ethernet(\u4e59\u592a\u7db2\u8def)
IEEE\u4ee3\u865f\u70ba802.3
ethernet\u7684\u6210\u529f\u5728\u65bc\u5176\u7c21\u6613\u6027,\u7dad\u8b77\u5bb9\u6613,\u8207\u65b0\u6280\u8853\u7d50\u5408\u4e4b\u80fd\u529b,\u53ef\u9760\u6027\u53ca\u4f4e\u6210\u672c\u5b89\u88dd\u8207\u5347\u7d1a\u4e4b\u7d50\u679c
\u908f\u8f2f\u62d3\u6a38\u70babus(\u532f\u6d41\u6392)\u6280\u8853
\u50b3\u905e\u5f62\u5f0f\u70babroadcast(\u5ee3\u64ad)
media access control\u5c6c\u65bcnondeterministic
\u5b58\u53d6\u65b9\u5f0f:1-persistent CSMA\/CD
\u7de8\u78bc\u65b9\u5f0f:manchester<\/p>\n\n\n\n
\u7f3a\u9ede\uff1a
\u9ad8\u8ca0\u8f09\u6642\u983b\u5bec\u4f7f\u7528\u7387\u4f4e\uff1a\u7db2\u8def\u8ca0\u8f09\u91cd\u6642\u6703\u56e0\u70ba\u4e0d\u65b7\u767c\u751f\u8a0a\u6846\u885d\u649e\u7684\u73fe\u8c61\u800c\u4f7f\u5f97\u8a0a\u6846\u7121\u6cd5\u6210\u529f\u7684\u50b3\u9001
\u4e0d\u63d0\u4f9b\u4fdd\u8a3c\u50b3\u9001\u5ef6\u9072\u670d\u52d9:\u82e5\u4e0d\u65b7\u767c\u751f\u885d\u649e\u7684\u73fe\u8c61\u800c\u4f7f\u5f97\u8a0a\u6846\u5c07\u7121\u6cd5\u88ab\u6210\u529f\u50b3\u9001\u51fa\u53bb
\u983b\u5bec\u4f7f\u7528\u4e0d\u4fdd\u8a3c\u516c\u5e73\uff1a\u6c92\u6709\u8f2a\u6d41\u50b3\u9001\u7684\u7279\u6027\uff0c\u56e0\u6b64\u5404\u5de5\u4f5c\u7ad9\u4f7f\u7528\u7684\u983b\u5bec\u53ef\u80fd\u5dee\u7570\u6975\u5927
\u512a\u9ede\uff1a
\u7db2\u8def\u5bb9\u932f\u6027\u9ad8,\u6210\u672c\u4f4e,\u666e\u53ca,\u8a2d\u5b9a\u5b89\u88dd\u6613<\/p>\n\n\n\n
ps:
ethernet half-duplex\u5be6\u969b\u50b3\u8f38\u901f\u5ea6\u7d04\u70ba\u7406\u8ad6\u4e0a\u768450~60%
ps:
Ethernet typically is not used at either the distribution or the core layer due to its relatively low bandwidth capacity
ps:
collision domain(\u78b0\u649e\u9818\u57df):\u6b64\u9818\u57df\u7684\u7bc0\u9ede\u53ef\u807d\u5230\u6b64\u9818\u57df\u7684\u6240\u6709\u8a0a\u865f,\u4e14\u6b64\u9818\u57df\u662f\u4e00\u500blan segment
broadcast domain(\u5ee3\u64ad\u9818\u57df):\u6b64\u9818\u57df\u7684\u7bc0\u9ede\u5728\u5ee3\u64ad\u7bc4\u570d\u5167,\u4e14\u6b64\u9818\u57df\u662f\u4e00\u500blan<\/p>\n\n\n\n
nondeterministic(\u975e\u660e\u78ba\u6027)
\u4f7f\u7528first-come first-served(\u5148\u5230\u5148\u670d\u52d9)\u65b9\u5f0f
\u6216\u7a31probabilistic(\u53ef\u80fd\u6027\u7684)\u6a21\u5f0f\u7684\u5354\u5b9a,\u4e0d\u4fdd\u8b49\u5de5\u4f5c\u7ad9\u53ef\u7372\u5f97\u63a5\u901a\u7db2\u7dda\u7684\u80fd\u529b
ex:csma\/cd<\/p>\n\n\n\n
…………………………………………. \u95dc\u65bcIEEE802.3\u548cdix\/ethernet2\u7684frame<\/strong> frame\u7684\u6f14\u9032 ………………………………………….<\/p>\n\n\n\n \u78b0\u649e\u7684\u7d50\u679c<\/strong> <\/p>\n\n\n\n late collision:\u8a0a\u6846\u5df1\u50b3\u9001\u524d64\u4f4d\u5143\u5f8c\u624d\u767c\u751f\u7684\u78b0\u649e ……………………………………………<\/p>\n\n\n\n \u4e59\u592a\u7db2\u8def\u4e2d\u6240\u8a8d\u5b9a\u7684\u932f\u8aa4\u5305\u62ec: jabber(\u7121\u610f\u7fa9\u8a0a\u6846):\u5b9a\u7fa9\u5728802.3\u6a19\u6e96\u4e2d,\u6700\u5c11\u50b3\u8f38\u7684\u671f\u9593\u70ba20.000\u523050.000\u4f4d\u5143\u6642\u9593 ethernet(\u4e59\u592a\u7db2\u8def)IEEE\u4ee3\u865f\u70ba802.3ethe …<\/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":[26],"tags":[],"class_list":["post-797","post","type-post","status-publish","format-standard","hentry","category-osi-layer2"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/posts\/797","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=797"}],"version-history":[{"count":0,"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/posts\/797\/revisions"}],"wp:attachment":[{"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/media?parent=797"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/categories?post=797"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/systw.net\/note\/wp-json\/wp\/v2\/tags?post=797"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
\u6578\u64da\u4ee5frame(\u8a0a\u6846)\u5f62\u5f0f\u50b3\u905e<\/strong>
1frame\u9001\u51fa\u5f8c\u6703\u4ee5\u96fb\u5b50\u4fe1\u865f\u540c\u6642\u5411bus\u5169\u7aef\u5ee3\u64ad,\u5404\u7bc0\u9ede\u7686\u6536\u5230
2\u5404\u7bc0\u9ede\u6aa2\u67e5\u76ee\u5730\u4f4d\u7f6e\u4ee5\u5224\u65b7\u662f\u5426\u8981\u63a5\u6536,\u82e5\u662f\u6846\u5305\u5c07\u8907\u88fd\u4e00\u4efd\u7d66\u81ea\u5df1
3\u539f\u4f86\u6846\u5305\u7e7c\u7e8c\u9001\u7d66\u4e0b\u4e00\u7bc0\u9ede\ufe50\u76f4\u5230\u5c01\u5305\u62b5\u9054\u7d42\u7aef\u96fb\u963b\u624d\u6703\u88ab\u92b7\u6bc0\u3002<\/p>\n\n\n\n
\u4e59\u592a\u7db2\u8def\u7531xerox\u6240\u767c\u660e\u7684baseband lan specification(\u57fa\u983b\u5340\u57df\u7db2\u8def\u898f\u7bc4),\u4e14\u7531dix(dec,intel,xerox)\u5171\u540c\u958b\u767c
IEEE802.3\u6a19\u6e96\u6240\u63cf\u8ff0\u7684\u662f\u4fee\u6539\u904e\u7684\u539f\u59cb\u4e59\u592a\u7db2\u8def\u6a19\u6e96
\u5728dix\/ethernet2\u53caIEEE802.3\u898f\u683c\u9593\u4ecd\u5b58\u5728\u4e00\u4e9b\u6975\u5c0f\u7684\u5dee\u7570,\u5982\u4e0b:
\u3000dix\/ethernet2 frame\u683c\u5f0f:[preamble][da][sa][type][data][fcs]
\u3000IEEE802.3 frame\u683c\u5f0f:[preamble][da][sa][length][data][fcs]
\u800c\u4e14IEEE802.3frame\u6703\u52a0\u5165LLC header\u5230data\u6b04\u4f4d
\u56e0\u70baIEEE802.3\u7121type\u6240\u4ee5\u7121\u6cd5\u8b58\u5225\u4e0a\u5c64\u5354\u5b9a,\u6240\u4ee5IEEE\u5b9a\u7fa9802.2LLC,\u4ee5\u63d0\u4f9b\u6b64\u529f\u80fd
\u53e6\u5916IEEE802.3frame\u4e2d\u6c92\u6307\u5b9atype\u5247\u4e0a\u5c64\u5354\u5b9a\u9810\u8a2d\u70baipx,\u9019\u662f\u6b77\u53f2\u56e0\u7d20<\/p>\n\n\n\n
Frame\u898f\u683c\u3000<\/strong>
\u5927\u5c0f\u70ba64-1518bytes(\u4e0d\u5305\u542bpreamble)
frame\u6b04\u4f4d\u8aaa\u660e\u5982\u4e0b:
preamble<\/strong>(\u5e8f\u8a00\/\u524d\u7f6e\u8a0a\u865f)8bytes,0\u82071\u4ea4\u5dee\u8b8a\u63db\u7684\u6b04\u4f4d,\u7d66\u63a5\u6536\u8005\u786c\u9ad4\u505a\u8a0a\u865f\u540c\u6b65\u7528,\u7de8\u78bc\u6642\u7522\u751f,\u89e3\u78bc\u6642\u6703\u79fb\u9664
\u65e9\u671f\u7684ieee\u7248\u672c\u4e2d,preamble(8)\u88ab\u62c6\u6210\u524d\u7f6e\u8a0a\u865f(7)\u548cSFD(\u8a0a\u6846\u8d77\u59cb\u7b26\u865f)(1)
\u6700\u5f8c\u4e00\u500bbyte\u662f10101011,\u7a31\u70basfd
100mbps\u6216\u8f03\u9ad8\u50b3\u901f\u5ea6\u7684\u4e59\u592a\u7db2\u8def\u662f\u540c\u6b65\u7684,\u56e0\u6b64\u7528\u4e0d\u5230preamble,\u4f46\u70ba\u4e86\u76f8\u5bb9\u4ecd\u7136\u5b58\u5728
destination<\/strong>(\u76ee\u5730)6byte\u53casource<\/strong>(\u4f86\u6e90)6byte
\u4ee5mac\u4f4d\u5740\u70ba\u4e3b
\u6700\u9ad8\u4f4d\u5143\u70ba0\u8868\u4e00\u822c\u4f4d\u5740
\u6700\u9ad8\u4f4d\u5143\u70ba1\u8868\u7fa4\u7d44\u4f4d\u7f6e(\u5141\u8a31\u591a\u7ad9\u53f0\u76e3\u807d\u55ae\u4e00\u4f4d\u7f6e,\u4e5f\u7a31\u591a\u9ede\u50b3\u9001mutlicast\uff09
\u76ee\u5730\u4f4d\u7f6e\u90fd\u70ba1\u8868\u793a\u5ee3\u64ad
type\/length<\/strong>(\u8a0a\u606f\/\u9577\u5ea6)2byte,\u544a\u8a34\u63a5\u6536\u7aef\u5982\u4f55\u8655\u7406\u8a0a\u6846
\u503c\u6bd41536\u621616\u9032\u4f4d\u76840600\u5c0f\u5247\u4ee3\u8868length,\u5927\u65bc\u5247\u8868type
\u5e38\u898b\u7684type\u67090800\u4ee3\u8868ip,8137\u4ee3\u8868ipx,0600\u4ee3\u8868xns,809b\u4ee3\u8868apple talk,0806\u4ee3\u8868arp
data<\/strong>(\u6578\u64da\u6216PDU)46-1500byte,0\u4f4d\u5143\u8cc7\u6599\u9577\u5ea6\u6703\u9020\u6210\u554f\u984c,\u82e5\u8cc7\u6599bit\u5c0f\u65bc46byte\u5247\u81ea\u52d5\u586b\u585e
\u4e00\u822c\u9084\u6703\u5728\u653e802.2LLC(3byte)\u548c802.2SNAP(5byte),\u6240\u4ee5\u8981\u6263\u63898byte\u624d\u662f\u53ef\u5b58\u653e\u4e0a\u5c64\u5354\u5b9a\u7684\u7a7a\u9593
FCS<\/strong>(frame check sequence)4byte,\u6aa2\u6e2c\u8a0a\u6846,\u4f7f\u7528crc-32,\u50c5\u5075\u6e2c\u4e0d\u4fee\u6b63<\/p>\n\n\n\n
ethernet v1,1980\u7531dix(dec,intel,xeror)\u5236\u5b9a
ethernet v2,1982\u7531dix(dec,intel,xeror)\u5236\u5b9a,\u6700\u5e38\u898b\u7684\u4e59\u592a\u7db2\u8def\u683c\u5f0f
raw 802.3,1983\u7531novell\u7684netware\/86\u6240\u4f7f\u7528\u7684\u79c1\u6709\u4e59\u592a\u7db2\u8def\u683c\u5f0f,\u53ea\u652f\u63f4ipx\/spx,length\u6b04\u4f4d\u7bc4\u570d\u70ba0000-05dc
IEEE802.3,\u7531ethernet v2\u767c\u5c55\u800c\u4f86,\u5728\u8cc7\u6599\u6b04\u4f4d\u52a0\u5165LLC
IEEE802.3+snap,\u70ba\u4e86\u5728LLC\u4e0a\u652f\u63f4\u66f4\u591a\u7684\u4e0a\u5c64\u5354\u8b70\u800c\u767c\u4f48<\/p>\n\n\n\n
\u90e8\u5206\u8207\u640d\u58de\u8a0a\u6846\u4e4b\u9577\u5ea6\u5c0f\u65bc64byte,\u4e14fcs\u90e8\u5206\u4e0d\u5408\u6cd5
\u5df1\u640d\u58de\u6216\u90e8\u4efd\u5df1\u50b3\u8f38\u7684\u8a0a\u606f\u901a\u5e38\u88ab\u8996\u70bacollision fragment(\u78b0\u649e\u7247\u6bb5)\/fragments runt\/runt
\u78b0\u649e\u4f9d\u6b21\u6578\u5206:
single collision(\u55ae\u4e00\u78b0\u649e):\u50b3\u8a0a\u865f\u6642\u767c\u751f\u78b0\u649e,\u4f46\u5728\u7b2c\u4e8c\u6b21\u50b3\u5c31\u6210\u529f
multiple collision(\u591a\u91cd\u78b0\u649e):\u50b3\u8a0a\u865f\u6642\u767c\u751f\u78b0\u649e,\u4e00\u76f4\u5230\u591a\u6b21\u78b0\u649e\u5f8c\u624d\u50b3\u6210\u529f
\u78b0\u649e\u578b\u614b\u5206:
local collision(\u5340\u57df\u78b0\u649e):\u6b63\u5e38\u60c5\u6cc1
remote collision(\u9060\u7aef\u78b0\u649e):\u6b63\u5e38\u60c5\u6cc1
late collision(\u665a\u78b0\u649e):\u932f\u8aa4\u60c5\u6cc1<\/p>\n\n\n\n
nic\u7684\u6676\u7247\u7d44\u4e2d,\u5728\u767c\u751flate collision\u6642,\u4e26\u4e0d\u6703\u81ea\u52d5\u8981\u6c42\u91cd\u65b0\u50b3,
\u9019\u4e9blate collision\u6240\u9020\u6210\u7684\u5ef6\u9072\u7a31\u70baconsumption delay(\u79cf\u8cbb\u5ef6\u9072),\u9019\u4e9b\u5ef6\u9072\u589e\u52a0\u6703\u4f7f\u7db2\u8def\u6548\u80fd\u4e0b\u964d<\/p>\n\n\n\n
<\/strong>\u5728slot time\u7d50\u675f\u524d\u6216\u7d50\u675f\u5f8c\u6240\u767c\u751f\u7684\u540c\u6642\u50b3\u8f38
\u8d85\u904e\u6216\u4e0d\u5408\u6cd5\u8a0a\u6846\u9577\u5ea6\u4e4b\u50b3\u8f38 ex:jabber,long frame,range error
\u4e0d\u5408\u6cd5\u7684\u77ed\u8a0a\u6846 ex:short frame,collision fragment
\u6bc0\u640d\u4e4b\u50b3\u8f38 ex:fcs\u932f\u8aa4
\u6240\u50b3\u8f38\u7684\u4f4d\u5143\u6578\u4e0d\u8db3\u6216\u592a\u591a ex:alignment error
\u8a0a\u6846\u4e2d\u5be6\u969b\u4f4d\u5143\u7d44\u8cc7\u6599\u8207\u901a\u5831\u7684\u4f4d\u5143\u7d44\u8cc7\u6599\u4e0d\u76f8\u7b26 ex:ranage error
\u4e0d\u5c0b\u5e38\u9577\u5ea6\u4e4b\u524d\u7f6e\u8a0a\u865f\u6216\u7121\u610f\u8a0a\u6846\u60c5\u6cc1 ex:ghost,jabber<\/p>\n\n\n\n
long frame(\u9577\u8a0a\u6846):\u8a0a\u6846\u9577\u5ea6\u5927\u65bc\u5408\u6cd5\u9577\u5ea6,\u4e14\u4e0d\u8ad6\u662f\u5426\u52a0\u4e0a\u4e86tag(\u8b58\u5225\u8cc7\u8a0a)\u90fd\u7b97\u5728\u9577\u5ea6\u5167
short frame(\u77ed\u8a0a\u6846)\/frame runt:\u8a0a\u6846\u9577\u5ea6\u5c0f\u65bc\u5408\u6cd5\u7684\u6700\u77ed64byte\u9577\u5ea6,\u4e14\u8a0a\u6846\u5177\u6709\u5b8c\u6574\u7684fcs
alignment error(\u6821\u6e96\u932f\u8aa4):\u8a0a\u606f\u7684\u6240\u6709\u4f4d\u5143\u7121\u6cd5\u88ab8\u6574\u9664,\u901a\u5e38\u7531\u8edf\u9ad4\u6216\u78b0\u649e\u5f15\u8d77,\u4e14\u53ef\u80fd\u6703\u9020\u6210\u7576\u6a5f
range error(\u7bc4\u570d\u932f\u8aa4):\u8a0a\u6846\u4e2d\u9577\u5ea6\u6b04\u4f4d\u7684\u503c\u70ba\u5408\u6cd5\u5927\u5c0f,\u4f46\u537b\u4e0d\u7b26\u5408\u63a5\u6536\u5230\u8a0a\u6846\u7684\u5be6\u969b\u6578\u76ee
ghost:\u5728\u7e9c\u7dda\u4e0a\u6240\u5075\u6e2c\u5230\u7684\u80fd\u91cf,\u96dc\u8a0a<\/p>\n","protected":false},"excerpt":{"rendered":"