Nhanganyaya
Tose tinoziva musimboti wekupatsanura uye kusapatsanura IP uye mashandisirwo ayo mukutaurirana kwenetiweki. Kupatsanura IP uye kuunganidzazve inzira yakakosha mukufambisa mapaketi. Kana saizi yepaketi ikapfuura muganho wepamusoro weChikamu chekutumira (MTU) che network link, kupatsanura IP kunopatsanura paketi kuita zvidimbu zvidiki zvakawanda zvekutapurirana. Zvidimbu izvi zvinotapurirwa zvakazvimiririra mu network uye, kana zvasvika panzvimbo yazvinenge zvichienda, zvinounganidzwazve kuita mapaketi akazara ne IP reassembly mechanism. Maitiro aya ekupatsanura uye kuunganidzazve anovimbisa kuti mapaketi makuru anogona kutapurirwa mu network uku tichiona kuti data rakavimbika uye rakavimbika. Muchikamu chino, tichatarisa zvakadzama kuti kupatsanura IP uye kuunganidzazve zvinoshanda sei.
Kupatsanurwa kweIP uye Kubatanidzwazve
Ma "data links" akasiyana ane ma "maximum transmission units" akasiyana (MTU); semuenzaniso, FDDI data link ine MTU ine ma "bytes" 4352 uye Ethernet MTU ine ma "bytes" 1500. MTU inomirira Maximum Transmission Unit uye inoreva saizi yepamusoro yepaketi inogona kutumirwa kuburikidza netiweki.
FDDI (Fiber Distributed Data Interface) imhando ye network yenzvimbo (LAN) inoshandisa fiber ye optical senzira yekutumira data. Maximum Transmission Unit (MTU) ndiyo saizi yepaketi yepamusoro inogona kutumirwa neprotocol ye data link layer. Muma network eFDDI, saizi yeMTU i4352 bytes. Izvi zvinoreva kuti saizi yepaketi yepamusoro inogona kutumirwa neprotocol ye data link layer muFDDI network i4352 bytes. Kana packet ichatumirwa ikadarika saizi iyi, inofanira kupatsanurwa kuti packet iite zvidimbu zvakawanda zvakakodzera saizi yeMTU yekutumirwa uye kuunganidzwa pa receiver.
Kune Ethernet, MTU inowanzova nehukuru hwemabyte 1500. Izvi zvinoreva kuti Ethernet inogona kutumira mapaketi anosvika 1500 bytes. Kana saizi yepaketi ikadarika muganho weMTU, ipapo paketi inopatsanurwa kuita zvidimbu zvidiki kuti itumirwe uye inosanganiswazve panzvimbo yainoda. Kubatanidzazve datagram yeIP yakapatsanurwa kunogona kuitwa chete nehost yenzvimbo, uye router haizoiti basa rekubatanidzazve.
Takataurawo nezvezvikamu zveTCP kare, asi MSS inomiririra Maximum Segment Size, uye inoita basa rakakosha muTCP protocol. MSS inoreva saizi yechikamu chikuru chedata chinotenderwa kutumirwa muTCP connection. Kufanana neMTU, MSS inoshandiswa kudzikamisa saizi yemapaketi, asi inoita izvozvo pa transport layer, iyo TCP protocol layer. TCP protocol inotumira data re application layer nekukamura data muzvikamu zvakawanda zvedata, uye saizi yechikamu chega chega chedata inoganhurirwa neMSS.
MTU yedata link yega yega yakasiyana nekuti mhando yega yega yedata link inoshandiswa pazvinangwa zvakasiyana. Zvichienderana nechinangwa chekushandisa, maMTU akasiyana anogona kuchengetwa.
Ngatitii mutumiri anoda kutumira datagram hombe ye4000 byte kuti itumirwe kuburikidza neEthernet link, saka datagram inofanira kupatsanurwa kuita datagram nhatu diki kuti itumirwe. Izvi zvinodaro nekuti saizi yedatagram imwe neimwe diki haigone kudarika muganho weMTU, unova 1500 bytes. Mushure mekugamuchira datagram nhatu diki, mugamuchiri anodzibatanidzazve kuita datagram hombe ye4000 byte yekutanga zvichibva panhamba yekutevedzana uye kuderedzwa kwedatagram yega yega.
Mukutumira kwakapatsanurwa, kurasikirwa nechidimbu kuchaita kuti datagram yese yeIP isashande. Kuti izvi zvisaitike, TCP yakaunza MSS, uko kupatsanurwa kunoitwa paTCP layer kwete neIP layer. Chakanakira nzira iyi ndechekuti TCP ine kutonga kwakanyatsojeka pamusoro pehukuru hwechikamu chimwe nechimwe, izvo zvinodzivirira matambudziko ane chekuita nekupatsanurwa paIP layer.
Kune UDP, tinoedza kusatumira data packet yakakura kupfuura MTU. Izvi zvinodaro nekuti UDP inzira yekufambisa isina kubatana, iyo isingape kuvimbika uye nzira dzekutumira data zvakare seTCP. Kana tikatumira data packet yakakura kupfuura MTU, ichapatsanurwa neIP layer yekutumira data. Kana chimwe chezvidimbu charasika, UDP protocol haigone kutumira data zvakare, zvichikonzera kurasikirwa nedata. Saka, kuti tive nechokwadi chekuti data rakavimbika, tinofanira kuedza kudzora saizi yemapaketi edata eUDP mukati meMTU uye kudzivirira kutapurirana kwacho.
Mutengesi wePaketi yeMambure eMylinking ™inogona kuziva otomatiki mhando dzakasiyana dzeprotocol yemugero VxLAN/NVGRE/IPoverIP/MPLS/GRE, nezvimwewo, inogona kutsanangurwa zvichienderana neprofile yemushandisi zvichienderana nekubuda kwemugero wemukati kana wekunze.
○ Inogona kuziva mapaketi eVLAN, QinQ, uye MPLS
○ Anogona kuziva VLAN yemukati neyekunze
○ Mapaketi eIPv4/IPv6 anogona kuzivikanwa
○ Inogona kuziva mapaketi eVxLAN, NVGRE, GRE, IPoverIP, GENEVE, MPLS
○ Mapaketi Akapatsanurwa eIP anogona kuzivikanwa (Kuzivikanwa kwezvikamu zveIP zvinotsigirwa uye kunotsigira kubatanidzwazve kwezvikamu zveIP kuitira kuti pave nekusefa kweL4 feature pamapaketi ese ezvikamu zveIP. Shandisa mutemo wekubuda kwetraffic.)
Sei IP yakakamurwa uye TCP yakakamurwa?
Sezvo mukutumira kwenetiweki, IP layer ichaparadzanisa data otomatiki, kunyangwe TCP layer isingapatsanure data, data packet ichapatsanurwa otomatiki neIP layer uye ichatumirwa zvakajairika. Saka sei TCP ichida kupatsanurwa? Hazvisi zvekunyanyisa here izvozvo?
Ngatitii pane paketi hombe isina kupatsanurwa paTCP layer uye inorasika pakufamba; TCP ichaitumirazve, asi mupaketi hombe yese chete (kunyangwe IP layer ichikamura data kuita mapaketi madiki, rimwe nerimwe rine urefu hweMTU). Izvi zvinodaro nekuti IP layer haina hanya nekutumirwa kwedata kwakavimbika.
Nemamwe mashoko, pakutakurwa kwemuchina kuenda kune network link, kana transport layer ikapwanya data, IP layer haiipwanye. Kana fragmentation isina kuitwa pa transport layer, fragmentation inogoneka pa IP layer.
Muchidimbu, TCP inopatsanura data kuitira kuti IP layer isaparare, uye kana data radzoserwa, zvikamu zvidiki chete zvedata radzoserwa zvinotumirwazve. Nenzira iyi, kushanda zvakanaka uye kuvimbika kwedata kunogona kuvandudzwa.
Kana TCP yakakamurwa, ko IP layer haina kupatsanurwa here?
Muhurukuro yataurwa pamusoro apa, takataura kuti mushure mekupatsanurwa kweTCP pamutumi, hapana kupatsanurwa kweIP layer. Zvisinei, panogona kunge paine mimwe midziyo ye network layer mukati me transport link inogona kunge iine maximum transmission unit (MTU) diki pane MTU pamutumi. Saka, kunyangwe packet yakapatsanurwa pamutumi, inopatsanurwa zvakare painopfuura nepakati peIP layer yemidziyo iyi. Pakupedzisira, zvidimbu zvese zvichaunganidzwa pamugamuchiri.
Kana tikakwanisa kuona MTU shoma pane chinongedzo chose totumira data pakureba ikoko, hapana kupatsanurwa kuchaitika zvisinei nekuti data rinotumirwa kupi. Iyi MTU shoma pane chinongedzo chose inonzi nzira yeMTU (PMTU). Kana packet yeIP yasvika parouter, kana MTU yerouter iri pasi pehurefu hwepacket uye mureza weDF (Do not Fragment) waiswa pa1, router haizokwanisi kupatsanurwa packet uye inogona kungoidonhedza chete. Muchiitiko ichi, router inogadzira meseji yekukanganisa yeICMP (Internet Control Message Protocol) inonzi "Kupatsanurwa Kunodiwa Asi DF Set." Iyi meseji yekukanganisa yeICMP ichadzoserwa kukero yekwakabva ine kukosha kweMTU kwerouter. Kana mutumiri agamuchira meseji yekukanganisa yeICMP, inogona kugadzirisa saizi yepacket zvichibva paMTU value kuitira kudzivirira mamiriro ekupatsanurwa akarambidzwa zvakare.
Kupatsanurwa kweIP chinhu chakakosha uye chinofanira kudzivirirwa paIP layer, kunyanya pamidziyo yepakati iri mu link. Saka, mu IPv6, kupatsanurwa kwemapaketi eIP nemidziyo yepakati kwakarambidzwa, uye kupatsanurwa kunogona kuitwa chete pakutanga nepakuguma kwe link.
Kunzwisisa Kwepakutanga kweIPv6
IPv6 ishanduro yechitanhatu yeInternet Protocol, inova ndiyo inotsiva IPv4. IPv6 inoshandisa kureba kwekero ye128-bit, iyo inogona kupa ma IP address akawanda kupfuura kureba kwekero ye32-bit yeIPv4. Izvi zvinodaro nekuti nzvimbo yekero yeIPv4 inopera zvishoma nezvishoma, nepo nzvimbo yekero yeIPv6 yakakura kwazvo uye inogona kusangana nezvinodiwa neInternet yeramangwana.
Kana tichitaura nezve IPv6, pamusoro penzvimbo yakawanda yekero, inounzawo kuchengetedzeka kuri nani uye kugona kukura, zvinoreva kuti IPv6 inogona kupa ruzivo rwenetwork rwuri nani zvichienzaniswa neIPv4.
Kunyangwe IPv6 yagara iripo kwenguva yakareba, kushandiswa kwayo pasi rose kuchiri kunonoka. Izvi zvinonyanya kuitika nekuti IPv6 inofanirwa kuenderana neIPv4 network iripo, iyo inoda shanduko nekutama. Zvisinei, nekuneta kwekero dzeIPv4 uye kudiwa kuri kuwedzera kweIPv6, makambani akawanda epa internet nemasangano ari kushandisa IPv6 zvishoma nezvishoma, uye zvishoma nezvishoma ari kuona mashandiro maviri eIPv6 neIPv4.
Pfupiso
Muchitsauko chino, takaongorora zvakadzama mashandiro anoita IP fragmentation uye reassembly. Data links dzakasiyana dzine Maximum Transmission Unit (MTU) yakasiyana. Kana saizi yepaketi ikadarika muganho weMTU, IP fragmentation inokamura packet kuita zvidimbu zvidiki zvakawanda zvekutapurirana, uye inozozvibatanidzazve kuita packet yakazara neIP reassembly mechanism mushure mekusvika kwainoenda. Chinangwa chekukamura kweTCP ndechekuita kuti IP layer isazove fragment, uye kutumirazve data diki rakakamurwa kana retransmission yaitika, kuitira kuvandudza kushanda kwetransmission uye kuvimbika. Zvisinei, panogona kunge paine mimwe network layer devices mukati me transport link iyo MTU ingave diki pane yemutumiri, saka packet icharamba yakakamurwa zvakare paIP layer yemidziyo iyi. Kukamurwa paIP layer kunofanira kudzivirirwa zvakanyanya sezvinobvira, kunyanya pamidziyo yepakati iri mu link.
Nguva yekutumira: Nyamavhuvhu-07-2025
