mDNS ngaphakathi kwe-VPN: kungani amagama .local engaxazululeki

Umshicileli wehhovisi lakho uvela kuyo yonke i-app etafuleni lakho futhi unyamalala ku-VPN, nakuba ungakwazi ukupinga ikheli ohlale wazi ukuthi unalo. Akukho okonakele emhubheni: ukuthola nokufinyeleleka kuyizinsizakalo ezihlukene, futhi ngokukhula okukodwa kuphela kuzo okuwela umhubhe onemizila. Izinsuku ezingezansi ziyahlukanisa ngaphambi kokuthi uqale ukwengeza imizila. Umzila awukwazi ukulungisa umbuzo ongakaze ushiye isixhumanisi.

Hlola ukuthi yini exazulukayo namuhla, nokuthi yini ebonakala nje sengathi ixazulukile

Qala ngokuhlukanisa imibuzo emibili: umbuzo we-unicast wegama lomsingathi ubuza isixazululi, kuyilapho ukusesha _ipp._tcp kubuza isixhumanisi sasendaweni. Ku-Linux, avahi-browse -a ukhombisa lokho i-multicast DNS engakubona, futhi resolvectl query name.local ukhombisa lokho isitaki sesixazululi esikwenzayo ngalelo gama. Ku-macOS, dns-sd -B _ipp._tcp ubala izinsizakalo ezitholiwe ngaphandle kokudinga ikheli kuqala.

Uma ikheli liphendula kanti igama aliphenduli, ukuhamba kwemizila kuyasebenza kanti ukuthola akusebenzi. Igama le-.local lingaphendulwa futhi kusisingathi uqobo nge-nss-mdns ngaphandle kokuthi i-avahi-browse ifakiwe, ngakho-ke i-getent noma ipingi eliphumelelayo kulelo gama akusona ubufakazi bokuthi ukuthola kwawela umhubhe; umphumela wokusesha nowesixazululi ubufakazi obuhlukene. Izinhlelo zilondoloza kusikhashana lokho ezikutholile, yingakho ukwehluleka kuvame ukuvela emahoreni ngemva kokuxhuma hhayi ngesikhathi sokuxhuma. Vala bese uvula kabusha uhlelo, bese uhlola ukuthi okufakiwe kusikhashana kunegama noma ikheli, ngoba ikheli liqhubeka lisebenza isikhathi eside ngemuva kokuthi ukuthola kume.

Kungani umbuzo ungaweli umhubhe neze

I-multicast DNS ithumela imibuzo ku-224.0.0.251, ngaphakathi kwebhlokhi yokulawula inethiwekhi yasendaweni, kuphothi le-UDP 5353. Amarutha awadlulisi amakheli avela kulelo bhlokhi, ngakho umbuzo uhlala kusixhumanisi okwathunyelwa kuso. Abathumeli babeka ne-IP TTL, noma umkhawulo wokugxuma we-IPv6, ku-255 ukuze umamukeli akwazi ukwenqaba iphakethe eselivele ladlula irutha; yileyo ndlela iphrothokholi ithola ubuqili obungaphandle kwesixhumanisi, hhayi ngale ndlela ehlala yasendaweni. Isimo sasendaweni sivela ekhelini lomkhombandlela, hhayi ku-TTL yokugxuma okukodwa.

Uhlobo lomhubhe nalo lubalulekile. Isixhumanisi sesitayela se-tun sithwala amaphakethe e-IP kuphela, hhayi enye into, ngakho alikho iqembu le-multicast elisindayo kulo. Ibhuloho lesitayela se-tap landisa isizinda sokusakaza ngokwalo, yingakho ezinye izakhiwo zakudala zenza ibhuloho esikhundleni semizila, futhi zazuza njengefa zonke izinkinga ezilethwa ibhuloho.

Ukuhlukile kwe-LAN ethembekile akushintshi lutho kulokhu, ngoba kunquma ukuthi ikuphi ukuhamba okuvunyelwe ukusebenzisa umhubhe esikhundleni sokufundisa umhubhe ukudlulisa i-multicast. Iphakethe alikabi naso isigaba esabiwe lapho lingezwakala khona.

Khetha uhlobo lokuqamba amagama ongalugcina

Ezimayini zenkampani, impendulo eqinile igama lomsingathi elinemithelela elisetshenziswa isixazululi esicindezelwa i-VPN, kanye ne-DNS ehlukanisiwe ukuze amagama angaphakathi aye kumaseva angaphakathi kanti konke okunye kungenzi. I-Windows ikubonisa njengethebula lenqubomgomo yokuxazulula amagama, i-macOS isebenzisa izixazululi ezinomkhawulo ngasinye isixhumanisi, futhi iningi lamaklayenti linokulungiselela kokucindezela okulinganayo. Idivayisi igcina igama layo elijwayelekile ku-DNS yangaphakathi, futhi ukuthola kuyeka ukuba yingxenye yomzila.

Ummeleli wokuthola noma isibonisi se-mDNS angaxhumanisa leli gebe, futhi lolu wuhlelo lwangempela olunomsingathi walo, ukuchayeka kwalo nezidingo zeklayenti zalo. Aliveli ngoba wengeze umzila. Ungalokothi udlulise imibuzo ye-.local kusixazululi somphakathi: isizinda sigcinelwe ukusetshenziswa kwe-multicast yasendaweni yi-RFC 6762, futhi ukusithumela ngaphandle kuletha ukwehluleka okunensayo nokudalulwa kwedatha okungadingekile.

Qinisekisa insizakalo, hhayi igama

Igama ohlwini lokusesha lifakazela isinyathelo sokuthola, hhayi ukuthi insizakalo iyaphendula. Vula umugqa wokuphrinta noma isixhumanisi sewebhu bese uqedela umsebenzi wangempela, bese ukuphinda ngemva kokuxhuma kabusha.

Ukuthola kubhulunga amagama esikhashaneni ngamandla, ngakho okungenisiwe okudala kungabonakala njengempumelelo. Uma kuvela isitifiketi noma isicelo sokuqinisekisa, leso yisigaba esilandelayo futhi inkinga ehlukile. Bhala ukuthi yiluphi uhlobo lwendlela oyishintshile, isixazululi noma ukuthola, ukuze umuntu olandelayo angadingi ukuvula ingxoxo yonke futhi.