NAT - he aha te mea tenei? Tatūnga NAT

Translation Wāhitau Whatunga (NAT) ko te tikanga o te whakaraupapa anō kotahi wāhi wāhitau ki tetahi e te huri i te mōhiohio wāhitau whatunga i roto i te IP (Kawa Ipurangi). E ko, e puta ke te pane pākete i te wa, ina ko ratou i roto i tauwhiro i roto i te pūrere ararere. I whakamahia tuatahi tenei tikanga ki te anga tapatahi waka i roto i IP-whatunga, ia ope kahore Tataunga Anō. riro ia te taputapu rongonui, me te nui hoki te tiaki me te tohatoha o te wāhi wāhitau ao i roto i te tikanga o te kaimahi o wāhitau IPv4.

NAT - he aha te mea tenei?

Ko te whakamahi taketake o te translation wāhitau whatunga ko ki te mahere i ia wāhitau i wāhi wāhitau tetahi ki te wāhitau hāngai i roto i te tahi atu wāhi. Hei tauira, he mea e tika ana ki te kua ke te kaiwhakarato ratonga Ipurangi, a kore e taea ki te kauwhau nuitia te ara hou ki te whatunga te kaiwhakamahi. I raro i nga tikanga kei te piki whakamahia kēkeno ao IP-wāhitau hangarau NAT wāhi raurangi mai i te mutunga o nga 1990 i roto i te taha ki te IP-whakamunatanga (i te mea te tikanga o te waka e rave rahi IP-wāhitau i te wāhi kotahi). whakatinana ana tēnei tikanga i roto i te pūrere ararere e whakamahi tepu translation stateful ki te whakaatu "huna" wāhitau ki tetahi IP-wāhitau, me whakamua te puta IP-pākete ki te putanga. Ko te kupu, e whakaaturia mai ana e ratou i roto i o te pūrere ararere. I roto i whakamuri kōrero hongere e whakaaturia urupare i roto i te puna IP-wāhitau whakamahi i te ture rongoa i roto i nga tepu translation. tepu translation Ture, i roto i te tahuri, whakawāteatia i muri i te wā poto ki te kore e te waka hou whakahōu i tona mana. Ko te tikanga taketake o NAT tenei. te e te tikanga o te reira?

Mā tēnei aratuka ki a koe te kōrero i roto i te pouara anake ina e hanga he hononga ki te whatunga whakamunatia, rite hanga reira he tepu translation. Hei tauira, he pūtirotiro tukutuku i roto i te whatunga taea te tirotiro i te pae ki waho, engari, ki te kahore tāuta waho, e kore e taea te whakatuwhera i te reira i te rauemi, tūnga ki reira. Otiia, tukua te nuinga o ngā pūrere NAT tenei ra te kaiwhakahaere whatunga ki te whirihora i te tāurunga translation tepu mō te whakamahi pūmau. Kei te maha tenei āhuatanga tuku ki rite pateko NAT tauranga ranei whakamua, a taea ana e ia hokohoko e ahu i roto i te "waho" whatunga ki tae te ope ūnga i roto i te whatunga whakamunatia.

Nā whakamahia ki te te rongonui o tenei tikanga ki te tiaki i te wāhi wāhitau IPv4, te wā NAT (ko te mea ko te mau tenei - i runga), kua riro te reira tata fenāpasi ki te tikanga whakamunatanga.

No te mea ketia NAT te mōhiohio wāhitau o te IP-pākete, kua reira pānga nui mo te kounga o te hononga ipurangi, me te titau aro tata ki te taipitopito o tona whakatinanatanga.

Methods o Mā te NAT rerekē i ia atu i roto i to ratou whanonga ngā i roto i ngā take rerekē e whai wāhi mai pānga i runga i te waka whatunga.

Basic NAT

Ko te momo māmā o Wāhitau Translation Whatunga (NAT) whakarato haapurorohia te IP-wāhitau o "kotahi-ki-tetahi." RFC 2663 Ko te momo matua o te haapurororaa. I roto i tenei momo o te huringa anake te IP-wāhitau, me te Checksum IP-pane. Ka taea te whakamahi i te momo matua o te translation ki te hono i te rua IP-whatunga e e hotokore whakatutuki.

NAT - Kei te e honotanga "kotahi-ki-he tokomaha"?

Te nuinga momo o NAT taea mahere mano tūmataiti maha ki te whakaritea nuitia IP-wāhitau kotahi. I roto i te whirihoranga angamaheni, whakamahi he whatunga rohe tetahi o nga wāhitau IP-whatu "tūmataiti" whakaritea (RFC 1918). Ko te pouara i runga i taua whatunga he wāhitau tūmataiti i roto i tenei wāhi.

hono hoki te pouara ki te Internet mā te whakamahi i te "tūmatanui" wāhitau whakaritea e koutou ISP. Ka rite ki waka haere i te whatunga rohe ki te wāhitau Ipurangi o te puna o ia pākete e iritihia i runga i te ngaro i te wāhitau tūmataiti ki te iwi whānui. Ko te pouara aroturuki raraunga taketake e pā ana ki ia hononga hohe (ngā te wāhitau ūnga me tauranga). No te haere mai te whakautu hoki ki a ia, whakamahia e ia te raraunga hononga rongoa e te i roto i te wā arawaho ki te whakatau i te wāhitau tūmataiti o te whatunga ā-ki nei ki te unga i te whakautu.

Ko tētahi painga o tenei taumahinga ko e te kaimahi te reira rite te otinga mahi ki te rohirohi haamouraa o te wāhi wāhitau IPv4. Ka taea te hono Ahakoa whatunga nui ki te Ipurangi i roto i te kotahi IP-wāhitau.

pākete datagram katoa ki whatunga IP-e hāngai ana i 2 IP-wāhitau - te pūtake me te ūnga. Tikanga, pākete haere i te whatunga tūmataiti ki te whatunga tūmatanui, ka whai i te wāhitau pūtake o pākete, te huri i roto i te whakawhitinga i te whatunga tūmatanui ki te hoki tūmataiti. He taea hoki atu whirihoranga matatini.

āhuatanga

kia whai tahi mau āhuatanga motuhake NAT mahi. Ki te karo i te mau fifi, ko e founga ki te iriti i te mōkī hoki rapu ratou atu akatuke'anga. Ko te nuinga o te waka Ipurangi nui haere i roto i te TCP kawa me UDP, a kua puta ke tau tauranga kia tīmata te huinga o IP-wāhitau, me te tau tauranga i roto i te aronga whakamuri ki te kia maheretia raraunga.

Kawa kahore e i hāngai i runga i TCP UDP ranei, e rapu tikanga rerekē o te iritiraa. Mana Karere Kawa Ipurangi (ICMP), rite ki te tikanga, correlates te raraunga tuku ki te hononga tīariari. tikanga o tēnei e kia whakaaturia e ratou te whakamahi i te taua IP-wāhitau, me te whakaturia tau tīmatanga.

Aha e whakaaro ahau?

Whirihora NAT i runga i te pouara kore e hoatu ki a ia te taea o hononga "i pito ki pito." Na reira, e kore e taea e enei pouara whai wāhi i roto i te tahi mau kawa Ipurangi. Ratonga e rapu te tomokanga o te TCP-hononga i te whatunga waho ranei kaiwhakamahi kahore kawa kia wātea. Ki te kore e hanga i te pouara NAT nui kaha ki te tautoko i taua tikanga, e kore e taea e pākete taumai tae ratou ūnga. Ka taea e ētahi kawa hāngai kotahi translation i waenganui i whai wāhi mano ( "aratau hāngū» FTP, mo te tauira), i ētahi wā ki te awhina o kuwaha tono, engari whakapumautia te hononga e ina e wehea pūnaha e rua i te Internet mā te whakamahi i NAT. fakafaingata'a'ia'i hoki Mā te NAT taua "poka" tikanga, pērā i te IPsec, no te mea e taui te reira i te uara i te pane, e taunekeneke ki te tapatahi tono arotake.

Ko te raruraru o nāianei

Pūhui "i pito ki tetahi pito" Ko te parau tumu taketake o te Internet, ngā mai tona whanaketanga. E whakaatu ana te āhua o te whatunga o nāianei e NAT ko te takahi o tenei parau tumu. Mataotao i reira e tino āwangawanga e pā ana ki te whakamahi whānui o IPv6-i roto i te translation wāhitau whatunga, ka whakaara ake te raruraru o te pehea, ki te tōtika faaore i te reira.

No te mea o te natura Rangitahi o tepu stateful pāho Pouara NAT, ngaro nga whakaaro whatunga ā-IP-hononga, rite ki te tikanga, i roto i te wā poto rawa o te wā. I tua atu i te meka e te NAT taua i roto i te pouara, koutou e taea e kore e wareware i tenei meka. Tenei tino whakaiti te wa whakahaere o ngā pūrere kiato e whakahaere i runga i pūhiko me accumulators.

scalability

I tua atu, whaia ka whakamahi i NAT tauranga anake e taea te hohoro mauriora tono ā-whakamahi hononga tukutahi maha (hei tauira, te HTTP-tono mō ngā whārangi tukutuku ki te maha nui o ngā ahanoa tāmau). Ka taea e tenei raruraru te whakangāwari i e te aroturuki i te ūnga IP-wāhitau i roto i te tua ki te tauranga (kupu wehea kotahi tauranga rohe te mano atu mamao).

te tahi mau fifi

Mai wāhitau ā-katoa ke ana rite te iwi whānui, mano waho riro taea ki te kōkiri i te hononga ki te kōpuku ā motuhake, kahore tetahi whirihoranga motuhake i runga i te pātūahi (i te mea ki te anga te hononga ki te tauranga motuhake). Tono pērā i IP-waea, hui ataata, me enei ratonga whai ki te whakamahi i ngā rautaki traversal NAT ki te mahi tikanga.

wāhitau Hoki me translation tauranga (Rapt) te ope, te mau IP-wāhitau o e rerekē i wa wa ki, ki te noho wātea rite te tūmau ki te whakaritea IP-wāhitau o te whatunga kāinga taea. I roto i te parau tumu, e tukua ai te tūmau whakatū ki te mau tonu te hononga. Ahakoa te meka e kore ko te otinga tino tenei te raruraru, i te reira i taea e tetahi atu taputapu whai hua i roto i te täoro o te kaiwhakahaere whatunga ki te whakaoti i te raruraru, me pehea ki te whirihora NAT i te pouara.

Port Wāhitau Translation (PAT)

Cisco Rapt whakatinanatanga he Port Translation Wāhitau (PAT), e whakaatu rave rahi tūmataiti IP-wāhitau rite tetahi o te iwi whānui. taea te whakaatu i ngā wāhitau maha rite te wāhitau, no te mea aroturuki ia o ratou e te tau tauranga. Ka whakamahia e PAT tau tauranga pūtake ahurei i runga i te IP ao roto, ki te wehewehe i te aronga o te whakawhiti raraunga. Enei tau he tau tōpu moka-16. wāhitau ā-Tapeke e taea te whakamaoritia ki te tetahi waho, takahi taea tae 65536. Ko te maha tūturu o tauranga ki e taea te whakaritea he IP-wāhitau kotahi, he pā ana ki 4000. Tikanga, tamata PAT ki te whakaora i te tauranga pūtake "taketake". Ki te he te reira kua i roto i te whakamahi, e whakarite Port Wāhitau Translation te tau tauranga wātea tuatahi timata mai i te timatanga o te rōpū tēnā - 0-511, 512-1023, ranei 1024-65535. A, no te he i reira tauranga wātea ake me i reira he nui ake atu i te kotahi waho IP-wāhitau, ki te nuku PAT ki te muri tamata ki te tautuhi i te tauranga pūtake. tonu ana tēnei tukanga noa i reira he kore ake raraunga e wātea ana.

He whakaatu i ngā wāhitau a whakatinana tauranga Cisco he mahi e fakatahai te wāhitau tauranga pākete poka translation raraunga KIp6 mo IPv4 ipurangiroto. I roto i te meka, he rerekē ōpaki CarrierGrade NAT me DS-Lite, e tautoko ana IP-wāhitau translation / tauranga (me, reira, tautoko te tautuhinga NAT). Ko te kupu, mawehe reira raruraru i roto i te tāutanga, me te tiaki o te hononga, me whakarato hoki whakawhiti tikanga mo IPv6 whakamahinga.

tikanga translation

He maha ngā huarahi ki te whakatinana i te iritiraa o te wāhitau whatunga me tauranga. I roto i te tahi mau tono, nga kawa e whakamahi tono ki te mahi ki a IP-wāhitau, mahi i roto i te whatunga whakamuna, me te tautuhi koe i te wāhitau waho NAT (whakamahia nei te i te tahi atu pito o te hononga), me, ano, ko reira maha e tika ana ki te ako me te whakarōpū i te momo o te tuku. Ko te tikanga i meatia tenei e no te mea ko reira e minaminatia ki te whakatū i te hongere kōrero tika (ranei te whakaora tuku ore o raraunga i roto i te tūmau ranei ki te whakapai ake mahinga) i waenganui i te kiritaki e rua, e rua o nei he o takitahi NAT.

Hoki tenei whakaaro, (pehea ki te whirihora NAT) i roto i te 2003 whakawhanakehia te RFC kawa motuhake 3489 Traversal Simple o UDP whakarato i roto i NATS. I teie mahana, ko reira tawhitotia, no te mea i enei e iti ki tika aromatawai i te mahi o maha nga whakaaro i enei tikanga. Kua tikanga hou te papa'iraa i roto i te kawa RFC 5389, i whakawhanakehia i roto i te nuku 2008. Kei te mohiotia inaianei tenei whakatakotoranga rite SessionTraversal me ko he taputapu mo te NAT.

Te hanga i te kōrero e rua-ara

Kei ia pākete TCP me UDP IP-pūtake wāhitau, me te tau tauranga, me te te taunga o te tauranga ūnga.

Hoki taua ratonga tūmatanui rite te tūmau ī-mēra mahi, he nui te tau tauranga. Hei tauira, tauranga 80 te hono ki te pūmanawa, tūmau tukutuku, me 25 - ki te tūmau mēra SMTP. he faufaa hoki, rite wāhitau poutāpeta tau waea ranei tūmatanui IP-wāhitau te tūmau o te. kia mōhiotia authentically ki ngā kōpuku katoa e e haere ki te hono rua o enei tawhā.

Private IP-wāhitau i mahu'inga anake i roto i whatunga rohe, kei hea e whakamahia ratou, me te tauranga ope. Tauranga he mutunga ahurei hononga pūwāhi i runga i te ope, na te hononga i roto i te NAT tautokona e te mahere tauranga ngā me IP-wāhitau.

PAT (Port AddressTranslation) veteki papā e kia ara ake i waenganui i nga mano rerekē e rua te whakamahi i te tau tauranga pūtake taua ki te whakatū hononga ahurei i te wa ano.