A yau, adadin manyan sabis na DNS da masu kera sabar DNS za su gudanar da taron haɗin gwiwa tsara don mayar da hankali a kan tare da rarrabuwar IP lokacin sarrafa manyan saƙonnin DNS. Wannan shine karo na biyu da irin wannan taron, a bara "ranar tutar DNS" akan daidai sarrafa buƙatun EDNS.
Mahalarta ranar tutar DNS 2020 yunƙurin suna kira don shawarar da aka ba da shawarar masu girma dabam don EDNS da za a daidaita su zuwa 1232 bytes (Girman MTU 1280 da 48 bytes don masu kai), haka kuma aiwatar da buƙatun ta hanyar TCP shine fasalin dole ne akan sabobin. IN Goyon bayan buƙatun sarrafawa ta hanyar UDP ne kawai aka yiwa alama dole, kuma an jera TCP azaman kyawawa, amma ba a buƙata don aiki ba. Sabo и a sarari jera TCP azaman damar da ake buƙata don DNS yayi aiki daidai. Ƙudurin ya ba da shawarar tilasta sauyawa daga aika buƙatun akan UDP zuwa amfani da TCP a lokuta inda girman buffer na EDNS ya kasa isa.
Canje-canjen da aka tsara za su kawar da rikice-rikice tare da zabar girman buffer EDNS da kuma magance matsalar rarrabuwar manyan saƙonnin UDP, wanda sarrafa shi sau da yawa yakan haifar da asarar fakiti da lokaci a gefen abokin ciniki. A gefen abokin ciniki, girman buffer na EDNS zai kasance akai-akai kuma za a aika manyan martani nan da nan ga abokin ciniki akan TCP. Gujewa aika manyan saƙonni akan UDP shima zai magance matsaloli tare da manyan fakitin da aka jefa akan wasu tawul ɗin wuta da ba da damar toshewa. don guba cache na DNS, dangane da magudin fakitin UDP masu ɓarna (lokacin da aka raba cikin gutsuttsauran ra'ayi, guntu na biyu ba ya haɗa da taken da mai ganowa, don haka ana iya ƙirƙira shi, wanda ya isa kawai don checksum ya dace) .
Farawa yau, masu ba da sabis na DNS masu shiga ciki har da CloudFlare, Quad 9, Cisco (OpenDNS) da Google, Girman buffer na EDNS daga 4096 zuwa 1232 bytes akan sabar DNS ɗin sa (canjin EDNS zai bazu cikin makonni 4-6 kuma zai rufe adadin buƙatun akan lokaci). Za a aika da martani ga buƙatun UDP waɗanda basu dace da sabon iyaka ta hanyar TCP ba. Dillalan uwar garken DNS da suka haɗa da BIND, Unbound, Knot, NSD da PowerDNS za su saki sabuntawa don canza tsoho girman buffer EDNS daga 4096 bytes zuwa 1232 bytes.
Daga ƙarshe, waɗannan canje-canje na iya haifar da matsalolin ƙuduri lokacin samun dama ga sabar DNS waɗanda martanin UDP DNS ya wuce 1232 bytes kuma ba zai iya aika martanin TCP ba. Wani gwaji da aka gudanar a Google ya nuna cewa canza girman buffer na EDNS kusan ba shi da wani tasiri akan ƙimar gazawar - tare da buffer na 4096 bytes, adadin buƙatun UDP ɗin da aka yanke shine 0.345%, kuma adadin sakewa da ba a iya kaiwa kan TCP shine 0.115%. Tare da buffer na 1232 bytes, waɗannan alkalumman sune 0.367% da 0.116%. Yin goyon bayan TCP wani fasalin DNS da ake buƙata zai haifar da matsaloli tare da kusan 0.1% na sabar DNS. An lura cewa a cikin yanayi na zamani, ba tare da TCP ba, aikin waɗannan sabobin ya riga ya kasance maras tabbas.
Masu gudanarwa na sabar DNS masu iko su tabbatar da cewa uwar garken su ta amsa ta hanyar TCP akan tashar tashar 53 kuma wannan tashar TCP ba ta toshe ta ta hanyar wuta. Sabar DNS mai suna kuma kada ta aika da martanin UDP waɗanda suka fi girma
girman buffer na EDNS. A kan uwar garken kanta, girman buffer ɗin EDNS yakamata a saita zuwa 1232 bytes. Masu warwarewa suna da kusan buƙatu iri ɗaya - ikon tilas don amsa ta hanyar TCP, tallafi na wajibi don aika buƙatun ta hanyar TCP lokacin karɓar amsawar UDP da aka yanke, da saita buffer EDNS zuwa 1232 bytes.
Simitoci masu zuwa suna da alhakin saita girman buffer EDNS a cikin sabobin DNS daban-daban:
Zaɓuɓɓuka {
edns-udp-size 1232;
max-udp-size 1232;
};
Saukewa: 1232
net.bufsize(1232)
udp-truncation-threshold=1232
edns-outgoing-bufsize=1232
udp-truncation-threshold=1232
Girman edns-buffer: 1232
IPv4-edns-size: 1232
IPv6-edns-size: 1232
source: budenet.ru