{"id":492,"date":"2019-05-23T00:10:00","date_gmt":"2019-05-22T15:10:00","guid":{"rendered":""},"modified":"2020-10-02T22:28:00","modified_gmt":"2020-10-02T13:28:00","slug":"tunnel-over-tunnel-%e3%81%ae%e3%81%a8%e3%81%8d%e3%81%aemtu%e3%81%ab%e3%81%a4%e3%81%84%e3%81%a6","status":"publish","type":"post","link":"https:\/\/wp.zassoul.com\/?p=492","title":{"rendered":"Tunnel over Tunnel \u306e\u3068\u304d\u306eMTU\u306b\u3064\u3044\u3066"},"content":{"rendered":"

\u3042\u307e\u308a\u7121\u3044\u3068\u306f\u601d\u3044\u307e\u3059\u304c, Tunnel\u3092\u5f35\u3063\u305f\u5148\u3067\u66f4\u306bTunnel\u3092\u5f35\u308b\u3088\u3046\u306a\u69cb\u6210(Tunnel over Tunnel)\u306e\u3068\u304d, \u30a8\u30f3\u30c9\u9593\u3067\u306eDF\u30d3\u30c3\u30c8\u3092\u7acb\u3066\u305fping\u3067\u306fMTU\u5024\u3092\u6b63\u3057\u304f\u6e2c\u5b9a\u3067\u304d\u307e\u305b\u3093\u3002<\/p>\n

\u4f8b\u3048\u3070\u4ee5\u4e0b\u306e\u56f3\u306e\u69cb\u6210\u3092\u8003\u3048\u305f\u6642, PC1\u3068PC2\u3068\u306e\u901a\u4fe1\u306b\u304a\u3044\u3066GRE\u306e\u30ab\u30d7\u30bb\u30eb\u5316\u304c2\u56de\u304b\u304b\u308a\u307e\u3059\u3002<\/p>\n

\u305d\u306e\u6642\u3001PC1\uff5ePC2\u9593\u306e\u901a\u4fe1\u3067\u6700\u9069\u306aMTU\u5024\u306f<\/p>\n

1500 – 24 – 24 = 1452<\/p>\n

\u3068\u306a\u308a\u307e\u3059\u3002<\/p>\n\n\n\n\n
<\/a><\/td>\n<\/tr>\n
Gre over Gre \u69cb\u6210\u306e\u4e00\u4f8b<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

<\/p>\n

\u3057\u304b\u3057, Ping\u3067\u78ba\u8a8d\u3057\u3088\u3046\u3068\u3059\u308b\u3068, ICMP\u304c2\u56de\u30ab\u30d7\u30bb\u30eb\u5316\u3055\u308c\u3066\u3057\u307e\u3044, 2\u3064\u76ee\u306e\u30c8\u30f3\u30cd\u30eb\u3067\u306fDF\u30d3\u30c3\u30c8\u304c\u8a8d\u8b58\u3055\u308c\u305a\u30d5\u30e9\u30b0\u30e1\u30f3\u30c8\u3055\u308c\u3066\u3057\u307e\u3044\u307e\u3059\u3002<\/div>\n
<\/div>\n
\u305d\u306e\u305f\u3081, MTU\u304c\u5224\u5b9a\u3055\u308c\u308b\u306e\u306f1\u3064\u76ee\u306eGRE\u30c8\u30f3\u30cd\u30eb\u306e\u307f\u3068\u306a\u308a, \u6b63\u3057\u304fMTU\u3092\u8a08\u6e2c\u3055\u308c\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u305b\u3093\u3002<\/p>\n

\u4f8b\u3048\u3070PC1\u304b\u3089\u306eping\u306e\u7d50\u679c\u304c\u4ee5\u4e0b\u306e\u3088\u3046\u306b\u306a\u3063\u305f\u3068\u3057\u3066\u3082, 2\u672c\u76ee\u306eGRE\u30c8\u30f3\u30cd\u30eb\u306e\u4e2d\u3067\u306f\u30d5\u30e9\u30b0\u30e1\u30f3\u30c8\u5316\u3055\u308c\u3066\u3044\u307e\u3059\u3002<\/p><\/div>\n

<\/div>\n
$ \/bin\/ping 192.168.2.12 -s 1448 -M do
PING 192.168.2.12 (192.168.2.12) 1448(1476) bytes of data.
1456 bytes from 192.168.2.12: icmp_seq=1 ttl=62 time=1.70 ms
1456 bytes from 192.168.2.12: icmp_seq=2 ttl=62 time=1.81 ms
1456 bytes from 192.168.2.12: icmp_seq=3 ttl=62 time=6.20 ms
^C
--- 192.168.2.12 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2003ms
rtt min\/avg\/max\/mdev = 1.700\/3.239\/6.204\/2.097 ms

$ \/bin\/ping 192.168.2.12 -s 1449 -M do
PING 192.168.2.12 (192.168.2.12) 1449(1477) bytes of data.
ping: local error: Message too long, mtu=1476
ping: local error: Message too long, mtu=1476
ping: local error: Message too long, mtu=1476
^C
--- 192.168.2.12 ping statistics ---
3 packets transmitted, 0 received, +3 errors, 100% packet loss, time 2110ms
<\/pre>\n
<\/p>\n\n\n\n\n
<\/a><\/td>\n<\/tr>\n
ICMP\u304c\u30d5\u30e9\u30b0\u30e1\u30f3\u30c8\u5316\u3055\u308c\u3066\u3044\u308b\u69d8\u5b50<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
\u3053\u3046\u3044\u3063\u305f\u69cb\u6210\u3067\u306f, \u3057\u3063\u304b\u308aMTU\u5024\u3092\u8a08\u7b97\u3057, \u6700\u521d\u306e\u30eb\u30fc\u30bf\u306b\u304a\u3044\u3066\u9069\u5207\u306aMTU\u5024(\u4eca\u56de\u306e\u69cb\u6210\u3067\u306f1452\u30d0\u30a4\u30c8)\u3092\u8a2d\u5b9a\u3057\u3066\u304a\u304f\u5fc5\u8981\u304c\u3042\u308a\u307e\u3059\u3002<\/div>\n","protected":false},"excerpt":{"rendered":"
\u3042\u307e\u308a\u7121\u3044\u3068\u306f\u601d\u3044\u307e\u3059\u304c, Tunnel\u3092\u5f35\u3063\u305f\u5148\u3067\u66f4\u306bTunnel\u3092\u5f35\u308b\u3088\u3046\u306a\u69cb\u6210(Tunnel over Tunnel)\u306e\u3068\u304d, \u30a8\u30f3\u30c9\u9593\u3067\u306eDF\u30d3\u30c3\u30c8\u3092\u7acb\u3066\u305fping\u3067\u306fMTU\u5024\u3092\u6b63\u3057\u304f\u6e2c\u5b9a\u3067\u304d\u307e\u305b\u3093\u3002 \u4f8b\u3048\u3070\u4ee5\u4e0b\u2026 \u7d9a\u304d\u3092\u8aad\u3080 »<\/a><\/span><\/p>\n","protected":false},"author":1,"featured_media":235,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[38,37,15,8],"tags":[],"class_list":["post-492","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-gre","category-mtu","category-network","category-8"],"_links":{"self":[{"href":"https:\/\/wp.zassoul.com\/index.php?rest_route=\/wp\/v2\/posts\/492","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/wp.zassoul.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/wp.zassoul.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/wp.zassoul.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/wp.zassoul.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=492"}],"version-history":[{"count":1,"href":"https:\/\/wp.zassoul.com\/index.php?rest_route=\/wp\/v2\/posts\/492\/revisions"}],"predecessor-version":[{"id":629,"href":"https:\/\/wp.zassoul.com\/index.php?rest_route=\/wp\/v2\/posts\/492\/revisions\/629"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/wp.zassoul.com\/index.php?rest_route=\/wp\/v2\/media\/235"}],"wp:attachment":[{"href":"https:\/\/wp.zassoul.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=492"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wp.zassoul.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=492"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wp.zassoul.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=492"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}