u30eb\u300d\u3092\u4f5c\u3089\u306a\u3044\u305f\u3081\u3001IPsec\u306f\u30c8\u30e9\u30f3\u30b9\u30dd\u30fc\u30c8\u30e2\u30fc\u30c9\u3001GRE\u304c\u5b9f\u969b\u306e\u30c8\u30f3\u30cd\u30eb\u5f79\u3068\u3044\u3046\u5206\u62c5\u306b\u3057\u307e\u3059\u3002\u6697\u53f7\u30b9\u30a4\u30fc\u30c8\u306f\u5b9f\u52d9\u3067\u3082\u8a66\u9a13\u3067\u3082AES\u7cfb\uff0bSHA\u7cfb\u304c\u63a8\u5968\u3067\u3059\u3002PPPoE\u3067\u306fMTU\u304c\u5c0f\u3055\u304f\u306a\u308b\u305f\u3081\u3001\u30c8\u30f3\u30cd\u30ebMTU\u3068MSS\u8abf\u6574\u3092\u884c\u3044\u30d5\u30e9\u30b0\u30e1\u30f3\u30c8\u3092\u907f\u3051\u307e\u3059\u3002ACL\u306f\u5f79\u5272\u3054\u3068\u306b\u5206\u3051\u3001IPsec\u5bfe\u8c61\uff08GRE\u306e\u9001\u53d7\u5143IP\uff09\u3001\u56de\u7dda\u5074\u8a31\u53ef\uff08ISAKMP\/ESP\/GRE\uff09\u3092\u6df7\u540c\u3057\u306a\u3044\u3088\u3046\u306b\u3057\u307e\u3059\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">\u30cf\u30d6\u30fb\u30b9\u30dd\u30fc\u30af\u3054\u3068\u306eIPsec\u30d1\u30e9\u30e1\u30fc\u30bf\u6574\u7406<\/h2>\n\n\n\n<figure class=\"wp-block-table\"><table><thead><tr><th>\u5f79\u5272<\/th><th>IKEv1 Phase1<\/th><th>IKEv1 Phase2<\/th><\/tr><\/thead><tbody><tr><td>\u30cf\u30d6R1 \u2192 \u30b9\u30dd\u30fc\u30afR2\/R3<\/td><td>\u6697\u53f7=AES\u3001\u30cf\u30c3\u30b7\u30e5=SHA-1\u3001\u8a8d\u8a3c=PSK\u3001DH=\u30b0\u30eb\u30fc\u30d72\u3001\u30e9\u30a4\u30d5\u30bf\u30a4\u30e0=86400\u79d2\u3001DPD=30<\/td><td>\u30d7\u30ed\u30c8\u30b3\u30eb=ESP\u3001\u6697\u53f7=AES\u3001\u8a8d\u8a3c=HMAC-SHA1\u3001\u30e2\u30fc\u30c9=transport\u3001\u30e9\u30a4\u30d5\u30bf\u30a4\u30e0=3600\u79d2\u3001PFS=\u306a\u3057<\/td><\/tr><tr><td>\u30b9\u30dd\u30fc\u30afR2\/R3 \u2192 \u30cf\u30d6R1<\/td><td>\u540c\u4e0a\uff08\u76f8\u624b\u304cR1\u4e00\u629e\uff09<\/td><td>\u540c\u4e0a<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"is-style-icon_pen wp-block-paragraph\">\u3053\u3053\u306f\u5fc5\u305a\u899a\u3048\u308b\uff1aGRE over IPsec\u3067\u306f\u300cIPsec\u306ftransport\u300d\u300c\u6697\u53f7\u5316\u5bfe\u8c61ACL\u306fGRE\u306e\u9001\u53d7\u5143IP\u300d\u304c\u5b9a\u756a\u3067\u3059\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">\u30cf\u30d6R1\u306e\u4ee3\u8868\u30b3\u30f3\u30d5\u30a3\u30b0<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>! IKE Phase1\uff08\u8907\u6570\u30d4\u30a2\u3092\u767b\u9332\uff09\ncrypto isakmp policy 1\n encr aes\n hash sha\n authentication pre-share\n group 2\ncrypto isakmp key cisco address 102.1.1.1\ncrypto isakmp key cisco address 103.1.1.1\ncrypto isakmp keepalive 30 on-demand\n\n! IKE Phase2\uff08AES+SHA\u3001transport\uff09\ncrypto ipsec transform-set IPSEC esp-aes esp-sha-hmac\n mode transport\n\n! 2\u672c\u306eIPsec\u30bb\u30c3\u30b7\u30e7\u30f3\u3092\u6697\u53f7\u30de\u30c3\u30d7\u3067\u675f\u306d\u308b\uff08Seq\u756a\u53f7\u3067\u512a\u5148\uff09\ncrypto map M-IPSEC 1 ipsec-isakmp\n set peer 102.1.1.1\n set transform-set IPSEC\n match address A-IPSEC-R2\ncrypto map M-IPSEC 2 ipsec-isakmp\n set peer 103.1.1.1\n set transform-set IPSEC\n match address A-IPSEC-R3\n\n! \u30eb\u30fc\u30bfI\/F\ninterface Loopback1\n ip address 101.1.1.1 255.255.255.255\n\ninterface GigabitEthernet0\/1\n ip address 10.1.1.254 255.255.255.0\n ip tcp adjust-mss 1332\n\n! GRE\u30c8\u30f3\u30cd\u30eb\uff08R2\u7528\uff09\ninterface Tunnel1\n ip address 192.168.1.1 255.255.255.0\n ip mtu 1372\n tunnel source Dialer1\n tunnel destination 102.1.1.1\n\n! GRE\u30c8\u30f3\u30cd\u30eb\uff08R3\u7528\uff09\ninterface Tunnel2\n ip address 192.168.2.1 255.255.255.0\n ip mtu 1372\n tunnel source Dialer1\n tunnel destination 103.1.1.1\n\n! PPPoE\u5074\ninterface Dialer1\n ip unnumbered Loopback1\n ip access-group A-SECURITY in\n ip mtu 1454\n encapsulation ppp\n dialer pool 1\n ppp authentication chap callin\n ppp chap hostname cisco@cisco.com\n ppp chap password cisco\n crypto map M-IPSEC\n\n! OSPF\u306fLAN\u3068\u5404\u30c8\u30f3\u30cd\u30eb\u3092\u6709\u52b9\u5316\nrouter ospf 1\n log-adjacency-changes\n network 10.1.1.254 0.0.0.0 area 0\n network 192.168.1.1 0.0.0.0 area 0\n network 192.168.2.1 0.0.0.0 area 0\n\nip route 0.0.0.0 0.0.0.0 Dialer1\n\n! IPsec\u5bfe\u8c61ACL\uff1aGRE\u306e\u9001\u53d7\u5143\uff08R1\u2194R2\u3001R1\u2194R3\uff09\nip access-list extended A-IPSEC-R2\n permit gre host 101.1.1.1 host 102.1.1.1\nip access-list extended A-IPSEC-R3\n permit gre host 101.1.1.1 host 103.1.1.1\n\n! \u56de\u7dda\u5074\u306e\u6700\u4f4e\u9650\u8a31\u53ef\uff08ISAKMP\/ESP\/GRE\uff09\nip access-list extended A-SECURITY\n permit udp host 102.1.1.1 host 101.1.1.1 eq isakmp\n permit esp host 102.1.1.1 host 101.1.1.1\n permit gre host 102.1.1.1 host 101.1.1.1\n permit udp host 103.1.1.1 host 101.1.1.1 eq isakmp\n permit esp host 103.1.1.1 host 101.1.1.1\n permit gre host 103.1.1.1 host 101.1.1.1<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\">\u30b9\u30dd\u30fc\u30afR2\u306e\u4ee3\u8868\u30b3\u30f3\u30d5\u30a3\u30b0<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>crypto isakmp policy 1\n encr aes\n hash sha\n authentication pre-share\n group 2\ncrypto isakmp key cisco address 101.1.1.1\ncrypto isakmp keepalive 30 on-demand\n\ncrypto ipsec transform-set IPSEC esp-aes esp-sha-hmac\n mode transport\n\ncrypto map M-IPSEC 1 ipsec-isakmp\n set peer 101.1.1.1\n set transform-set IPSEC\n match address A-IPSEC\n\ninterface Loopback1\n ip address 102.1.1.1 255.255.255.255\n\ninterface GigabitEthernet0\/1\n ip address 10.1.2.254 255.255.255.0\n ip tcp adjust-mss 1332\n\ninterface Tunnel1\n ip address 192.168.1.2 255.255.255.0\n ip mtu 1372\n tunnel source Dialer1\n tunnel destination 101.1.1.1\n\ninterface Dialer1\n ip unnumbered Loopback1\n ip access-group A-SECURITY in\n ip mtu 1454\n encapsulation ppp\n dialer pool 1\n ppp authentication chap callin\n ppp chap hostname cisco@cisco.com\n ppp chap password cisco\n crypto map M-IPSEC\n\nrouter ospf 1\n log-adjacency-changes\n network 10.1.2.254 0.0.0.0 area 0\n network 192.168.1.2 0.0.0.0 area 0\n\nip route 0.0.0.0 0.0.0.0 Dialer1\n\n! IPsec\u5bfe\u8c61\uff1aGRE\uff08R2\u2192R1\uff09\nip access-list extended A-IPSEC\n permit gre host 102.1.1.1 host 101.1.1.1\n\n! \u56de\u7dda\u5074\u306e\u8a31\u53ef\uff08ISAKMP\/ESP\/GRE\uff09R1\u2192R2\u65b9\u5411\nip access-list extended A-SECURITY\n permit udp host 101.1.1.1 host 102.1.1.1 eq isakmp\n permit esp host 101.1.1.1 host 102.1.1.1\n permit gre host 101.1.1.1 host 102.1.1.1<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\">\u30b9\u30dd\u30fc\u30afR3\u306e\u4ee3\u8868\u30b3\u30f3\u30d5\u30a3\u30b0<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>crypto isakmp policy 1\n encr aes\n hash sha\n authentication pre-share\n group 2\ncrypto isakmp key cisco address 101.1.1.1\ncrypto isakmp keepalive 30 on-demand\n\ncrypto ipsec transform-set IPSEC esp-aes esp-sha-hmac\n mode transport\n\ncrypto map M-IPSEC 1 ipsec-isakmp\n set peer 101.1.1.1\n set transform-set IPSEC\n match address A-IPSEC\n\ninterface Loopback1\n ip address 103.1.1.1 255.255.255.255\n\ninterface GigabitEthernet0\/1\n ip address 10.1.3.254 255.255.255.0\n ip tcp adjust-mss 1332\n\ninterface Tunnel2\n ip address 192.168.2.2 255.255.255.0\n ip mtu 1372\n tunnel source Dialer1\n tunnel destination 101.1.1.1\n\ninterface Dialer1\n ip unnumbered Loopback1\n ip access-group A-SECURITY in\n ip mtu 1454\n encapsulation ppp\n dialer pool 1\n ppp authentication chap callin\n ppp chap hostname cisco@cisco.com\n ppp chap password cisco\n crypto map M-IPSEC\n\nrouter ospf 1\n log-adjacency-changes\n network 10.1.3.254 0.0.0.0 area 0\n network 192.168.2.2 0.0.0.0 area 0\n\nip route 0.0.0.0 0.0.0.0 Dialer1\n\nip access-list extended A-IPSEC\n permit gre host 103.1.1.1 host 101.1.1.1\n\nip access-list extended A-SECURITY\n permit udp host 101.1.1.1 host 103.1.1.1 eq isakmp\n permit esp host 101.1.1.1 host 103.1.1.1\n permit gre host 101.1.1.1 host 103.1.1.1<\/code><\/pre>\n\n\n\n<h2 class=\"wp-block-heading\">MTU\u3068MSS\u306e\u76ee\u5b89<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">PPPoE\u306e\u30aa\u30fc\u30d0\u30fc\u30d8\u30c3\u30c9\u3068GRE\u30d8\u30c3\u30c0\uff0824\u30d0\u30a4\u30c8\uff09\u3092\u898b\u8fbc\u3093\u3067\u3001\u30c8\u30f3\u30cd\u30ebMTU\u306f1372\u3001LAN\u5074MSS\u306f1332\u3092\u76ee\u5b89\u3068\u3057\u307e\u3059\u3002\u5b9f\u6a5f\u3067\u306f<code>show interfaces<\/code>\u3067\u5b9f\u6e2c\u3057\u3001\u5fc5\u8981\u306b\u5fdc\u3058\u3066\u5fae\u8abf\u6574\u3057\u307e\u3059\u3002\u30d5\u30e9\u30b0\u30e1\u30f3\u30c8\u304c\u51fa\u308b\u3068OSPF\u3084\u30a2\u30d7\u30ea\u306e\u4e0d\u8abf\u306b\u3064\u306a\u304c\u308b\u306e\u3067\u3053\u3053\u306f\u5916\u3055\u306a\u3044\u3088\u3046\u306b\u3057\u307e\u3059\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">\u52d5\u4f5c\u78ba\u8a8d\u306e\u624b\u9806<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">\u307e\u305a<code>show ip interface brief<\/code>\u3067\u5404Tunnel\u304cup\/up\u3067\u3042\u308b\u3053\u3068\u3092\u78ba\u8a8d\u3057\u307e\u3059\u3002\u6b21\u306b<code>show ip ospf neighbor<\/code>\u3067\u30cf\u30d6\u3068\u5404\u30b9\u30dd\u30fc\u30af\u306e\u30cd\u30a4\u30d0\u30fc\u304c\u5f62\u6210\u3055\u308c\u3066\u3044\u308b\u304b\u78ba\u8a8d\u3057\u307e\u3059\u3002IPsec\u306f<code>show crypto isakmp sa<\/code>\u3067\u30d5\u30a7\u30fc\u30ba1\u3001<code>show crypto ipsec sa<\/code>\u3067\u30d5\u30a7\u30fc\u30ba2\u3092\u78ba\u8a8d\u3057\u3001<code>#pkts encrypt<\/code>\u3068<code>#pkts decrypt<\/code>\u304c\u5897\u3048\u3066\u3044\u308b\u304b\u3092\u898b\u307e\u3059\u3002\u6697\u53f7\u5316\u5074\u3060\u3051\u5897\u3048\u308b\u306a\u3089\u81ea\u5c40\u304b\u3089\u306e\u9001\u51fa\u306f\u3067\u304d\u3066\u3044\u308b\u5408\u56f3\u3001\u5fa9\u53f7\u5074\u304c\u5897\u3048\u308b\u306a\u3089\u76f8\u624b\u304b\u3089\u306e\u53d7\u4fe1\u3082\u3067\u304d\u3066\u3044\u307e\u3059\u3002<\/p>\n\n\n\n<p class=\"is-style-icon_pen wp-block-paragraph\">\u6697\u53f7\u5316\u5bfe\u8c61ACL\u3092\u8aa4\u3063\u3066\u300cLAN\u30b5\u30d6\u30cd\u30c3\u30c8\u540c\u58eb\u300d\u3067\u66f8\u3044\u3066\u3057\u307e\u3046\u3068\u3001GRE\u30d8\u30c3\u30c0\u304c\u6697\u53f7\u5316\u5bfe\u8c61\u304b\u3089\u5916\u308c\u3066\u30c8\u30f3\u30cd\u30eb\u304c\u901a\u308a\u307e\u305b\u3093\u3002\u5fc5\u305aGRE\u306e\u9001\u53d7\u5143\uff08\u30cf\u30d6\/\u30b9\u30dd\u30fc\u30af\u306eLoopback\u3067\u6301\u3064\u30b0\u30ed\u30fc\u30d0\u30ebIP\uff09\u3092\u8a31\u53ef\u3057\u307e\u3059\u3002\u56de\u7dda\u5074ACL\u3067\u306fISAKMP(UDP\/500)\u30fbESP(50)\u30fb\u5fc5\u8981\u306a\u3089NAT-T(UDP\/4500)\u30fbGRE(47)\u306e\u901a\u904e\u3092\u5fd8\u308c\u306a\u3044\u3088\u3046\u306b\u3057\u307e\u3059\u3002PPPoE\u306eMSS\/MTU\u672a\u8abf\u6574\u3082\u5b9a\u756a\u306e\u843d\u3068\u3057\u7a74\u3067\u3059\u3002<\/p>\n\n\n\n<p class=\"is-style-icon_pen wp-block-paragraph\">GRE over IPsec\u3067\u306f\u3001IPsec\u3092\u30c8\u30e9\u30f3\u30b9\u30dd\u30fc\u30c8\u3001GRE\u3067\u30eb\u30fc\u30c6\u30a3\u30f3\u30b0\u3092\u901a\u3059\u3001\u6697\u53f7\u5316\u5bfe\u8c61\u306fGRE\u306e\u9001\u53d7\u5143IP\u3001\u3068\u3044\u30463\u70b9\u30bb\u30c3\u30c8\u304c\u5b9a\u756a\u3067\u3059\u3002\u30cf\u30d6\uff06\u30b9\u30dd\u30fc\u30af\u3067\u306f\u30cf\u30d6\u5074\u304c\u8907\u6570\u306e\u6697\u53f7\u30de\u30c3\u30d7\u30a8\u30f3\u30c8\u30ea\u3092\u6301\u3061\u3001\u30b9\u30dd\u30fc\u30af\u306f\u30cf\u30d6\u4e00\u629e\u3068\u3044\u3046\u5bfe\u79f0\u6027\u3082\u62bc\u3055\u3048\u3066\u304a\u304f\u3068\u3001\u51fa\u984c\u6587\u304b\u3089\u7d20\u65e9\u304f\u69cb\u6210\u3092\u30a4\u30e1\u30fc\u30b8\u3067\u304d\u307e\u3059\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">\u25c6\u307e\u3068\u3081\u30b9\u30e9\u30a4\u30c9<\/h2>\n\n\n\n<div data-wp-interactive=\"core\/file\" class=\"wp-block-file\"><object data-wp-bind--hidden=\"!state.hasPdfPreview\" hidden class=\"wp-block-file__embed\" data=\"https:\/\/ccna-curriculum.tech-village.co.jp\/wp-content\/uploads\/2025\/06\/GRE.pdf\" type=\"application\/pdf\" style=\"width:100%;height:600px\" aria-label=\"GRE\u306e\u57cb\u3081\u8fbc\u307f\u3002\"><\/object><a id=\"wp-block-file--media-cf51fe7f-b3ba-4985-a3b4-aa025fb9573e\" href=\"https:\/\/ccna-curriculum.tech-village.co.jp\/wp-content\/uploads\/2025\/06\/GRE.pdf\">GRE<\/a><\/div>\n","protected":false},"excerpt":{"rendered":"<p>GRE\u3068\u306f GRE\uff08Generic Routing Encapsulation\uff09\u306f\u3001\u30cd\u30c3\u30c8\u30ef\u30fc\u30af\u4e0a\u3067\u7570\u306a\u308b\u30d7\u30ed\u30c8\u30b3\u30eb\u306e\u30d1\u30b1\u30c3\u30c8\u3092IP\u3067\u30ab\u30d7\u30bb\u30eb\u5316\u3057\u3066\u9001\u308b\u305f\u3081\u306e\u30c8\u30f3\u30cd\u30eb\u6280\u8853\u3067\u3059\u3002\u30c8\u30f3\u30cd\u30eb\u30d7\u30ed\u30c8\u30b3\u30eb\u306b\u306f\u3001L2\u30ec\u30d9\u30eb\u306eL2F\u3084 [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"swell_btn_cv_data":"","footnotes":""},"categories":[15],"tags":[],"class_list":["post-338","post","type-post","status-publish","format-standard","hentry","category-security"],"_links":{"self":[{"href":"https:\/\/ccna-curriculum.tech-village.co.jp\/index.php?rest_route=\/wp\/v2\/posts\/338","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ccna-curriculum.tech-village.co.jp\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ccna-curriculum.tech-village.co.jp\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ccna-curriculum.tech-village.co.jp\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ccna-curriculum.tech-village.co.jp\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=338"}],"version-history":[{"count":4,"href":"https:\/\/ccna-curriculum.tech-village.co.jp\/index.php?rest_route=\/wp\/v2\/posts\/338\/revisions"}],"predecessor-version":[{"id":837,"href":"https:\/\/ccna-curriculum.tech-village.co.jp\/index.php?rest_route=\/wp\/v2\/posts\/338\/revisions\/837"}],"wp:attachment":[{"href":"https:\/\/ccna-curriculum.tech-village.co.jp\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=338"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ccna-curriculum.tech-village.co.jp\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=338"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ccna-curriculum.tech-village.co.jp\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=338"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}