Onye ọ bụla maara na ndị bytes isii a, na-egosipụtakarị na hexadecimal format, na-ekenye na kaadị netwọk na ụlọ ọrụ mmepụta ihe, na-eyikwa ka enweghị usoro. Ụfọdụ ndị maara na bytes atọ mbụ nke adreesị ahụ bụ ID onye nrụpụta, ma e kenyere ha bytes atọ fọdụrụnụ. A makwaara na ị nwere ike ịtọ onwe gị aka ike adreesị. Ọtụtụ ndị mmadụ anụla maka "adreesị enweghị usoro" na Wi-Fi.
Ka anyị chọpụta ihe ọ bụ.
Adreesị MAC (adreesị njikwa mgbasa ozi) bụ ihe nchọpụta pụrụ iche ekenyere ihe nkwụnye netwọkụ, ejiri ya na netwọkụ ụkpụrụ IEEE 802, ọkachasị Ethernet, Wi-Fi na Bluetooth. Na eze, a na-akpọ ya "ihe nchọpụta ụdị EUI-48". Site na aha ahụ, o doro anya na adreesị ahụ dị 48 bit ogologo, ya bụ. 6 bytes. Enweghị ọkọlọtọ anabatara maka ide adreesị (ma megidere adreesị IPv4, ebe ntụpọ na-ekewa octets mgbe niile) A na-edekarị ya dị ka ọnụọgụ hexadecimal isii kewapụrụ site na colon: 00:AB:CD:EF:11: 22, ọ bụ ezie na ụfọdụ ndị na-emepụta ngwá ọrụ na-ahọrọ akara 00 -AB-CD-EF-11-22 na ọbụna 00ab.cdef.1122.
N'akụkọ ihe mere eme, a na-agbanye adreesị na ROM nke chipset kaadị netwọk na-enweghị ike gbanwee ha na-enweghị onye na-eme ihe ọkụ, ma n'oge a enwere ike ịgbanwe adreesị ahụ na mmemme site na sistemụ arụmọrụ. Ị nwere ike iji aka gị dozie adreesị MAC nke kaadị netwọk na Linux na MacOS (mgbe niile), Windows (ihe fọrọ nke nta ka ọ bụrụ mgbe niile, ọ bụrụ na onye ọkwọ ụgbọala na-enye ohere), Android (naanị gbanyere mkpọrọgwụ); Na iOS (na-enweghị mgbọrọgwụ) aghụghọ dị otú ahụ agaghị ekwe omume.
Ọdịdị adreesị
Adreesị ahụ nwere akụkụ nke njirimara onye nrụpụta, OUI, yana ihe njirimara nke onye nrụpụta kenyere. Ọrụ nke ihe nchọpụta OUI (Nhazi Pụrụ Identifier). Nzukọ IEEE. N'ezie, ogologo ya nwere ike ọ bụghị naanị 3 bytes (24 ibe n'ibe), ma 28 ma ọ bụ 36 ibe n'ibe, nke blocks (MAC Address Block, MA) nke adreesị nke ụdị Large (MA-L), Ọkara (MA-M) na A na-etolite obere (MA-S) n'otu n'otu. Ogo nke ngọngọ nyere, na nke a, ga-abụ 24, 20, 12 bits ma ọ bụ 16 nde, 1 nde, 4 puku adreesị. Enwere ihe dị ka puku blocks 38 ugbu a na-ekesa, enwere ike ịlele ha site na iji ọtụtụ ngwaọrụ ịntanetị, dịka ọmụmaatụ ma ọ bụ .
Onye nwe adreesị?
Nhazi dị mfe nke ọha dị IEEE na-enye ọtụtụ ozi. Dịka ọmụmaatụ, ụfọdụ ụlọ ọrụ ewerela onwe ha ọtụtụ ihe mgbochi OUI. Nke a bụ ndị dike anyị:
Onye na-ere ahịa
Ọnụọgụ nke ngọngọ/ndekọ
Ọnụọgụ nke adreesị, nde
Cisco Systems Inc
888
14208
Apple
772
12352
Samsung
636
10144
Ụgwọ nke ụlọ ọrụ Huawei Technologies Co., Ltd
606
9696
Intel Corporation
375
5776
Ụlọ ọrụ ARRIS GROUP INC.
319
5104
Nokialọ ọrụ Nokia
241
3856
Private
232
2704
Texas Instruments
212
3392
Ụlọ ọrụ zte
198
3168
Ndị ikike ndebanye aha IEEE
194
3072
Hewlett mkpọard
149
2384
Hon Hai nkenke
136
2176
TP-njikọ
134
2144
Dell Inc.
123
1968
Netiper Networks
110
1760
Ụgwọ nke ụlọ ọrụ Sagemcom Broadband SAS
97
1552
Ụlọ ọrụ Fiberhome Telecommunication Technologies Co., Ltd. LTD
97
1552
Ụgwọ nke ụlọ ọrụ Xiaomi Communications Co., Ltd
88
1408
Ụgwọ nke ụlọ ọrụ Guangdong Oppo Mobile Telecommunications Corp. Ltd
82
1312
Google nwere naanị 40 n'ime ha, nke a abụghịkwa ihe ijuanya: ha onwe ha anaghị emepụta ọtụtụ ngwaọrụ netwọk.
Anaghị enye blocks MA n'efu, enwere ike zụta ha maka ọnụ ahịa ezi uche dị na ya (na-enweghị ego ndenye aha) maka $3000, $1800 ma ọ bụ $755, n'otu n'otu. N'ụzọ na-akpali mmasị, maka ego ọzọ (kwa afọ) ị nwere ike ịzụta "zobe" ozi ọha na eze gbasara ngọngọ ekenyela. E nwere ugbu a 232 n'ime ha, dị ka a pụrụ ịhụ n'elu.
Kedu mgbe adreesị MAC ga-agwụ?
Akụkọ ndị na-eme kemgbe afọ 10 na "adreesị IPv4 na-achọ ịgwụ." Anyị niile agwụla anyị. Ee, ngọngọ IPv4 ọhụrụ adịkwaghị mfe inweta. A maara na adreesị IP ; Enwere nnukwu ụlọ ọrụ buru ibu na ụlọ ọrụ gọọmentị US nwere, n'agbanyeghị, na-enwe obere olile anya ikesa ha nye ndị nọ na mkpa. Mmụba nke NAT, CG-NAT na IPv6 emeela ka nsogbu nke ụkọ adreesị ọha na-adịchaghị njọ.
Adreesị MAC nwere 48 ibe n'ibe, nke 46 nwere ike na-atụle "bara uru" ( gịnị mere? na-agụ na), nke na-enye 246 ma ọ bụ 1014 adreesị, nke bụ 214 ugboro karịa IPv4 adreesị ohere.
Ugbu a, e kesaala ihe dị ka ọkara puku ijeri adreesị, ma ọ bụ naanị 0.73% nke mkpokọta olu. Anyị ka dị nnọọ anya site na ịpụ na adreesị MAC.
Iberibe enweghị usoro
Enwere ike iche na a na-ekesa OUI n'enweghị usoro, onye na-ere ahịa na-ekenye adreesị na ngwaọrụ netwọk n'otu n'otu. Ọ dị otú ahụ? Ka anyị leba anya na nkesa nke ibe n'ime ọdụ data nke adreesị MAC nke ngwaọrụ 802.11 dị n'aka m, anakọtara site na sistemụ ikike ọrụ na netwọk ikuku. . Adreesị ndị a bụ nke ezigbo ngwaọrụ ejikọrọ na Wi-Fi ọtụtụ afọ na mba atọ. Na mgbakwunye, enwere obere nchekwa data nke ngwaọrụ LAN 802.3 wired.
Ka anyị kwatuo adreesị MAC nke ọ bụla (bites isii) nke ọ bụla n'ime ihe atụ ahụ n'ime ibe n'ibe, byte site byte, wee lelee ugboro ole nke “1” bit na nke ọ bụla n'ime 48 ọnọdụ. Ọ bụrụ na edobere bit ahụ n'ụzọ zuru oke, mgbe ahụ ohere nke ịnweta "1" kwesịrị ịbụ 50%.
Nhọrọ Wi-Fi No. 1 (RF)
Ihe nlele Wi-Fi No. 2 (Belarus)
Nhọrọ Wi-Fi No. 3 (Uzbekistan)
Nlele LAN (RF)
Ọnụọgụ ndekọ dị na nchekwa data
5929000
1274000
366000
1000
Nọmba ọnụọgụ:
% 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%
Kedu ihe kpatara mmegbu dị otú ahụ na 7 na 8 bits? Ọ fọrọ nke nta ka ọ bụrụ efu mgbe niile.
N'ezie, ọkọlọtọ na-akọwapụta ibe n'ibe ndị a dị ka ndị pụrụ iche ():
Nke asatọ (site na mmalite) bit nke mbụ byte nke adreesị MAC ka a na-akpọ Unicast/Multicast bit na-ekpebi ụdị etiti (frame) na-ebufe na adreesị a, mgbe (0) ma ọ bụ mgbasa ozi (1) (multicast or mgbasa ozi). Maka nzikọrịta ihe nkwụnye netwọkụ unicast nkịtị, atọrọ ntakịrị a ka ọ bụrụ “0” na ngwugwu niile ezigara ya.
Nke asaa (site na mmalite) bit nke mbụ byte nke adreesị MAC ka a na-akpọ U/L (Universal/Local) bit ma na-ekpebi ma adreesị ahụ ọ bụ ihe pụrụ iche zuru ụwa ọnụ (0), ma ọ bụ na mpaghara pụrụ iche (1). Site na ndabara, adreesị “onye nrụpụta-stitched” niile bụ ihe pụrụ iche zuru ụwa ọnụ, yabụ ihe ka ọtụtụ n'ime adreesị MAC anakọtara nwere ntakịrị nke asaa ka edobere “0”. Na tebụl nke ihe nchọpụta OUI ekenyere, naanị ihe dị ka ndenye 130 nwere ntakịrị U/L nke “1”, ma o doro anya na ndị a bụ ngọngọ nke adreesị MAC maka mkpa pụrụ iche.
Site na nke isii ruo nke mbụ nke byte nke mbụ, a na-ekesa nkebi nke abụọ na nke atọ n'ime ihe nchọpụta OUI, na ọbụna karị, a na-ekesa ihe dị na 4-6 bytes nke adreesị nke onye nrụpụta nyere ya ma ọ bụ karịa. .
Ya mere, na adreesị MAC n'ezie nke nkwụnye netwọk, ibe n'ezie bụ nhata na enweghị ihe ọ pụtara nkà na ụzụ, ma e wezụga nkebi ọrụ abụọ nke nnukwu byte.
Ọdịnihu
Na-eche ndị na-emepụta akụrụngwa ikuku kacha ewu ewu? Ka anyị jikọta ọchụchọ dị na nchekwa data OUI na data sitere na sample No. 1.
Onye na-ere ahịa
Oke nke ngwaọrụ,%
Apple
26,09
Samsung
19,79
Ụlọ ọrụ Huawei Technologies Co., Ltd. Ltd
7,80
Ụgwọ nke ụlọ ọrụ Xiaomi Communications Co., Ltd
6,83
Akụkọ ihe mere eme nke Sony Mobile Communications Inc
3,29
LG Electronics (Nkwukọrịta ekwentị)
2,76
Ụlọ ọrụ ASUSTek COMPUTER INC.
2,58
Ụlọ ọrụ TCT Mobile Ltd
2,13
Ụlọ ọrụ zte
2,00
ahụghị na IEEE nchekwa data
1,92
Ụgwọ nke ụlọ ọrụ Lenovo Mobile Communication Technology Ltd.
1,71
Corporationlọ ọrụ HTC
1,68
Murata Manufacturing
1,31
InPro Comm
1,26
Microsoft Corporation
1,11
Ụlọ ọrụ Shenzhen TINNO Mobile Technology Corp.
1,02
Ụgwọ nke ụlọ ọrụ Motorola (Wuhan) Mobility Technologies Communication Co., Ltd. Ltd.
0,93
Nokialọ ọrụ Nokia
0,88
Ụlọ ọrụ Shanghai Wind Technologies Co., Ltd. Ltd
0,74
Ụlọ ọrụ Lenovo Mobile Communication (Wuhan) Company Limited
0,71
Omume na-egosi na ka ọnụ ọgụgụ ndị debanyere aha netwọk ikuku na-enwe ọganihu n'otu ebe, na-abawanye òkè nke ngwaọrụ Apple.
Ịdị n'otu
Adreesị MAC pụrụ iche? Na tiori, ee, ebe ọ bụ na onye nrụpụta ngwaọrụ ọ bụla (MA block nwe) chọrọ inye adreesị pụrụ iche maka ihe nkwụnye netwọkụ ọ bụla ọ na-emepụta. Agbanyeghị, ụfọdụ ndị na-emepụta mgbawa, ya bụ:
- 00:0A:F5 Airgo Networks, Inc. (ugbu a Qualcomm)
- 00:08:22 InPro Comm (ugbu a MediaTek)
tọọ bytes atọ ikpeazụ nke adreesị MAC ka ọ bụrụ nọmba enweghị usoro, o doro anya na mgbe ngwaọrụ ọ bụla malitegharịrị. Enwere puku adres ndị dị otú ahụ dị puku iri asatọ na abụọ n'ihe atụ nke 1 nke m.
Ị nwere ike, n'ezie, ịtọ onwe gị adreesị mba ọzọ, nke na-abụghị nke pụrụ iche site n'iji nlezianya dozie ya "dị ka nke onye agbata obi gị", na-achọpụta ya na onye na-amị amị, ma ọ bụ họrọ ya na enweghị usoro. Ọ ga-ekwe omume na mberede ịtọ onwe gị adreesị na-abụghị nke pụrụ iche site, dịka ọmụmaatụ, iweghachi nhazi ndabere nke rawụta dị ka Mikrotik ma ọ bụ OpenWrt.
Kedu ihe ga - eme ma ọ bụrụ na enwere ngwaọrụ abụọ na netwọkụ nwere otu adreesị MAC? Ihe niile dabere na mgbagha nke akụrụngwa netwọkụ (wired router, wireless network control). O yikarịrị, ngwaọrụ abụọ ahụ agaghị arụ ọrụ ma ọ bụ na-arụ ọrụ n'otu oge. Site n'echiche nke ụkpụrụ IEEE, a na-atụ aro ka a dozie nchebe megide spoofing adreesị MAC site na iji, dịka ọmụmaatụ, MACsec ma ọ bụ 802.1X.
Gịnị ma ọ bụrụ na ị wụnye MAC na nke asaa ma ọ bụ nke asatọ bit ka "1", i.e. adreesị mpaghara ma ọ bụ multicast? O yikarịrị, netwọkụ gị agaghị aṅa ntị na nke a, mana na adreesị dị otú ahụ agaghị agbaso ụkpụrụ ahụ, ọ ka mma ka ị ghara ime ya.
Kedu ka randomization si arụ ọrụ
Anyị maara na iji gbochie nsuso mmegharị ndị mmadụ site na nyocha na ịnakọta ikuku, sistemụ arụmọrụ smartphone MAC ejirila teknụzụ randomization kemgbe ọtụtụ afọ. N'ụzọ doro anya, mgbe ị na-enyocha ikuku ikuku na-achọ netwọkụ ndị ama ama, ama na-eziga ngwugwu (otu ngwugwu) nke ụdị arịrịọ 802.11 na adreesị MAC dị ka isi mmalite:
Agbanyere randomization na-enye gị ohere ịkọwapụta ọ bụghị “ndụgide” nke, kama ụfọdụ adreesị isi iyi ndị ọzọ ngwugwu, na-agbanwe na nke ọ bụla nyocha okirikiri, ka oge na-aga, ma ọ bụ n'ụzọ ọzọ. Ọ na-arụ ọrụ? Ka anyị lelee ọnụ ọgụgụ nke adreesị MAC nke ihe a na-akpọ "Wi-Fi Radar" anakọtara site na ikuku:
Nlereanya dum
Sample naanị na efu 7th bit
Ọnụọgụ ndekọ dị na nchekwa data
3920000
305000
Nọmba ọnụọgụ:
% 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%
Foto a dị nnọọ iche.
Nkeji 8 nke bat nke mbụ nke adreesị MAC ka dabara na ụdị Unicast nke adreesị SRC na ngwugwu arịrịọ nyocha.
Edobere ntakịrị nke asaa ka ọ bụrụ Mpaghara na 7% nke ikpe, ya bụ. Site n'inwe obi ike ziri ezi, anyị nwere ike iche na kpọmkwem ọtụtụ n'ime adreesị anakọtara bụ nke a na-ahazi, na ihe na-erughị 92.2% dị adị. N'okwu a, nkesa nke ibe n'ibe na OUI maka ezigbo adreesị dị otú ahụ dabara na data dị na tebụl gara aga.
Kedu onye nrụpụta, dị ka OUI si kwuo, nwere adreesị ndị a na-enweghị usoro (ya bụ na nke 7th na "1")?
Onye nrụpụta sitere na OUI
Kekọrịta n'etiti adreesị niile
ahụghị na IEEE nchekwa data
62.45%
Google Inc.
37.54%
zuru ike
0.01%
Ọzọkwa, adreesị niile edobere na Google bụ nke otu OUI nwere prefix DA:A1:19. Gịnị bụ prefix a? Ka anyị leba anya n'ime .
private static final MacAddress BASE_GOOGLE_MAC = MacAddress.fromString("da:a1:19:0:0:0");Android Stock na-eji OUI pụrụ iche, edebanyere aha mgbe ị na-achọ netwọk ikuku, otu n'ime ole na ole nwere ntọala nke asaa.
Gbakọọ ezigbo MAC site na enweghị usoro
Ka anyị hụ ebe ahụ:
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;
}
Adreesị ahụ dum, ma ọ bụ bytes atọ dị ala, dị ọcha Random.nextLong(). "Nweghachi nke ezigbo MAC" bụ ojoro. Site n'inwe ntụkwasị obi dị elu, anyị nwere ike ịtụ anya na ndị na-emepụta ekwentị gam akporo na-eji OUI ndị ọzọ edebanyeghị aha. Anyị enweghị koodu isi iyi iOS, mana o yikarịrị ka a na-eji algọridim yiri ya ebe ahụ.
Nke a dị n'elu anaghị akagbuo ọrụ nke usoro ndị ọzọ maka ịmechapụ ndị debanyere aha Wi-Fi aha, dabere na nyocha nke mpaghara ndị ọzọ nke etiti arịrịọ nyocha, ma ọ bụ njikọ nke ugboro arịrịọ ngwaọrụ ahụ zitere. Agbanyeghị, iji ụzọ mpụga nsonye onye debanyere aha ya bụ nnukwu nsogbu. Ihe data anakọtara ga-adaba adaba maka nyochaa nkezi / kacha elu site na ọnọdụ na oge, dabere na ọnụ ọgụgụ buru ibu, na-ekwughị maka ngwaọrụ na ndị mmadụ. Naanị ndị "n'ime", ndị na-emepụta OS mkpanaka n'onwe ha, na ngwa arụnyere nwere data ziri ezi.
Kedu ihe nwere ike ịdị ize ndụ maka onye ọzọ ịmara adreesị MAC nke ngwaọrụ gị? Enwere ike ịmalite ịgọnarị mwakpo ọrụ maka netwọk ikuku na ikuku. Maka ngwaọrụ ikuku, Ọzọkwa, na ụfọdụ ihe gbasara nke puru omume ọ ga-ekwe omume ịdekọ oge ọdịdị ya na ebe etinyere ihe mmetụta. Site n'ịkwado adreesị ahụ, ị nwere ike ịnwa ime ka ọ bụrụ ngwaọrụ gị, nke nwere ike ịrụ ọrụ ma ọ bụrụ na ejighị usoro nchebe ọzọ (ikike na / ma ọ bụ izo ya ezo). 99.9% ndị mmadụ ebe a enweghị ihe na-echegbu onwe ha.
Adreesị MAC dị mgbagwoju anya karịa ka ọ dị, mana ọ dị mfe karịa ka ọ nwere ike ịdị.
isi: www.habr.com