Rashin neman sunan mai amfani kyauta ce ta tantancewa: PPP bai fara ba tukuna, don haka ba a tuntuɓi asusu, kalmar sirri ko manufar yanki ba tukuna. A haɗin PPTP ko L2TP/IPsec abokin ciniki yana neman takardun shaida ne kawai bayan ramin ya wanzu kuma uwar garke ta fara zaman PPP. Duk abin da zai iya gazawa kafin wannan lokacin jigilar bayanai ne, musayar maɓalli ko kafa rami, wanda ya fi «VPN ɗin ya lalace» ƙanƙantar fili.

Rashin buƙatar yana taƙaita kuskure zuwa matakai uku

Rubuta matakin ƙarshe da ya yi nasara a bayyane, domin kowanne yana da mai shi dabam da magani dabam. Yin hasashe kan saitin asusu yayin da ka makale matakai biyu baya shi ne yadda rana ta wuce.

StageWhat has to workHow a failure looks
ReachUDP 500, 4500 and 1701 — or TCP 1723 plus GRE — through every firewall and NAT deviceClient hangs, then reports no response
Key exchangePreshared key or certificate, phase 1 and phase 2 proposalsFast error, or a stall after the client says it is verifying
TunnelL2TP or PPTP control channel, then PPP startsConnects, then closes with no prompt
User authPPP credentials and an address pool with roomPrompt appears, then a rejection

Abokin ciniki da ya ƙare ba tare da buƙata ba bai taɓa samun haɗin IPsec ba, don haka kuskuren yana cikin IKE ko cikin ko fakitinku sun isa ƙofar ko a'a. Wanda ya ce yana tabbatar da takardun shaida sannan ya faɗi ya wuce abin da saƙon ke nunawa. Buƙatar da ke biye da ƙi ta PPP ce, kuma wannan ya shafi labarin asusu ne ba wannan ba.

Mataki na ɗaya: ka'idar da bangon wuta ke jefawa a asirce

PPTP na buƙatar TCP 1723 don tashar sarrafawa da ka'idar IP 47 don hanyar bayanai, kuma su biyu suna tafiya dabam. Yawancin cibiyoyin sadarwa suna tura 1723 kuma suna jefar da ka'idar 47, wanda ke haifar da rami da ke yin shawara sannan ba ya ɗaukar komai. Na'urar da ke yin NAT kuma tana buƙatar hanyar wucewa mai goyon bayan GRE, kuma hanyar shiga ta IPv6 kawai ba za ta iya ɗaukar PPTP a kowane tsari ba.

L2TP kan IPsec yana cinye tashar 500 don IKE da tashar 4500 don tsallake NAT, sannan yana naɗe zirga-zirgar L2TP kanta cikin 1701, yayin da ESP ke ɗaukar kayan da aka kare da zarar haɗin ya wanzu. Ka ba da izinin tashoshin sarrafawa biyu amma ba ESP ba, kuma za ka sami ainihin alamar da ke cikin taken: ci gaba da ake gani, sannan mataccen abokin ciniki kafin kowane tattaunawar takardar shaida. Gwaji daga hotspot ɗin waya hanya ce mai arha ta raba matsalar abokin ciniki da matsalar hanya.

Mataki na biyu: maɓalli wanda ba maɓalli ba, shawara da ba a bayar ba

Maɓallin da aka raba tun farko da bai dace ba yana gazawa cikin sauri da shiru, kuma sigar da aka saba ita ce maɓallin da ke kama da daidai a allo yayin da yake ɗauke da tsagawar layin da aka liƙa ko sarari a ƙarshe. A abokin ciniki na Linux ba lallai ba ne tattaunawar ita ce tushen gaskiya: ƙarin L2TP na NetworkManager yana ajiye asirai a fayiloli ƙarƙashin /etc/ipsec.d/, kuma wani tsohon fayil na kowane haɗi wanda /etc/ipsec.secrets har yanzu ya haɗa za a yi amfani da shi maimakon wanda ka yi bugawa yanzu. Kwafi wannan fayil zuwa wuri mai aminci, cire shi daga hanyar haɗawa, sannan ka sake buga maɓallin da hannu.

Sauran rabin wannan mataki shawara ce. Dole bangarorin biyu su amince da tsarin algorithm na mataki 1 ɗaya — ɓoyewa, aminci da gungun Diffie-Hellman — da kuma jujjuyawar ESP da suka dace na mataki 2, in ba haka ba haɗin ba zai samu ba kwata-kwata. Ƙofa da ke bayar da 3DES da SHA1 da MODP1024 kawai za ta ƙi abokin ciniki da aka saita don algorithm mafi ƙarfi, kuma littafinta yana ambaton jujjuyawar da aka ƙi. Littafin yana ambaton rashin daidaituwar idan ka karanta shi maimakon sake kunna sabis ɗin. Maimakon kwafin jerin algorithm daga zaren dandalin tattaunawa, tambayi ƙofar waɗanne jujjuyawa za ta yi shawara da gaske: ike-scan da aka nuna zuwa adireshinta yana mayar da jujjuyawar da za ta yi shawara. Idan tayin ɗaya tilo shine ɓoye-ɓoye da manufarka ba ta ƙara yarda da shi ba, gyaran yana wurin ƙofar ne, ba a rage abokin ciniki ba.

A Windows maɓallin da hanyar tabbatarwa suna zaune a cikin bayanin martabar VPN, kuma rashin daidaituwa yana bayyana kafin neman takardar shaida ba bayansa ba. Inda mai karɓa Windows Server ne, tabbatar an shigar da aikin samun dama daga nesa, cewa takardar shaidar ta dace da sunan da abokan ciniki ke haɗawa da shi, kuma babu matattarar tasha da ta fi ƙunci fiye da ka'idodin da ke sama.

Mataki na uku: ramin yana nan kuma PPP ba ya farawa

Lokacin da IKE ya kammala kuma buƙatar ba ta bayyana ba har yanzu, duba aljaniyar rami maimakon bangon wuta. L2TP na buƙatar wani abu da ke saurare a UDP 1701 — xl2tpd ko kl2tpd a Linux, sabis ɗin samun dama daga nesa a Windows — kuma sabis ɗin da aka shigar amma aka tsayar yana kama da fakitin da aka jefa daga wajen abokin ciniki. Duba mai saurare kafin ka sake buɗe dokokin da ka riga ka tabbatar. Sannan PPP dole ne ya yi shawara, kuma musayar LCP ta farko ita ce wurin da gazawar shiru ke sauka akai-akai.

Tarko ɗaya a wannan mataki ba kuskuren cibiyar sadarwa ba ne kwata-kwata: Windows yana ba da izinin haɗi ɗaya na wani nau'in VPN a lokaci ɗaya, don haka ƙoƙari na biyu yana mayar da kuskure 937, «wani haɗi na wannan nau'in yana aiki». Wannan doka ce ta gida, kuma hanyar kaucewa ita ce wata na'ura, wani nau'in rami, ko raba haɗin guda ɗaya da ya riga ya wanzu.

Karanta littafin a jerin matakai maimakon yin hasashe

Tsayar da abokin ciniki, sake kunna shi, kuma karanta sassan a jerin da suke rubuta littafi. Wato da farko aljaniyar IPsec — strongSwan ko Libreswan, kuma ipsec --version yana gaya maka wanne — sannan aljaniyar L2TP, sannan pppd. Duk sassan da ya rubuta na ƙarshe kafin gazawar shine ke nuna matakin da za a bincika, domin duk abin da ya zo bayansa a jerin bai gudana ba kwata-kwata.

Tabbatar da sabon haɗi maimakon zaman da aka ajiye, domin abokin ciniki da ke sake haɗawa daga ajiyar yana iya tsallake sassan musayar kuma ya sake haifar da tsohon sakamako. Tabbatar da isa, musayar maɓalli, rami da PPP ɗaya bayan ɗaya, a wannan jeri. Sannan rashin buƙatar ya daina zama asiri kuma ya zama layi na biyu na jerin da za ka iya aiki da shi da gaske. Wannan jerin kuma shine abin da kake ba ƙungiyar cibiyar sadarwa, waɗanda in ba haka ba za a nemi su duba bangon wuta don kuskuren da ke zaune a cikin aljaniyar da ba a kunna ba.

Labarai masu alaƙa