Kowa ya san cewa waɗannan bytes shida, yawanci ana nunawa a tsarin hexadecimal, an sanya su zuwa katin sadarwar a masana'anta, kuma suna da alama bazuwar. Wasu mutane sun san cewa bytes uku na farko na adireshin su ne ID na masana'anta, sauran bytes uku kuma an ba su. Hakanan an san cewa zaku iya saita kanku sabani adireshin Mutane da yawa sun ji labarin "adiresoshin bazuwar" a cikin Wi-Fi.
Bari mu gano menene.
Adireshin MAC (adireshin kula da samun damar kafofin watsa labarai) wani keɓaɓɓen mai ganowa ne da aka sanya wa adaftar cibiyar sadarwa, ana amfani da shi a cikin hanyoyin sadarwa na ka'idojin IEEE 802, galibi Ethernet, Wi-Fi da Bluetooth. A hukumance ana kiranta "EUI-48 mai ganowa". Daga sunan a bayyane yake cewa adireshin yana da tsayi 48, watau. 6 bytes. Babu wani ma'auni da aka yarda da shi don rubuta adireshi (saɓanin adireshin IPv4, inda a koyaushe ana raba octets da dige-dige) yawanci ana rubuta su azaman lambobi shida hexadecimal rabu da colon: 00:AB: CD:EF:11: 22, kodayake wasu masana'antun kayan aiki sun fi son bayanin 00 -AB-CD-EF-11-22 har ma da 00ab.cdef.1122.
A tarihi, adiresoshin suna walƙiya a cikin ROM na katin sadarwar kwakwalwar kwakwalwar kwamfuta ba tare da ikon gyara su ba tare da mai sarrafa filasha ba, amma a zamanin yau ana iya canza adireshin ta hanyar shirye-shirye daga tsarin aiki. Kuna iya saita adireshin MAC na katin cibiyar sadarwa da hannu a cikin Linux da MacOS (ko da yaushe), Windows (kusan koyaushe, idan direba ya ba da izini), Android (kafe kawai); Tare da iOS (ba tare da tushen ba) irin wannan dabara ba zai yiwu ba.
Tsarin adireshin
Adireshin ya ƙunshi ɓangaren mai ganowa na masana'anta, OUI, da mai ganowa da mai ƙira ya sanya. Aiwatar da masu gano OUI (Ƙungiyoyin Musamman na Musamman). Kungiyar IEEE. A gaskiya ma, tsayinsa zai iya zama ba kawai 3 bytes (24 bits), amma 28 ko 36 ragowa, daga abin da tubalan (MAC Address Block, MA) na adiresoshin nau'i na Large (MA-L), Medium (MA-M) da kuma Ana ƙirƙirar ƙananan (MA-S) bi da bi. Girman block ɗin da aka bayar, a wannan yanayin, zai zama 24, 20, 12 bits ko miliyan 16, miliyan 1, adireshi dubu 4. A halin yanzu akwai kusan bulogi dubu 38 da aka rarraba, ana iya duba su ta amfani da kayan aikin kan layi da yawa, misali ko .
Wanene ya mallaki adiresoshin?
Sauƙaƙan sarrafawa na bayyane IEEE yana ba da cikakkun bayanai masu yawa. Misali, wasu kungiyoyi sun dauki wa kansu tubalan OUI da yawa. Ga jaruman mu:
Mai sayarwa
Yawan tubalan/rikodi
Adadin adireshi, miliyan
Cisco Systems Inc
888
14208
apple
772
12352
Samsung
636
10144
Kudin hannun jari Huawei Technologies Co.,Ltd
606
9696
Intel Corporation
375
5776
ARRIS Group Inc. girma
319
5104
Kamfanin Nokia
241
3856
Private
232
2704
Texas Instruments
212
3392
Kamfanin zte
198
3168
Hukumar Rajista ta IEEE
194
3072
Hewlett Packard
149
2384
Hon Hai Precision
136
2176
TP-LINK
134
2144
Dell Inc.
123
1968
Juniper Networks
110
1760
Sagemcom Broadband SAS
97
1552
Abubuwan da aka bayar na Fiberhome Telecommunication Technologies Co., Ltd. LTD
97
1552
Xiaomi Communications Co., Ltd
88
1408
Guangdong Oppo Mobile Telecommunications Corp. Ltd. girma
82
1312
Google yana da 40 kawai daga cikinsu, kuma wannan ba abin mamaki ba ne: su kansu ba sa samar da na'urorin sadarwa da yawa.
Ba a bayar da tubalan MA kyauta ba, ana iya siyan su akan farashi mai ma'ana (ba tare da kuɗin biyan kuɗi ba) akan $3000, $1800 ko $755, bi da bi. Abin sha'awa, don ƙarin kuɗi (a kowace shekara) kuna iya siyan "boye" bayanan jama'a game da katangar da aka keɓe. Yanzu akwai 232 daga cikinsu, kamar yadda ake iya gani a sama.
Yaushe za mu ƙare da adireshin MAC?
Dukkanmu mun gaji da labaran da ke gudana tsawon shekaru 10 cewa "adireshin IPv4 na gab da ƙarewa." Ee, sabbin tubalan IPv4 ba su da sauƙin samuwa. An san cewa adireshin IP ; Akwai manya-manyan tubalan mallakar manyan kamfanoni da hukumomin gwamnatin Amurka, duk da haka, ba tare da fatan sake rarraba su ga mabukata ba. Yaduwar NAT, CG-NAT da IPv6 ya sanya matsalar karancin adiresoshin jama'a ta ragu sosai.
Adireshin MAC yana da 48 ragowa, wanda 46 za a iya la'akari da "amfani" (me yasa? karantawa), wanda ke ba da adiresoshin 246 ko 1014, wanda shine sau 214 fiye da sararin adireshin IPv4.
A halin yanzu, an rarraba kusan rabin tiriliyan adireshi, ko kuma kawai kashi 0.73% na jimlar adadin. Har yanzu muna da nisa sosai da ƙarewar adireshin MAC.
Ragowar bazuwar
Ana iya ɗauka cewa ana rarraba OUIs ba da gangan ba, kuma mai siyarwa sannan kuma ya ba da adireshi ga na'urorin cibiyar sadarwa ba da gangan ba. Shin haka ne? Bari mu dubi rarraba ragowa a cikin bayanan bayanan adireshin MAC na na'urorin 802.11 a hannuna, waɗanda aka tattara ta tsarin ba da izini na aiki a cikin cibiyoyin sadarwa mara waya. . Adireshin na na'urori ne na gaske waɗanda suka haɗa da Wi-Fi sama da shekaru da yawa a cikin ƙasashe uku. Bugu da kari akwai ƙananan bayanai na na'urorin LAN masu waya 802.3.
Bari mu rushe kowane adireshin MAC (bytes shida) na kowane samfurin zuwa ragowa, byte byte, kuma duba yawan faruwar abin “1” bit a kowane matsayi na 48. Idan an saita bit a cikin cikakken sabani, to yuwuwar samun "1" yakamata ya zama 50%.
Zaɓin Wi-Fi Lamba 1 (RF)
Samfurin Wi-Fi No. 2 (Belarus)
Zaɓin Wi-Fi Lamba 3 (Uzbekistan)
Samfuran LAN (RF)
Adadin bayanai a cikin bayanan
5929000
1274000
366000
1000
Lambar Bit:
% bit "1"
% bit "1"
% bit "1"
% bit "1"
1
48.6%
49.2%
50.7%
28.7%
2
44.8%
49.1%
47.7%
30.7%
3
46.7%
48.3%
46.8%
35.8%
4
48.0%
48.6%
49.8%
37.1%
5
45.7%
46.9%
47.0%
32.3%
6
46.6%
46.7%
47.8%
27.1%
7
0.3%
0.3%
0.2%
0.7%
8
0.0%
0.0%
0.0%
0.0%
9
48.1%
50.6%
49.4%
38.1%
10
49.1%
50.2%
47.4%
42.7%
11
50.8%
50.0%
50.6%
42.9%
12
49.0%
48.4%
48.2%
53.7%
13
47.6%
47.0%
46.3%
48.5%
14
47.5%
47.4%
51.7%
46.8%
15
48.3%
47.5%
48.7%
46.1%
16
50.6%
50.4%
51.2%
45.3%
17
49.4%
50.4%
54.3%
38.2%
18
49.8%
50.5%
51.5%
51.9%
19
51.6%
53.3%
53.9%
42.6%
20
46.6%
46.1%
45.5%
48.4%
21
51.7%
52.9%
47.7%
48.9%
22
49.2%
49.6%
41.6%
49.8%
23
51.2%
50.9%
47.0%
41.9%
24
49.5%
50.2%
50.1%
47.5%
25
47.1%
47.3%
47.7%
44.2%
26
48.6%
48.6%
49.2%
43.9%
27
49.8%
49.0%
49.7%
48.9%
28
49.3%
49.3%
49.7%
55.1%
29
49.5%
49.4%
49.8%
49.8%
30
49.8%
49.8%
49.7%
52.1%
31
49.5%
49.7%
49.6%
46.6%
32
49.4%
49.7%
49.5%
47.5%
33
49.4%
49.8%
49.7%
48.3%
34
49.7%
50.0%
49.6%
44.9%
35
49.9%
50.0%
50.0%
50.6%
36
49.9%
49.9%
49.8%
49.1%
37
49.8%
50.0%
49.9%
51.4%
38
50.0%
50.0%
49.8%
51.8%
39
49.9%
50.0%
49.9%
55.7%
40
50.0%
50.0%
50.0%
49.5%
41
49.9%
50.0%
49.9%
52.2%
42
50.0%
50.0%
50.0%
53.9%
43
50.1%
50.0%
50.3%
56.1%
44
50.1%
50.0%
50.1%
45.8%
45
50.0%
50.0%
50.1%
50.1%
46
50.0%
50.0%
50.1%
49.5%
47
49.2%
49.4%
49.7%
45.2%
48
49.9%
50.1%
50.7%
54.6%
Me yasa irin wannan rashin adalci a cikin 7 da 8 bits? Akwai kusan sifili.
Lallai, ma'auni yana bayyana waɗannan raƙuman ruwa a matsayin na musamman ():
Na takwas (daga farkon) bit na farkon byte na adireshin MAC ana kiransa Unicast/Multicast bit kuma yana ƙayyade nau'in firam (frame) da ake watsawa tare da wannan adireshin, na yau da kullun (0) ko watsawa (1) (multicast ko watsawa). Domin al'ada, sadarwar adaftar cibiyar sadarwa ta unicast, an saita wannan bit zuwa "0" a duk fakitin da aka aika zuwa gare shi.
Abu na bakwai (daga farkon) na farkon byte na adireshin MAC ana kiransa U/L (Universal/Local) bit kuma yana ƙayyade ko adireshin na musamman ne na duniya (0), ko kuma na musamman na gida (1). Ta hanyar tsoho, duk adiresoshin "masu sana'a-dike" na musamman ne na duniya, don haka mafi yawan adiresoshin MAC da aka tattara sun ƙunshi bit na bakwai da aka saita zuwa "0". A cikin teburin abubuwan gano OUI da aka sanya, kusan shigarwar 130 ne kawai ke da ɗan U/L na “1”, kuma a fili waɗannan tubalan adiresoshin MAC ne don buƙatu na musamman.
Daga na shida zuwa na farko na byte na farko, da ragowar bytes na biyu da na uku a cikin abubuwan gano OUI, har ma fiye da haka ana rarraba ragowar da ke cikin bytes 4-6 na adireshin da masana'anta ya ba su daidai ko kaɗan. .
Don haka, a cikin ainihin adireshin MAC na adaftar cibiyar sadarwa, ragowa a zahiri daidai suke kuma ba su da ma'anar fasaha, ban da ɓangarori biyu na sabis na babban byte.
Yaduwa
Abin mamaki wanne masana'antun kayan aikin mara waya ne suka fi shahara? Bari mu haɗa binciken a cikin bayanan OUI tare da bayanai daga samfurin No. 1.
Mai sayarwa
Raba na'urori, %
apple
26,09
Samsung
19,79
Kamfanin Huawei Technologies Co., Ltd. Ltd
7,80
Xiaomi Communications Co., Ltd
6,83
Abubuwan da aka bayar na Sony Mobile Communications Inc
3,29
LG Electronics (Sadarwar Wayar hannu)
2,76
Abubuwan da aka bayar na ASUSTek COMPUTER INC.
2,58
TCT Mobile Ltd. girma
2,13
Kamfanin zte
2,00
ba a samu a cikin IEEE database ba
1,92
Lenovo Mobile Communication Technology Ltd.
1,71
Kamfanin Kamfanin HTC
1,68
Murata Manufacturing
1,31
InPro Comm
1,26
Microsoft Corporation
1,11
Shenzhen TINNO Mobile Technology Corp.
1,02
Motorola (Wuhan) Motsi Technologies Communication Co., Ltd. Ltd.
0,93
Kamfanin Nokia
0,88
Abubuwan da aka bayar na Shanghai Wind Technologies Co., Ltd. Ltd
0,74
Kamfanin Lenovo Mobile Communication (Wuhan) Company Limited ya dogara ne a Jamus
0,71
Aiki ya nuna cewa mafi yawan wadatar adadin masu biyan kuɗi na hanyar sadarwa mara waya a cikin wani wurin da aka bayar, mafi girman rabon na'urorin Apple.
Bambanci
Adireshin MAC na musamman ne? A ka'ida, eh, tunda ana buƙatar kowane mai kera na'ura (MA block owner) don samar da adireshi na musamman ga kowane adaftar hanyar sadarwa da yake samarwa. Duk da haka, wasu masana'antun guntu, wato:
- 00:0A:F5 Airgo Networks, Inc. (yanzu Qualcomm)
- 00:08:22 InPro Comm (yanzu MediaTek)
saita bytes uku na ƙarshe na adireshin MAC zuwa lambar bazuwar, a fili bayan kowace na'ura ta sake yin. Akwai irin waɗannan adireshi dubu 1 a cikin samfurin No. 82 na.
Kuna iya, ba shakka, saita kanku baƙon, adireshin da ba na musamman ba ta hanyar tsara shi da gangan "kamar na maƙwabcinku", gano shi da maharbi, ko zabar shi ba da gangan ba. Hakanan yana yiwuwa a saita kanku adireshin da ba na musamman ba da gangan ta hanyar, misali, maido da madaidaicin na'ura mai ba da hanya tsakanin hanyoyin sadarwa kamar Mikrotik ko OpenWrt.
Menene zai faru idan akwai na'urori guda biyu akan hanyar sadarwa tare da adireshin MAC iri ɗaya? Duk ya dogara da dabaru na kayan aikin cibiyar sadarwa (waya na'ura mai ba da hanya tsakanin hanyoyin sadarwa, mai kula da hanyar sadarwa mara waya). Mafi mahimmanci, duka na'urorin biyu ba za su yi aiki ba ko kuma za su yi aiki na ɗan lokaci. Daga ra'ayi na IEEE matsayin, kariya daga MAC address spoofing an ba da shawarar da za a warware ta amfani da, misali, MACsec ko 802.1X.
Menene idan ka shigar da MAC tare da na bakwai ko na takwas an saita zuwa "1", watau. adireshin gida ko multicast? Mafi mahimmanci, hanyar sadarwar ku ba za ta kula da wannan ba, amma a zahiri irin wannan adireshin ba zai bi ka'idodin ba, kuma yana da kyau kada ku yi hakan.
Yadda bazuwar ke aiki
Mun san cewa don hana bin diddigin motsin mutane ta hanyar dubawa da tattara raƙuman iska, na'urorin MAC na wayar salula sun yi amfani da fasahar bazuwar shekaru da yawa. A bisa ka'ida, lokacin da ake duba raƙuman iska don neman sanannun cibiyoyin sadarwa, wayar hannu ta aika fakiti (rukunin fakiti) na nau'in buƙatun 802.11 tare da adireshin MAC azaman tushen:
Bazuwar da aka kunna tana ba ku damar sakawa ba “dike” ɗaya ba, amma wasu adireshin tushen fakiti, canzawa tare da kowane zagayowar dubawa, kan lokaci, ko ta wata hanya dabam. Yana aiki? Bari mu dubi kididdigar adiresoshin MAC da aka tattara daga iska ta abin da ake kira "Wi-Fi Radar":
Cikakken samfurin
Misali kawai tare da sifili 7th bit
Adadin bayanai a cikin bayanan
3920000
305000
Lambar Bit:
% bit "1"
% bit "1"
1
66.1%
43.3%
2
66.5%
43.4%
3
31.7%
43.8%
4
66.6%
46.4%
5
66.7%
45.7%
6
31.9%
46.4%
7
92.2%
0.0%
8
0.0%
0.0%
9
67.2%
47.5%
10
32.3%
45.6%
11
66.9%
45.3%
12
32.3%
46.8%
13
32.6%
50.1%
14
33.0%
56.1%
15
32.5%
45.0%
16
67.2%
48.3%
17
33.2%
56.9%
18
33.3%
56.8%
19
33.3%
56.3%
20
66.8%
43.2%
21
67.0%
46.4%
22
32.6%
50.1%
23
32.9%
51.2%
24
67.6%
52.2%
25
49.8%
47.8%
26
50.0%
50.0%
27
50.0%
50.2%
28
50.0%
49.8%
29
50.0%
49.4%
30
50.0%
50.0%
31
50.0%
49.7%
32
50.0%
49.9%
33
50.0%
49.7%
34
50.0%
49.6%
35
50.0%
50.1%
36
50.0%
49.5%
37
50.0%
49.9%
38
50.0%
49.8%
39
50.0%
49.9%
40
50.0%
50.1%
41
50.0%
50.2%
42
50.0%
50.2%
43
50.0%
50.1%
44
50.0%
50.1%
45
50.0%
50.0%
46
50.0%
49.8%
47
50.0%
49.8%
48
50.1%
50.9%
Hoton ya bambanta.
Abu na 8 na byte na farko na adireshin MAC har yanzu yana daidai da yanayin Unicast na adireshin SRC a cikin fakitin neman bincike.
An saita na 7th bit zuwa Local a cikin 92.2% na lokuta, i.e. Tare da ingantaccen matakin ƙarfin gwiwa, zamu iya ɗauka cewa ainihin yawancin adiresoshin da aka tattara an bazu su, kuma ƙasa da 8% na gaske ne. A wannan yanayin, rarraba ragowa a cikin OUI don irin waɗannan adireshi na gaske kusan yayi daidai da bayanan da ke cikin tebur da ya gabata.
Wanne masana'anta, bisa ga OUI, ya mallaki adiresoshin da aka bazu (watau tare da 7th bit a cikin "1")?
Mai ƙira ta OUI
Raba tsakanin duk adireshi
ba a samu a cikin IEEE database ba
62.45%
Google Inc.
37.54%
hutawa
0.01%
Haka kuma, duk adiresoshin da aka ba wa Google suna na OUI iri ɗaya ne tare da prefix DA:A1:19. Menene wannan prefix? Mu duba ciki .
private static final MacAddress BASE_GOOGLE_MAC = MacAddress.fromString("da:a1:19:0:0:0");Stock Android yana amfani da OUI na musamman, mai rijista lokacin neman hanyoyin sadarwa mara waya, ɗaya daga cikin kaɗan masu saiti na bakwai.
Yi lissafin ainihin MAC daga bazuwar ɗaya
Mu gani a can:
private static final long VALID_LONG_MASK = (1L << 48) - 1;
private static final long LOCALLY_ASSIGNED_MASK = MacAddress.fromString("2:0:0:0:0:0").mAddr;
private static final long MULTICAST_MASK = MacAddress.fromString("1:0:0:0:0:0").mAddr;
public static @NonNull MacAddress createRandomUnicastAddress(MacAddress base, Random r) {
long addr;
if (base == null) {
addr = r.nextLong() & VALID_LONG_MASK;
} else {
addr = (base.mAddr & OUI_MASK) | (NIC_MASK & r.nextLong());
}
addr |= LOCALLY_ASSIGNED_MASK;
addr &= ~MULTICAST_MASK;
MacAddress mac = new MacAddress(addr);
if (mac.equals(DEFAULT_MAC_ADDRESS)) {
return createRandomUnicastAddress(base, r);
}
return mac;
}
Duk adireshin, ko ƙananan bytes uku, tsarkakakku ne Random.na gabaLong(). "Fara dawo da ainihin MAC" zamba ne. Tare da babban ƙarfin gwiwa, za mu iya tsammanin masana'antun wayar Android suna amfani da wasu, OUI marasa rajista. Ba mu da lambar tushe ta iOS, amma galibi ana amfani da irin wannan algorithm a can.
Abin da ke sama baya soke aikin wasu hanyoyin don cire sunan masu biyan kuɗin Wi-Fi, dangane da nazarin wasu fagage na firam ɗin neman bincike, ko alaƙar mitar buƙatun da na'urar ta aika. Koyaya, dogaron bin mai biyan kuɗi ta amfani da hanyoyin waje yana da matuƙar matsala. Bayanan da aka tattara za su fi dacewa don nazarin matsakaicin matsakaici / matsakaicin nauyi ta wuri da lokaci, bisa lambobi masu yawa, ba tare da yin la'akari da takamaiman na'urori da mutane ba. Wadanda “ciki” ne kawai, masu kera OS ta wayar hannu da kansu, da aikace-aikacen da aka shigar suna da cikakkun bayanai.
Menene zai iya zama haɗari game da wani ya san adireshin MAC na na'urar ku? Ana iya ƙaddamar da hana harin sabis don cibiyoyin sadarwar waya da mara waya. Don na'urar mara waya, haka ma, tare da wasu yuwuwar yana yiwuwa a yi rikodin lokacin bayyanarsa a wurin da aka shigar da firikwensin. Ta hanyar zazzage adireshin, zaku iya ƙoƙarin "kamar" a matsayin na'urar ku, wanda zai iya aiki kawai idan ba a yi amfani da ƙarin matakan tsaro ba (izni da/ko ɓoyewa). 99.9% na mutane a nan ba su da wani abin damuwa.
Adireshin MAC ya fi rikitarwa fiye da alama, amma ya fi sauƙi fiye da yadda zai iya zama.
source: www.habr.com