169.254 nge-VPN: ikheli lalingakaze likwazi ukuhanjiswa ngomzila
Indawo okuyiwa kuyo ye-link-local iyalahlwa ngaphambi kokuba ifinyelele umhubhe, ngakho ukwengeza imizila kwandisa kuphela ukwehluleka. Khetha phakathi kokulungisa i-subnet nokwakha ibhuloho.
Ufaka umzila, umhubhe uyaphakama, kodwa i-ping eya kolunye uhlangothi isafa ngokulahlekelwa okuphelele esikhundleni se-«network unreachable». Lo mehluko ubalulekile, ngoba uqondisa amehlo isuka kuthebula lemizila iye kukheli ngokwalo. Indawo ye-169.254 yi-link-local, futhi ububanzi bayo buphela ku-hop yokuqala ngokomklamo, hhayi ngenxa yokulungiselelwa okungalungile.
Isinqumo esilandelayo sincane futhi kufanelekile ukuthathwa ngokusobala: lungisa i-subnet ohlangothini lwesiphakeli, noma unwebe ingxenye yesigaba sesi-2 ukuze ikheli liphinde libe nencazelo yendawo. Konke okunye, kuhlanganise nomzila obanzi, kwenza kuphela ukwehluleka okufanayo kusebenze ezindaweni eziningi.
Ikheli alinamzila, alikwazi ukuhanjiswa ngomzila
Amakheli e-IPv4 link-local azinika wona lapho kungekho okungcono okuphendulayo; yilapho kuvela khona ukunikezwa kwamakheli ayimfihlo okuzenzakalelayo ku-Windows kanye nokufanayo kwezinye izinhlelo. Ububanzi busetshenziswa kukho konke ukuxhumana ngasikhathi sinye, futhi yikho okwenza kusebenze: amahost amabili engxenyeni efanayo angakhuluma ngaphandle kokuxhumanisa.
Leso sici esifanayo senza ukuthi umhambisi womzila angakwazi ukudlulisa lawa maphakethe phakathi kwamanethiwekhi. Ukwamukela iphakethe eliqondiswe endaweni ye-link-local bese ulikhiphela ngaphandle ngenye i-interface kungadala ukungacaci, ngoba «kwendawo» komthumeli nokomamukeli yizindawo ezihlukene. Akukho ukusesha okungaquma ukuthi iyiphi kulezi ezimbili eyayishiwo umthumeli. Ukudlulisa lapha akusona isinqumo senqubomgomo umphathi angasivula; isigaba sekheli siyakwenqabela.
Ngakho isango elifaka i-169.254.1.10 njengelifinyeleleka ngomhubhe licela i-kernel into eyenqatshwa uhlobo lwekheli. Iphakethe liyalahlwa kude ngaphambi kokuba lifinyelele ihhost ekude, futhi akukho ukunemba komzila okushintsha lowo mphumela.
Kungani umhubhe uveza inkinga yobubanzi
I-interface ye-TUN ithwala amaphakethe e-IP phakathi kwababili futhi ayinayo ingxenye eyabiwe ngemuva kwayo. Akukho ukusakaza, akukho ARP ohlangothini olunye, futhi akukho ukutholwa komakhelwane okungaguqula indawo ye-link-local ibe ikheli lesigaba sokuxhumana.
Izimpawu zihambisana kahle uma wazi ukuthi ufunani. Umzila ukhona kuthebula, i-ping ibika ukulahlekelwa okuphelele esikhundleni senethiwekhi engafinyeleleki, futhi ithebula lomakhelwane libonisa okufakiwe okungaphelele noma okwehlulekile. Ukurekhoda kumhubhe kubonisa iphakethe liphuma, futhi lokho kuqondisa abantu ekupheleni okude esikhundleni sesigaba sekheli.
Ku-Windows kunesici sesibili, esibonakala singahlobene, esinomsuka ofanayo: i-adaptha esele inekheli le-link-local kuphela ayinasango elisebenzisekayo, ngakho ukuhlonza inethiwekhi akukwazi ukuhlukanisa ukuxhumana futhi iphrofayili ye-firewall iwela ku-public. Umhubhe akusona imbangela; ikheli liyimbangela.
Quma ngemibuzo emithathu
Ukukhetha phakathi kokulungisa i-subnet nokwenza ibhuloho kuncike ezimweni ezintathu, futhi noma isiphi sazo singakunquma ngaphambi kokuba uvule ifayela lokulungiselela.
| Question | If yes | If no |
|---|---|---|
| Can the far-side host be given a routable address? | Change the host or fix DHCP and route normally | Continue to the next question |
| Does the device accept a static address at all? | Assign one from the site's real prefix | Bridging is the only remaining option |
| Can you accept broadcast crossing the tunnel? | A bridge is viable for a small segment | Replace the device or accept no remote access |
Izigameko eziningi ziyama embuzweni wokuqala. Ihhost ebonisa ikheli le-link-local ngokuvamile isho ukuthi i-DHCP ayiphendulanga, ukuthi intambo noma i-VLAN ayilungile, noma ukuthi othile wabhala ikheli ngesandla. Ukulungisa lokho kushibhile kunanoma yimuphi umsebenzi womhubhe, futhi kususa inkinga kumakhasimende akusasa wonke, hhayi lena kuphela.
Hlola uhlangothi lwesiphakeli ngaphambi kokucabanga noma yini. Gijimisa i-ip addr show ne-ip route kuhhost, ne-arp -n noma i-route print -4 kukhasimende, ukuze ubone ukuthi isiqalo sikhona ngempela noma ukufakiwe okudala kusho kanjalo.
Ibhuloho libiza malini lapho liyimpendulo efanele
Ukwenza ibhuloho phakathi kwe-adaptha yomzimba ne-adaptha ye-TAP kwenza ikhasimende elikude libe yingxenye yesifunda sokusakaza sendawo. Ngaleso sikhathi ukusakaza nokutholwa komakhelwane kuyasebenza, futhi ikheli le-link-local liphinde libe nencazelo ngoba ikhasimende likwindawo ngempela kulolo xhumano.
Izindleko zingempela futhi kufanele zishiwo ngaphambi kokuba othile avume. Ukuxhumana kokusakaza kweqa umhubhe, ikhasimende lichayeka engxenyeni yendawo ngayo yonke inhloso hhayi izinsizakalo ezizidingayo kuphela, futhi isiphakeli manje kufanele sidlulise ama-frame esikhundleni sokuhambisa amaphakethe ngomzila. Lokhu kuwukushintshana okunengqondo kubhentshi yaselabhorethri noma idivayisi engenayo indlela yokulungiselela ehambisekayo, futhi kuwukuhlela okuyisisekelo okubi kokufinyelela kude.
Uma wenza ibhuloho, izingxenye zombili ziyadingeka: ibhuloho kusiphakeli kanye nomzila kuphrofayili yekhasimende otshela ukuthi iziphi izindawo ezakwelinye uhlangothi. Ibhuloho lodwa lishiya ikhasimende liqagela, futhi umzila wodwa awukwazi ukulungisa isigaba sekheli.