NAT(Network Address Translation,\u7db2\u8def\u5730\u5740\u8f49\u63db)
\u5b9a\u7fa9\u5728RFC1631
\u4e00\u7a2e\u5728IP\u6578\u64da\u5305\u901a\u904e\u8def\u7531\u5668\u6216\u9632\u706b\u7246\u91cd\u5beb\u6e90IP\u5730\u5740\u6216\u76ee\u7684ip\u4f4d\u5740\u6280\u8853
\u539f\u7406:\u85c9\u7531\u542bIP\u4f4d\u5740\u7684\u8f49\u63db\u8868NAT mapping table\u4f86\u5c0d\u61c9\u90a3\u500b\u5c01\u5305\u662f\u5c6c\u65bc\u90a3\u500b\u96fb\u8166<\/p>\n\n\n\n
\u7528\u9014:
\u89e3\u6c7aip\u4f4d\u5740\u4e0d\u5920\u4f7f\u7528,\u6216\u4e0d\u60f3\u8b93\u5916\u90e8\u7528\u6236\u77e5\u9053\u5167\u90e8ip\u4f4d\u5740
\u666e\u904d\u7528\u5728\u591a\u53f0\u4e3b\u6a5f\u4f46\u53ea\u901a\u904e\u4e00\u500b\u516c\u6709IP\u5730\u5740\u5230\u7db2\u969b\u7db2\u8def
\u7528\u5728\u4e0d\u60f3\u90e8\u7f72Proxy\u4f3a\u670d\u5668\u7684\u74b0\u5883\u4e0b\u5b58\u53d6Internet\u8cc7\u6e90\u7684\u60c5\u6cc1
\u5be6\u4f5c:
\u4f4e\u901f\u7db2\u8def\u53ef\u7528\u8edf\u9ad4,\u800c\u9ad8\u901f\u7db2\u8def\u7528\u786c\u9ad4\u8a2d\u8a08
\u5e38\u898b\u8edf\u4f53\u6709:unix slirp,linux IPtable,FreeBSD NATD,MS ics,Win95 Sygate
\u5e38\u898b\u786c\u9ad4\u6709ip\u5206\u4eab\u5668(nat\u786c\u9ad4\u6216PAT+hub\u6216switch),router
\u61c9\u7528:
\u57fa\u672c\u7684private ip\u8f49\u63db\u6210public ip
tcp\u8ca0\u8f09\u5e73\u8861,\u76ee\u7684\u5730\u5740\u8f49\u63dbNAT\u53ef\u4ee5\u91cd\u5b9a\u5411\u4f3a\u670d\u5668\u7684\u9023\u63a5\u5230\u5167\u90e8\u5176\u4ed6\u7684\u4f3a\u670d\u5668
\u8655\u7406\u91cd\u8907\u7684\u7db2\u8def\u4f4d\u5740
\u8b93proxy\u5177\u6709\u900f\u901a\u6027<\/p>\n\n\n\n
nat\u7684\u512a\u9ede
Increases flexibility when connecting to the Internet(\u63d0\u9ad8\u9023\u5230\u7db2\u8def\u7684\u9748\u6d3b\u6027),\u63dbisp\u6642\u53ef\u4e0d\u7528\u70ba\u9700\u8981\u5c0d\u5916\u5b58\u53d6\u7684pc\u6307\u5b9a\u65b0ip
Conserves legally registered addresses(\u4fdd\u7559\u5df2\u8a3b\u518a\u7684\u5408\u6cd5ip),\u4f7f\u7528PAT\u53ef\u8b93\u5167\u90e8pc\u5c0d\u61c9\u4e00\u500bpublic ip
Reduces address overlap occurrence(\u6e1b\u5c11\u4f4d\u7f6e\u91cd\u8986)
Protects network security(\u4fdd\u8b77\u7db2\u8def\u5b89\u5168),\u56e0\u70ba\u5167\u7db2\u8cc7\u8a0a\u4e0d\u6703\u88ab\u5411\u5916\u64ad\u9001<\/p>\n\n\n\n
nat\u7684\u7f3a\u9ede
\u9664\u932f\u9ebb\u7169:
Certain applications will not function(\u67d0\u4e9b\u61c9\u7528\u7121\u6cd5\u4f7f\u7528)
\u3000\u7279\u5225\u662f\u4e00\u4e9b\u901a\u8a0a\u5354\u5b9a\u6216\u61c9\u7528\u7a0b\u5f0f\u4e2d,\u6d89\u53ca\u5230\u5fc5\u9808\u5728IP\u7684payload\u4e2d\u593e\u5e36IP address\u8cc7\u8a0a\u6642
\u3000\u4e00\u822c\u7684NAT\u5be6\u4f5c\u6703\u4fee\u6539\u51fa\u73fe\u5728FTP\u548cICMP\u901a\u8a0a\u5354\u5b9a\u8cc7\u6599\u4e2d\u7684IP address, \u4f46\u5176\u5b83\u5354\u5b9a\u5c31\u4e0d\u4e00\u5b9a\u4e86
\u3000NAT\u8a2d\u5099\u5c07\u9700\u8981\u652f\u63f4\u4e00\u4e9b\u984d\u5916\u7684\u529f\u80fd,\u624d\u53ef\u4ee5\u89e3\u6c7a
Causes loss of end-to-end IP traceability(\u9ede\u5c0d\u9ede\u7684ip\u7121\u6cd5\u8ffd\u8e64)
\u3000\u4ee5IP address\u4f5c\u70ba\u5b89\u5168\u6aa2\u67e5\u7684\u65b9\u5f0f\u5c07\u4e0d\u53ef\u884c
\u3000\u8981\u8ffd\u8e64\u4e00\u500b\u6b77\u7d93\u8a31\u591a\u500b\u5c01\u5305\u5730\u5740\u8f49\u63db\u4e26\u8de8\u8d8a\u8a31\u591a\u500bNAT\u7bc0\u9ede\u7684\u5c01\u5305\u6703\u8b8a\u5f97\u975e\u5e38\u56f0\u96e3
\u3000\u4f46\u662f\u99ed\u5ba2\u60f3\u8981\u7aba\u63a2\u5f97\u77e5\u5c01\u5305\u7684\u8d77\u59cb\u6216\u76ee\u7684\u5730\u5740\u5c07\u975e\u5e38\u96e3\u4ee5\u8ffd\u8e64
\u5f71\u97ff\u901f\u5ea6:
increase delays(\u589e\u52a0\u5ef6\u9072)
\u3000\u56e0\u70ba\u91dd\u5c0d\u6bcf\u4e00\u500b\u5c01\u5305\u6a19\u982d\u7684IP\u5730\u5740\u9032\u884c\u8f49\u63db,\u6240\u4ee5\u6703\u5e36\u4f86\u4e00\u4e9b\u4ea4\u63db\u8def\u5f91\u7684\u5ef6\u9072
\u3000\u7b2c\u4e00\u500b\u5c01\u5305\u662f\u4f9dprocess-switched(\u7a0b\u5e8f\u4ea4\u63db)\u7684\u65b9\u5f0f,\u6703\u900f\u904eslow path(\u7de9\u6162\u8def\u5f91)\u4f86\u50b3\u905e
\u3000ps:\u5982\u679c\u5feb\u53d6\u9805\u76ee\u5b58\u5728\u6642,\u5269\u9918\u7684\u5c01\u5305\u5c07\u6703\u6cbf\u8457fast-switched path(\u5feb\u901f\u4ea4\u63db\u7684\u8def\u5f91)\u4f86\u50b3\u905e
performance may be a consideration(\u8981\u8003\u616e\u6548\u80fd)
\u3000\u56e0NAT\u7528process-switched\u7684\u65b9\u5f0f\u904b\u4f5c,\u6703\u8017\u7528\u6548\u80fd
\u3000CPU\u5c07\u67e5\u770b\u6bcf\u4e00\u500b\u5c01\u5305\u4f86\u6c7a\u5b9a\u662f\u5426\u9700\u8981\u9032\u884c\u5730\u5740\u8f49\u63db,\u4e26\u53ef\u80fd\u4fee\u6539IP\u6a19\u982d\u6216TCP\u6a19\u982d\u7684\u5167\u5bb9<\/p>\n\n\n\n
………………. Dynamic NAT PAT(Port Address Translation,\u7aef\u53e3\u5730\u5740\u8f49\u63db) NAT(Network Address Translatio …<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"fifu_image_url":"","fifu_image_alt":"","_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[10],"tags":[],"class_list":["post-431","post","type-post","status-publish","format-standard","hentry","category-securitysloution"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/posts\/431","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/comments?post=431"}],"version-history":[{"count":0,"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/posts\/431\/revisions"}],"wp:attachment":[{"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/media?parent=431"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/categories?post=431"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/tags?post=431"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
nat\u53ef\u7d30\u5206\u5982\u4e0b:
Static NAT
<\/strong>\u70ba\u56fa\u5b9a\u7684\u4e00\u5c0d\u4e00\u5c0d\u61c9\uff0c\u8ca0\u8f09\u6700\u8f15
<\/strong>\u5167\u90e8\u7db2\u8def\u4e3b\u6a5f\u6c38\u4e45\u5c0d\u61c9\u5230\u4e00\u500b\u5c0d\u5916\u7684IP\u4f4d\u5740
private IP\u4e2d\u7684\u5176\u5b83\u6a5f\u5668\u80fd\u5229\u7528public IP address\u4f86\u5c0d\u5916\u7576\u4f5c server<\/p>\n\n\n\n
<\/strong>\u8f49\u63db\u8868\u52d5\u614b\u5efa\u7acb\u4e00\u5c0d\u4e00\u5c0d\u61c9,\u53ef\u4ee5\u7d66\u5b9a\u4e00\u500b\u7bc4\u570d\u7684Pool\uff0cPrivate\u8207\u5408\u6cd5IP\u9593\u53ef\u4ee5\u52d5\u614b\u6307\u5b9a
\u5167\u90e8\u7db2\u8def\u4e3b\u6a5f\u5728\u9700\u8981\u8207\u5916\u754c\u6e9d\u901a\u6642\uff0c\u5f9e\u4e00\u6bb5\u53ef\u7528\u7684IP\u4f4d\u5740\u4e2d\uff0c\u5f97\u5230\u5176\u4e2d\u4e4b\u4e00
private IP\u7684\u6a5f\u5668\u7121\u6cd5\u7576server, \u8b93\u5916\u9762\u7684\u6a5f\u5668\u9023\u9032\u4f86<\/p>\n\n\n\n
\u4e5f\u7a31\u591a\u91cd\u52d5\u614b\u4f4d\u5740\u8f49\u63db,\u5fa9\u7528\u52d5\u614b\u4f4d\u5740\u8f49\u63db,NAPT(network address and port translation),nat overloading
\u70ba\u4e00public ip\u5c0d\u61c9\u591aprivate ip\u65b9\u5f0f,\u53ef\u8b93\u5167\u90e8\u591a\u53f0\u96fb\u8166\u540c\u6642\u4f7f\u7528public ip\u5b58\u53d6\u7db2\u8def\u4e0a\u7684\u670d\u52d9
\u4f7f\u7528source port number\u4f86\u5340\u5225\u4e0d\u540cprivate ip\u7684\u8f49\u63db
\u7406\u8ad6\u4e0a\u53ef\u652f\u63f465536\u500bprivate ip,\u4f46\u6263\u9664\u4f7f\u7528\u4e2d\u7684port,\u5be6\u969b\u53ea\u80fd\u652f\u63f4\u7d044000\u500bprivate ip
PAT\u53ef\u7d30\u5206:
dynamic PAT
\u4f7f\u7528IP masquerading(\u507d\u88dd)\u7684\u6280\u8853
\u53ef\u8b93\u67d0\u5340\u57df\u5167\u7684\u591a\u500b\u5ba2\u6236\u7aefpriviate ip\u900f\u904e\u4e00\u500bpublic ip\u5b58\u53d6\u7db2\u8def\u8cc7\u8a0a
static PAT
\u904b\u7528port redirection\u529f\u80fd\u8b93\u5916\u90e8\u7279\u5b9aport\u7684\u5c01\u5305\u8f49\u5230\u5167\u90e8\u7279\u5b9a\u4e3b\u6a5f
\u53ef\u8b93\u591a\u90e8\u4f3a\u670d\u5668\u540c\u6642\u4e0a\u7dda,\u5171\u7528\u4e00\u500bIP\u4f4d\u7f6e
twice NAT
\u548cDNS\u4e00\u8d77\u904b\u4f5c,\u53ef\u8b93\u79c1\u6709\u7db2\u8def\u57f7\u884c\u4f3a\u670d\u7a0b\u5f0f
CAT(cable address translation,\u7e9c\u7dda\u4f4d\u5740\u8f49\u63db)
\u542bNAPT\u529f\u80fd\u5916,\u4e26\u63d0\u4f9b\u89bd\u7dda\u4f9b\u61c9\u5546\u548cnat\u8a2d\u5099\u9593\u7684\u4e92\u52d5\u529f\u80fd
\u5141\u8a31\u4f9b\u61c9\u5546\u5c0dNAT\u8a2d\u5099\u505a\u8a2d\u5b9a\u503c\u7684\u6aa2\u9a57\u548c\u7db2\u8def\u5b58\u53d6\u7684\u63a7\u5236
…………….
nat+ipsec\u53ef\u80fd\u65b9\u5f0f
1,\u5148ipsec \u5728nat\uff1aipsec\u53ea\u6709tunnel\u53ef\u884c
\u56e0\u7528transport\u5728\u7528nat\u6539\u8b8aipheader\u6703\u9020\u6210checksum\u6aa2\u67e5\u932f\u8aa4,\u800ctunnel\u5247\u7522\u751f\u65b0header\u7d66nat\u6539\u8b8a\u76f8\u95dc\u8cc7\u8a0a
2,\u5148nat\u5728ipsec:
\u7f3a\u9ede\u662fIPsec Device\u53ef\u80fd\u7121\u6cd5\u5f97\u77e5NAT\u5f8c\u771f\u6b63\u7684\u5c01\u5305\u4f86\u6e90,\u5efa\u8b70\u662f\u5c07NAT\u8207IPsec\u5efa\u7f6e\u5728\u540c\u4e00\u500b\u8a2d\u5099\u4e2d<\/p>\n","protected":false},"excerpt":{"rendered":"