Adilesi ya Media Access Control (MAC) ndi nambala yophatikizapo yogwiritsidwa ntchito podziŵika bwino makasitomala apakompyuta . Ziwerengero zimenezi (zomwe nthawi zina zimatchedwa "hardware adresse" kapena "maadiresi enieni") zimalowetsedwa mu intaneti hardware panthawi yogulitsa, kapena kusungidwa ku firmware, ndipo silingasinthidwe.
Ena amawatcha iwo "ma Adresse Ethernet" chifukwa cha mbiri yakale, koma mitundu yambiri ya mautumiki onse amagwiritsa ntchito mauthenga a MAC kuphatikizapo Ethernet , Wi-Fi , ndi Bluetooth .
Mafomu a Makhalidwe a MAC
Maadiresi amtundu wamakono ali nambala 12 (6 bytes kapena 48 bits ) nambala za hexadecimal . Mwa msonkhano, nthawi zambiri amalembedwa chimodzi mwa zigawo zitatu zotsatirazi:
- MM: MM: MM: SS: SS: SS
- MM-MM-MM-SS-SS-SS
- MMM.MMM.SSS.SSS
Manambala 6 otsala (24 bits) otchedwa "choyambirira" akugwirizanitsidwa ndi wopanga adapter. Wogulitsa aliyense amalembetsa ndipo amapeza malemba a MAC monga operekedwa ndi IEEE. Ogulitsa nthawi zambiri amakhala ndi chiwerengero chambiri chiwerengero chokhudzana ndi zinthu zawo zosiyana. Mwachitsanzo, prefixes 00:13:10, 00: 25: 9C ndi 68: 7F: 74 (kuphatikizapo ena ambiri) onse ndi a Linksys ( Cisco Systems ).
Mawerengero oyenera a adondomeko ya MAC amaimira nambala yodziwika kwa chipangizo chokha. Pakati pa zipangizo zonse zopangidwa ndi chiwerengero chimodzimodzi cha wogulitsa, aliyense ali ndi nambala yake yapadera ya 24-bit. Onani kuti hardware yochokera kwa ogulitsa osiyanasiyana ikhoza kuchitika kuti agawane gawo limodzi la chipangizo cha aderi.
Ma Adilesi a MAC 64-bit
Ngakhale ma adatimenti a MAC ali ndi mautali 48, kutalika kwa mitundu yosiyanasiyana kumafuna ma adresse 64-bit. ZigBee opanda pakhomo pawokha ndi ma intaneti ena ofanana ndi a IEEE 802.15.4, mwachitsanzo, amafuna ma adatha a 64-bit MAC akonzekere pa zipangizo zawo za hardware.
Mapulogalamu a TCP / IP omwe amagwiritsidwa ntchito pa IPv6 akugwiritsanso ntchito njira zosiyana polankhulana ndi ma adilesi a MAC poyerekeza ndi IPv4 . M'malo mwa maadiresi a 64-bit, IPv6 amamasulira molumikiza 48-bit MAC adiresi ya 64-bit powonjezeramo mwa kuika chiwerengero cha (bitcoded) 16-bit mtengo FFFE pakati pa chigulitsi cha wogulitsa ndi chidziwitso cha chipangizo. IPv6 imatchula manambalawa "zizindikiro" kuti aziwasiyanitsa ndi adalondola a adresi 64-bit.
Mwachitsanzo, ma intaneti 48-bit MAC 00: 25: 96: 12: 34: 56 amawoneka pa intaneti ya IPv6 monga (yolembedwa kale mwa mitundu iwiriyi):
- 00: 25: 96: FF: FE: 12: 34: 56
- 0025: 96FF: FE12: 3456
MAC vs. Mauthenga a IP Address
Mapulogalamu a TCP / IP amagwiritsa ntchito maadiresi a MAC ndi ma Adresse a IP koma chifukwa chosiyana. Maadiresi a MAC amakhalabe osakayika pa hardware ya chipangizo pomwe adesi ya IP ya chipangizo chomwecho ingasinthidwe malingana ndi kasinthidwe ka makina a TCP / IP. Media Access Control ikugwira ntchito pa Gawo 2 lachitsanzo cha OSI pamene Internet Protocol ikugwira ntchito pa Gawo 3 . Izi zimalola MAC kuyanjanitsa kuthandizira machitidwe ena kupatula TCP / IP.
Mapulogalamu a IP amayendetsa kutembenuka pakati pa IP ndi MAC maadiresi pogwiritsa ntchito Address Resolution Protocol (ARP) . Dynamic Host Configuration Protocol (DHCP) imadalira ARP kuyang'anira ntchito yapadera ya ma Adresse a IP ku zipangizo.
Makhalidwe a MAC A Cloning
Ena Omwe Amatumikira pa Intaneti amagwirizanitsa aliyense wa makaunti awo ogula makasitomala kumakalata a MAC a home network router (kapena chipangizo china cha chipata). Adilesi yowonetsedwa ndi wothandizirayo isintha mpaka kasitomala asintha njira yawo, monga kukhazikitsa router yatsopano . Pamene chipata chokhalamo chimasinthidwa, Internet Provider tsopano akuwona MAC yodalirika ikufotokozedwa ndipo imatseka ma network kuti asayambe pa intaneti.
Ndondomeko yotchedwa "cloning" imathetsa vutoli pothandizira routa (chipata) kuti adziŵe maadiresi akale a MAC kwa wothandizira ngakhale adresse yake ya hardware ndi yosiyana. Olamulira akhoza kukonza router yawo (poganiza kuti imathandizira mbaliyi, monga ambiri amachitira) kugwiritsa ntchito njira yothandizila ndi kulowa m'dilesi ya MAC ya chipata chakale kupita muzokonza. Pamene cloning sichipezeka, kasitomala afunsane ndi wothandizira ntchito kuti alembetse chipangizo chawo chatsopano m'malo mwake.