{"id":770,"date":"2008-09-05T11:38:00","date_gmt":"2008-09-05T03:38:00","guid":{"rendered":"http:\/\/note.systw.net\/note\/?p=770"},"modified":"2023-11-05T11:53:50","modified_gmt":"2023-11-05T03:53:50","slug":"ipv4-addressing","status":"publish","type":"post","link":"https:\/\/systw.net\/note\/archives\/770","title":{"rendered":"IPv4 Addressing"},"content":{"rendered":"\n

ipv4\u4f9d\u985e\u5225\u5206\u70ba
classful(\u5206\u7d1a\u5b9a\u5740),\u65e9\u671f\u7684\u65b9\u6cd5,\u5c07ip\u5206\u70baclass A,B,C,D,E
classless(\u4e0d\u5206\u7d1a\u5b9a\u5740),\u4f7f\u7528CIDR\u6280\u8853,\u65b0\u7684\u65b9\u6cd5,\u652f\u63f4vlsm,discontiguous network<\/p>\n\n\n\n

\u70ba\u5340\u5206\u4e0d\u540c\u898f\u6a21\u7684\u7db2\u8def,\u5c07\u6bcf\u500b\u5b8c\u6574\u768432bit\u7684ip\u5206\u6210\u7db2\u8def\u8207\u4e3b\u6a5f\u90e8\u4efd,\u5982\u4e0b\u8868:<\/p>\n\n\n\n

class<\/td>2\u9032\u4f4d\u958b\u982d<\/td>\u7bc4\u570d<\/td>\u7db2\u8defbit\/\u53ef\u7528\u7db2\u8def<\/td>\u4e3b\u6a5fbit\/\u53ef\u7528\u4e3b\u6a5f<\/td>\u5176\u4ed6\u88dc\u5145<\/td><\/tr>
A<\/td>0<\/td>1-126<\/td>8\/127((2^7)-1)<\/td>24\/16,777,216<\/td>\u79c1\u6709ip:10.0.0.0-10.255.255.255<\/td><\/tr>
B<\/td>10<\/td>128-191<\/td>16\/16,384(2^14)<\/td>16\/65,534<\/td>\u79c1\u6709ip:172.16.0.0-172.31.255.255<\/td><\/tr>
C<\/td>110<\/td>192-223<\/td>24\/2,097,152(2^21)<\/td>8\/254<\/td>\u79c1\u6709ip:192.168.0.0-192.168.255.255<\/td><\/tr>
D<\/td>1110<\/td>224-239<\/td> <\/td> <\/td>\u7279\u6b8a\u7528,multicast\u7528(\u8996\u8a0a\u6703\u8b70)<\/td><\/tr>
E<\/td>1111<\/td>240-255<\/td> <\/td> <\/td>\u4fdd\u7559\u7bc4\u570d,IETF\u7814\u7a76\u7db2\u8def\u7528<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

ps:
Class A addresses:127*16,777,214= 2,130,706,178
Class B addresses:16384* 65,534 = 1,073,709,056
Class C addresses:2,097,152*254 = 532,676,608
total available addresses=
2,130,706,178 + 1,073,709,056+532,676,608 =
3,737,091,842<\/p>\n\n\n\n

CIDR(Classless Inter-Domain Routing,\u4e0d\u5206\u7d1a\u7db2\u57df\u9593\u4e4b\u8def\u7531)
\u7531IETF\u63d0\u51fa
\u4e0d\u5206\u7b49\u7d1aIP,\u5b8c\u5168\u4f9d\u7167mask\u5b9a\u7fa9\u7db2\u8def
\u53ef\u5c07\u591a\u500bSUBNET\u6216\u662fNETWORK\u5408\u8d77\u4f86\u6210\u70ba\u4e00\u500bsupernet
\u53ef\u4f7f\u7528VLSM\u6c7a\u5b9a\u53ef\u8b8a\u9577\u5ea6\u7684netmask\u4f86\u7522\u751f\u8a31\u591asubnet
\u642d\u914d\u62d3\u6a38\u5f0f\u5b9a\u5740\u6cd5,\u5ba2\u6236\u53ef\u4f9d\u5be6\u969b\u9700\u6c42\u53d6\u5f97\u9069\u7576\u5927\u5c0f\u4f4d\u5740\u5340\u584a<\/p>\n\n\n\n

mask
\u7528\u4f86\u6c7a\u5b9a\u7db2\u8def\u4f4d\u7f6e\u8207\u4e3b\u6a5f\u4f4d\u7f6e\u7528\u7684\u53c3\u6578,\u5982\u4e0b\u8868:<\/p>\n\n\n\n

10\u9032\u4f4dmask<\/td>2\u9032\u4f4dmask,\u9810\u8a2d\u7db2\u8def\u4f4d\u5143\u70ba1,\u4e3b\u6a5f\u4f4d\u5143\u70ba0<\/td>CIDR\u503c<\/td>\u7db2\u8defbit<\/td>\u53ef\u7528\u4e3b\u6a5f<\/td>\u5176\u4ed6\u88dc\u5145<\/td><\/tr>
255.0.0.0<\/td>11111111,00000000,00000000,00000000<\/td>\/8<\/td>8<\/td>16,777,216<\/td>\u7d66class a\u7576\u9810\u8a2dmask<\/td><\/tr>
255.255.0.0<\/td>11111111,11111111,00000000,00000000<\/td>\/16<\/td>16<\/td>65536<\/td>\u7d66class b\u7576\u9810\u8a2dmask<\/td><\/tr>
255.255.255.0<\/td>11111111,11111111,11111111,00000000<\/td>\/24<\/td>24<\/td>256<\/td>\u7d66class c\u7576\u9810\u8a2dmask<\/td><\/tr>
255.255.255.128<\/td>11111111,11111111,11111111,10000000<\/td>\/25<\/td>25<\/td>128<\/td><\/td><\/tr>
255.255.255.192<\/td>11111111,11111111,11111111,11000000<\/td>\/26<\/td>26<\/td>64<\/td><\/td><\/tr>
255.255.255.224<\/td>11111111,11111111,11111111,11100000<\/td>\/27<\/td>27<\/td>32<\/td><\/td><\/tr>
255.255.255.240<\/td>11111111,11111111,11111111,11110000<\/td>\/28<\/td>28<\/td>16<\/td><\/td><\/tr>
255.255.255.248<\/td>11111111,11111111,11111111,11111000<\/td>\/29<\/td>29<\/td>8<\/td><\/td><\/tr>
255.255.255.252<\/td>11111111,11111111,11111111,11111100<\/td>\/30<\/td>30<\/td>4<\/td>\u7528\u5728\u9ede\u5c0d\u9ede\u7684wan\u93c8\u8def<\/td><\/tr>
255.255.255.254<\/td>11111111,11111111,11111111,11111110<\/td>\/31<\/td>31<\/td>2<\/td><\/td><\/tr>
255.255.255.255<\/td>11111111,11111111,11111111,11111111<\/td>\/32<\/td>32<\/td>1<\/td>\u4e3b\u6a5f\u81ea\u5df1\u672c\u8eab<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

\u4e3b\u6a5f\u6578-2=\u5be6\u969b\u53ef\u7528\u4e3b\u6a5f\u6578
ps:mask\u82e5\u70ba0.0.0.0,\u5728\u8def\u7531\u8868\u4e0a\u4ee3\u8868\u4efb\u4f55\u4e3b\u6a5f<\/p>\n\n\n\n

RFC3330\u5b9a\u7fa9\u7684\u4fdd\u7559\u4f4d\u7f6e<\/strong>
0.0.0.0\/8 \u6b64\u4f4d\u5740\u8868\u793a\u6240\u6709\u4efb\u4f55\u7684\u610f\u601d
\u3000\u5728netstat\u4e2d,\u8868\u793a\u61c9\u7528\u7a0b\u5f0f\u5c07\u63a5\u807d\u6240\u6709\u7684\u672c\u6a5f\u4ecb\u9762
\u3000Used for broadcast messages to the current (“this”) network,by RFC 1700
100.64.0.0\/10, refer RFC 6598
127.0.0.0\/8  \u7528\u505aloopback(\u8ff4\u8def)\u6e2c\u8a66\u7528
169.254.0.0\/16 dhcp\u7a0b\u5e8f\u5931\u6557\u6642\uff0c\u4e3b\u6a5f\u9810\u8a2d\u4f7f\u7528\u7684IP\u4f4d\u7f6e
192.0.2.0\/24 \u4fdd\u7559\u4f5c\u70ba\u6587\u4ef6\u53ca\u793a\u7bc4\u7528\u9014
192.88.99.0\/24 \u7528\u65bcIPv4\u548cIPv6\u4e2d\u7e7c(RFC3068)
192.18.0.0\/15 \u7528\u65bc\u7db2\u8def\u8a2d\u5099\u6e2c\u8a66(RFC2544)
refer
https:\/\/tools.ietf.org\/html\/rfc3330
https:\/\/en.wikipedia.org\/wiki\/Reserved_IP_addresses<\/p>\n\n\n\n

\u5176\u4ed6\u7279\u6b8aip\u4f4d\u5740
\u7db2\u8def\u4f4d\u5143\u51680+\u4e3b\u6a5f\u4f4d\u5143\u51680:0.0.0.0,\u672c\u6a5f,\u7cfb\u7d71\u555f\u52d5\u7528,\u8def\u7531\u8868\u7528\u5b83\u4f86\u6307\u5b9a\u9810\u8a2d\u8def\u5f91,\u4e5f\u53ef\u89e3\u91cb\u70ba\u4efb\u4f55\u7db2\u8def
\u7db2\u8def\u4f4d\u5143\u51681+\u4e3b\u6a5f\u4f4d\u5143\u51681:255.255.255.255,\u81ea\u5df1\u7684\u7db2\u8def\u5ee3\u64ad\u4f4d\u5740,\u4e5f\u53eb\u505aflooded broadcast
\u7db2\u8def\u4f4d\u5143+\u4e3b\u6a5f\u4f4d\u5143\u51681:\u7279\u5b9a\u7db2\u8def\u7684\u5ee3\u64ad\u4f4d\u5740,\u4e5f\u53eb\u505adirected broadcast
\u7db2\u8def\u4f4d\u5143+\u4e3b\u6a5f\u4f4d\u5143\u51680:\u8a72\u7db2\u8def\u7684\u4f4d\u5740

\u7b97ip\u7684\u7db2\u8def\u4f4d\u5740\u548c\u5ee3\u64ad\u4f4d\u5740
1\u5c07mask\u8f49\u62102\u9032\u4f4d
2ip\u5728mask\u975e0\u90e8\u4efd\u6539\u586b0,\u91cd\u7b97\u5f8c=\u7db2\u8def\u4f4d\u7f6e,\u5c31\u662fmask\u548cip\u505aand\u904b\u7b97
3ip\u5728mask\u975e0\u90e8\u4efd\u6539\u586b1,\u91cd\u7b97\u5f8c=\u5ee3\u64ad\u4f4d\u7f6e,\u5c31\u662fmask\u5148not\u5f8c\u5728\u548cip\u505aor\u904b\u7b97
ex:ip=192.128.248.130,mask=255.255.255.240
11111111,11111111,11111111,11110000(255.255.255.240)
11000000.10000000.11111000.10000010(192.128.248.130)
11000000.10000000.11111000.10000000(192.128.248.128)\u7db2\u8def\u4f4d\u7f6e=ip AND mask
11000000.10000000.11111000.10001111(192.128.248.143)\u5ee3\u64ad\u4f4d\u7f6e=ip OR (not(mask))

……………

subnet(\u5b50\u7db2\u8def)
\u5f9e\u4e00\u500b\u7db2\u8def\u5207\u5272\u7522\u751f
\u597d\u8655:\u6e1b\u5c11\u7db2\u8def\u6d41\u91cf; \u5f48\u6027\u5206\u914d\u904b\u7528; \u7c21\u5316\u7ba1\u7406; \u5b89\u5168\u8003\u91cf

subneting(\u5b50\u7db2\u8def\u5207\u5272)
\u53ef\u5c07\u4e00\u500bNETWORK\u5207\u6210\u591a\u500bSUBNET
\u65b9\u6cd5:\u5411\u5f8c\u501fbit,\u6703\u4f7f\u7db2\u8def\u8b8a\u591a,\u4f46\u5404\u7db2\u5167\u4e3b\u6a5f\u8b8a\u5c11
\u3000class c\u6700\u591a\u53ef\u5411\u5f8c\u501f6bit\u5efa\u7acb64\u500b\u5b50\u7db2\u8def
\u3000class b\u6700\u591a\u53ef\u5411\u5f8c\u501f14bit\u5efa\u7acb16384\u500b\u5b50\u7db2\u8def
\u3000class a\u6700\u591a\u53ef\u5411\u5f8c\u501f22bit\u5efa\u7acb4194304\u500b\u5b50\u7db2\u8def
ex:a\u7db2\u898160\u500bip,b\u7db2\u898130\u500bip,c\u7db2\u89812\u500bip,d\u7db2\u898110\u500bip
\u7528192.168.10.0\u7db2\u8def\u4f86\u5207\u5272,\u53ef\u5207\u6210\u5982\u4e0b
192.168.10.0\/26,\u5340\u584a\u5927\u5c0f\u70ba64,\u670962\u500bip\u7d66a\u7db2
192.168.10.64\/26,\u5340\u584a\u5927\u5c0f\u70ba64,\u670962\u500bip\u7d66b\u7db2
192.168.10.128\/26,\u5340\u584a\u5927\u5c0f\u70ba64,\u670962\u500bip\u7d66c\u7db2
192.168.10.192\/26,\u5340\u584a\u5927\u5c0f\u70ba64,\u670962\u500bip\u7d66d\u7db2

VLSM(Variable Length Subnet Mask,\u53ef\u8b8a\u5b50\u7db2\u8def\u5207\u5272) ,RFC1219
\u9019\u662f\u4e00\u7a2e\u7522\u751f\u4e0d\u540c\u5927\u5c0f\u5b50\u7db2\u7684\u7db2\u7d61\u5206\u914d\u6a5f\u5236,\u53ef\u4f7fIP\u7684\u53ef\u7528\u6027\u589e\u52a0
ex:a\u7db2\u898160\u500bip,b\u7db2\u898130\u500bip,c\u7db2\u89812\u500bip,d\u7db2\u898110\u500bip
\u7528192.168.10.0\u7db2\u8def\u4f86\u5207\u5272,\u53ef\u5207\u6210\u5982\u4e0b
192.168.10.0\/26,\u5340\u584a\u5927\u5c0f\u70ba64,\u670962\u500bip\u7d66a\u7db2
192.168.10.64\/27,\u5340\u584a\u5927\u5c0f\u70ba32,\u670930\u500bip\u7d66b\u7db2
192.168.10.96\/30,\u5340\u584a\u5927\u5c0f\u70ba4,\u67092\u500bip\u7d66c\u7db2
192.168.10.100\/28,\u5340\u584a\u5927\u5c0f\u70ba16,\u670914\u500bip\u7d66d\u7db2
\u9084\u6709\u5340\u584a\u5927\u5c0f140\u672a\u5206\u914d,\u53ef\u5728\u7522\u751f\u5176\u4ed6\u5b50\u7db2\u8def

……………………

summariz(\u7e3d\u7d50),\u4e5f\u7a31route aggregation(\u8def\u5f91\u805a\u5408)
\u5c07\u591a\u500b\u7db2\u8def\u96c6\u5408\u6210\u5927\u7684\u7db2\u8def,\u4e5f\u7a31\u70basupernet(\u8d85\u7db2\u8def)
\u65b9\u6cd5:\u5411\u524d\u501fbit,\u6703\u4f7f\u7db2\u8def\u8b8a\u5c11,\u4f46\u5404\u7db2\u4e3b\u6a5f\u8b8a\u591a
\u9019\u8b93\u7e5e\u9001\u5354\u5b9a\u80fd\u5920\u4ee5\u4e00\u500b\u4f4d\u5740\u4f86\u5ba3\u50b3\u591a\u500b\u7db2\u8def
\u76ee\u7684\u662f\u70ba\u4e86\u7e2e\u6e1b\u8def\u7531\u5668\u4e4b\u8def\u5f91\u8868\u7684\u5927\u5c0f,\u4ee5\u7bc0\u7701\u8a18\u61b6\u9ad4,\u540c\u6642\u7e2e\u77edip\u5206\u6790\u8def\u5f91\u8868\u4ee5\u627e\u5c0b\u627a\u9054\u9060\u7aef\u7db2\u8def\u4e4b\u8def\u5f91\u6642\u9593
\u7c4d\u7531\u5728\u4e00\u500b\u5ba3\u50b3\u8a0a\u606f\u4e2d\u5ba3\u50b3\u8a31\u591a\u8def\u5f91,\u800c\u975e\u5404\u5225\u7684\u5ba3\u50b3\u6bcf\u689d\u8def\u5f91,\u53ef\u6700\u6709\u6548\u7387\u63d0\u4f9b\u8def\u5f91\u66f4\u65b0,\u9019\u6703\u7bc0\u7701\u4e0d\u5c11\u983b\u5bec
ps:isp\u9023\u5230\u5ba2\u6236\u7aef\u7db2\u57df\u6642\u5e38\u7528\u6b64\u65b9\u6cd5
ex:\u82e5\u8def\u7531\u8868\u670910.1.0.0\/24\u523010.1.3.0\/24\u90194\u500b\u7db2\u8def,\u4e14\u90fd\u6703\u9001\u523010.10.0.0\u7db2\u8def
\u5247\u90194\u500b\u7db2\u8def\u53efsummariz\u621010.1.0.0\/22,\u4e26\u5f9e\u523010.10.0.0\u7db2\u8def,\u8def\u5f91\u5c31\u5f9e4\u7b46\u8b8a\u62101\u7b46
\u9019\u540c\u6642\u4e5f\u8868\u793a,10.1.0.0\u523010.1.3.255\u76841024\u500bip,\u6703\u9001\u523010.10.0.0\u7684\u7db2\u8def
ex:\u82e5\u8def\u7531\u8868\u6709192.168.144.0\/21\u548c192.168.152.0\/21\u90192\u500b\u7db2\u8def\u6703\u88ab\u9001\u5230s0\u4ecb\u9762
\u5247\u90192\u500b\u7db2\u8def\u53efsummariz\u6210192.168.144.0\/20,\u4e26\u9001\u5230s0\u4ecb\u9762,\u8def\u5f91\u5f9e2\u7b46\u8b8a\u62101\u7b46
\u9019\u540c\u6642\u4e5f\u8868\u793a192.168.144.0\u5230192.168.159.255\u7684ip\u6703\u88ab\u9001\u5230s0\u4ecb\u9762<\/p>\n","protected":false},"excerpt":{"rendered":"

ipv4\u4f9d\u985e\u5225\u5206\u70baclassful(\u5206\u7d1a\u5b9a\u5740),\u65e9\u671f\u7684\u65b9\u6cd5, …<\/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":[25],"tags":[],"class_list":["post-770","post","type-post","status-publish","format-standard","hentry","category-osi-layer3"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/posts\/770","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=770"}],"version-history":[{"count":0,"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/posts\/770\/revisions"}],"wp:attachment":[{"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/media?parent=770"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/categories?post=770"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/tags?post=770"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}