Cov cuab yeej siv feem ntau rau kev saib xyuas thiab daws teeb meem hauv network niaj hnub no yog Switch Port Analyzer (SPAN), tseem hu ua Port mirroring. Nws tso cai rau peb saib xyuas cov tsheb khiav hauv network hauv bypass out of band mode yam tsis cuam tshuam nrog cov kev pabcuam ntawm lub network nyob, thiab xa ib daim qauv ntawm cov tsheb khiav uas tau saib xyuas mus rau cov khoom siv hauv zos lossis chaw deb, suav nrog Sniffer, IDS, lossis lwm hom cuab yeej tshuaj xyuas network.
Qee qhov kev siv ib txwm muaj yog:
• Kho cov teeb meem hauv network los ntawm kev taug qab kev tswj hwm/cov thav duab ntaub ntawv;
• Tshawb xyuas qhov latency thiab jitter los ntawm kev saib xyuas VoIP packets;
• Tshawb xyuas qhov latency los ntawm kev saib xyuas kev sib cuam tshuam hauv network;
• Tshawb nrhiav qhov txawv txav los ntawm kev saib xyuas cov tsheb khiav hauv network.
SPAN Tsheb khiav tuaj yeem raug mirrored hauv zos rau lwm qhov chaw nres nkoj ntawm tib lub cuab yeej qhov chaw, lossis mirrored deb rau lwm cov khoom siv network uas nyob ib sab ntawm Txheej 2 ntawm lub cuab yeej qhov chaw (RSPAN).
Niaj hnub no peb yuav tham txog thev naus laus zis saib xyuas kev khiav tsheb hauv Is Taws Nem hu ua ERSPAN (Encapsulated Remote Switch Port Analyzer) uas tuaj yeem xa mus rau peb txheej ntawm IP. Qhov no yog kev txuas ntxiv ntawm SPAN mus rau Encapsulated Remote.
Cov ntsiab cai ua haujlwm yooj yim ntawm ERSPAN
Ua ntej, cia peb saib cov yam ntxwv ntawm ERSPAN:
• Ib daim qauv ntawm cov pob ntawv los ntawm qhov chaw nres nkoj raug xa mus rau lub server xa ntawv rau kev txheeb xyuas los ntawm Generic Routing Encapsulation (GRE). Qhov chaw nyob ntawm lub server tsis raug txwv.
• Nrog kev pab los ntawm Tus Neeg Siv Txhais Field (UDF) feature ntawm lub chip, txhua qhov offset ntawm 1 txog 126 bytes yog ua raws li Base domain los ntawm cov kws tshaj lij-qib daim ntawv teev npe, thiab cov lus tseem ceeb ntawm kev sib tham tau phim kom paub txog kev pom ntawm kev sib tham, xws li TCP peb txoj kev sib tuav tes thiab RDMA kev sib tham;
• Kev txhawb nqa qhov chaw ntsuas tus nqi;
• Txhawb nqa qhov ntev ntawm kev cuam tshuam pob ntawv (Packet Slicing), txo qhov kev nyuaj siab rau lub server.
Nrog cov yam ntxwv no, koj tuaj yeem pom vim li cas ERSPAN yog ib qho cuab yeej tseem ceeb rau kev saib xyuas cov tes hauj lwm hauv cov chaw khaws ntaub ntawv niaj hnub no.
ERSPAN lub luag haujlwm tseem ceeb tuaj yeem muab faib ua ob ntu:
• Kev Pom Kev Sib Tham: Siv ERSPAN los sau tag nrho cov kev sib tham TCP tshiab thiab Remote Direct Memory Access (RDMA) uas tau tsim rau lub server back-end kom pom;
• Kev daws teeb meem hauv network: Sau cov ntaub ntawv khiav hauv network rau kev tshuaj xyuas qhov yuam kev thaum muaj teeb meem hauv network.
Yuav ua li no, lub cuab yeej network qhov chaw yuav tsum lim cov tsheb khiav uas tus neeg siv xav tau los ntawm cov ntaub ntawv loj heev, ua ib daim qauv, thiab muab txhua daim qauv luam rau hauv ib lub thawv "superframe" tshwj xeeb uas nqa cov ntaub ntawv ntxiv txaus kom nws tuaj yeem xa mus rau lub cuab yeej txais. Ntxiv mus, ua kom lub cuab yeej txais tuaj yeem rho tawm thiab rov qab tau tag nrho cov tsheb khiav uas tau saib xyuas thawj zaug.
Lub cuab yeej txais yuav yog lwm lub server uas txhawb nqa decapsulating ERSPAN packets.
Kev Tshuaj Xyuas Hom ERSPAN thiab Hom Ntawv Pob Khoom
Cov pob ntawv ERSPAN raug kaw siv GRE thiab xa mus rau txhua qhov chaw nyob IP hla Ethernet. Tam sim no ERSPAN feem ntau siv rau ntawm IPv4 networks, thiab kev txhawb nqa IPv6 yuav yog qhov yuav tsum tau muaj yav tom ntej.
Rau cov qauv encapsulation dav dav ntawm ERSAPN, cov hauv qab no yog daim iav pob ntawv ntes ntawm ICMP pob ntawv:
Tus txheej txheem ERSPAN tau tsim kho ntev heev, thiab nrog kev txhim kho ntawm nws cov peev xwm, ntau cov qauv tau tsim, hu ua "ERSPAN Hom". Cov Hom sib txawv muaj cov qauv taub hau sib txawv.
Nws tau txhais nyob rau hauv thawj daim teb Version ntawm ERSPAN header:
Ntxiv mus, daim teb Protocol Type hauv GRE header kuj qhia txog ERSPAN Type sab hauv. Daim teb Protocol Type 0x88BE qhia txog ERSPAN Type II, thiab 0x22EB qhia txog ERSPAN Type III.
1. Hom I
Lub thav duab ERSPAN ntawm Hom I encapsulates IP thiab GRE ncaj qha hla lub header ntawm daim iav thawj. Qhov encapsulation no ntxiv 38 bytes hla lub thav duab thawj: 14 (MAC) + 20 (IP) + 4 (GRE). Qhov zoo ntawm hom ntawv no yog tias nws muaj qhov loj me me ntawm lub header thiab txo tus nqi ntawm kev xa xov. Txawm li cas los xij, vim nws teeb tsa GRE Flag thiab Version teb rau 0, nws tsis nqa cov teb txuas ntxiv thiab Hom I tsis siv dav, yog li tsis tas yuav nthuav dav ntxiv.
GRE header hom ntawv ntawm Hom I yog raws li nram no:
2. Hom II
Hauv Hom II, cov teb C, R, K, S, S, Recur, Flags, thiab Version hauv GRE header yog 0 tag nrho tshwj tsis yog S teb. Yog li ntawd, daim teb Sequence Number tau tshwm sim hauv GRE header ntawm Hom II. Ntawd yog, Hom II tuaj yeem ua kom ntseeg tau qhov kev txiav txim ntawm kev txais cov pob ntawv GRE, yog li ntawd ntau cov pob ntawv GRE uas tsis raws cai tsis tuaj yeem raug txheeb xyuas vim muaj qhov yuam kev hauv network.
GRE header hom ntawv ntawm Hom II yog raws li nram no:
Ntxiv rau, hom ntawv ERSPAN Type II ntxiv 8-byte ERSPAN header ntawm GRE header thiab thawj daim duab mirrored.
Cov hom ntawv ERSPAN header rau Hom II yog raws li nram no:
Thaum kawg, tam sim ntawd tom qab daim duab thawj, yog tus qauv 4-byte Ethernet cyclic redundancy check (CRC) code.
Nws yog ib qho tsim nyog sau tseg tias thaum siv, daim iav tsis muaj daim teb FCS ntawm daim iav qub, es tsis txhob muaj tus nqi CRC tshiab raug suav dua raws li tag nrho ERSPAN. Qhov no txhais tau tias lub cuab yeej txais tsis tuaj yeem txheeb xyuas qhov tseeb ntawm CRC ntawm daim iav qub, thiab peb tsuas tuaj yeem xav tias tsuas yog cov thav duab tsis puas tsuaj thiaj li raug iav.
3. Hom III
Hom III qhia txog lub taub hau sib xyaw ua ke loj dua thiab yoog tau dua los daws cov teeb meem kev saib xyuas network uas nyuaj thiab sib txawv, suav nrog tab sis tsis txwv rau kev tswj hwm network, kev tshawb pom kev nkag mus, kev ua tau zoo thiab kev txheeb xyuas kev ncua sijhawm, thiab ntau ntxiv. Cov xwm txheej no yuav tsum paub txhua yam kev teeb tsa thawj zaug ntawm daim iav thiab suav nrog cov uas tsis muaj nyob hauv daim iav thawj zaug nws tus kheej.
Lub ERSPAN Type III composite header muaj xws li 12-byte header uas yuav tsum tau ua thiab 8-byte platform-specific subheader uas xaiv tau.
Cov hom ntawv ERSPAN header rau Hom III yog raws li nram no:
Dua li, tom qab daim iav thawj yog 4-byte CRC.
Raws li pom tau los ntawm hom ntawv header ntawm Hom III, ntxiv rau kev khaws cia Ver, VLAN, COS, T thiab Session ID teb raws li Hom II, ntau qhov chaw tshwj xeeb tau ntxiv, xws li:
• BSO: siv los qhia txog qhov kev thauj khoom ntawm cov ntaub ntawv uas nqa los ntawm ERSPAN. 00 yog ib lub thav duab zoo, 11 yog ib lub thav duab phem, 01 yog ib lub thav duab luv luv, 11 yog ib lub thav duab loj;
• Lub Sijhawm Timestamp: xa tawm los ntawm lub moos kho vajtse uas sib dhos nrog lub sijhawm ntawm lub kaw lus. Daim teb 32-ntsis no txhawb nqa tsawg kawg 100 microseconds ntawm Timestamp granularity;
• Hom Ncej (P) thiab Hom Ncej (FT): tus thawj yog siv los qhia seb ERSPAN puas nqa Ethernet protocol frames (PDU frames), thiab tus tom kawg yog siv los qhia seb ERSPAN puas nqa Ethernet frames lossis IP packets.
• HW ID: tus cim tshwj xeeb ntawm lub cav ERSPAN hauv lub kaw lus;
• Gra (Timestamp Granularity): Qhia txog Granularity ntawm Timestamp. Piv txwv li, 00B sawv cev rau 100 microsecond Granularity, 01B 100 nanosecond Granularity, 10B IEEE 1588 Granularity, thiab 11B xav tau cov sub-headers tshwj xeeb rau platform kom ua tiav Granularity siab dua.
• Platform ID piv rau Platform Specific Info: Cov teb Platform Specific Info muaj cov hom ntawv thiab cov ntsiab lus sib txawv nyob ntawm tus nqi Platf ID.
Yuav tsum nco ntsoov tias ntau yam header teb uas tau txhawb nqa saum toj no tuaj yeem siv rau hauv cov ntawv thov ERSPAN ib txwm muaj, txawm tias mirroring qhov yuam kev thav duab lossis BPDU thav duab, thaum tswj hwm lub pob Trunk qub thiab VLAN ID. Tsis tas li ntawd, cov ntaub ntawv tseem ceeb timestamp thiab lwm cov ntaub ntawv teb tuaj yeem ntxiv rau txhua lub thav duab ERSPAN thaum lub sijhawm mirroring.
Nrog ERSPAN tus kheej cov headers feature, peb tuaj yeem ua tiav kev tshuaj xyuas zoo dua ntawm cov tsheb khiav hauv network, thiab tom qab ntawd tsuas yog mount ACL sib xws hauv ERSPAN cov txheej txheem kom phim cov tsheb khiav hauv network uas peb xav tau.
ERSPAN Siv RDMA Session Visibility
Cia peb siv ib qho piv txwv ntawm kev siv thev naus laus zis ERSPAN los ua kom pom kev sib tham RDMA hauv qhov xwm txheej RDMA:
RDMA: Kev Nkag Mus Rau Lub Cim Xeeb Ncaj Qha ua rau lub network adapter ntawm server A nyeem thiab sau lub Cim Xeeb ntawm server B los ntawm kev siv cov ntawv qhia network interface ntse (inics) thiab cov switches, ua tiav bandwidth siab, latency qis, thiab kev siv cov peev txheej tsawg. Nws yog siv dav hauv cov ntaub ntawv loj thiab cov xwm txheej cia khoom faib tawm siab.
RoCEv2RDMA hla Converged Ethernet Version 2. Cov ntaub ntawv RDMA raug encapsulated hauv UDP Header. Tus lej chaw nres nkoj yog 4791.
Kev ua haujlwm thiab kev saib xyuas txhua hnub ntawm RDMA yuav tsum tau sau ntau cov ntaub ntawv, uas yog siv los sau cov kab ntsuas dej txhua hnub thiab cov tswb ceeb toom tsis zoo, nrog rau lub hauv paus rau kev nrhiav cov teeb meem tsis zoo. Ua ke nrog ERSPAN, cov ntaub ntawv loj heev tuaj yeem ntes tau sai sai kom tau txais cov ntaub ntawv zoo ntawm kev xa mus rau microsecond thiab cov xwm txheej sib cuam tshuam ntawm cov txheej txheem ntawm kev hloov pauv chip. Los ntawm cov ntaub ntawv txheeb cais thiab kev tshuaj xyuas, RDMA qhov kawg-rau-kawg kev xa mus rau qhov kawg kev ntsuas zoo thiab kev kwv yees tuaj yeem tau txais.
Yuav kom ua tiav qhov kev pom ntawm RDAM, peb xav tau ERSPAN los phim cov lus tseem ceeb rau RDMA kev sib tham thaum mirroring traffic, thiab peb yuav tsum siv cov npe kws tshaj lij.
Cov lus txhais ntawm daim ntawv teev npe txuas ntxiv rau cov kws tshaj lij:
UDF muaj tsib daim teb: UDF keyword, base field, offset field, value field, thiab mask field. Vim muaj peev xwm ntawm cov khoom siv kho vajtse, tag nrho yim UDF siv tau. Ib UDF tuaj yeem phim tau ob bytes.
• Lo lus tseem ceeb UDF: UDF1... UDF8 Muaj yim lo lus tseem ceeb ntawm thaj chaw sib phim UDF
• Lub hauv paus teb: qhia qhov chaw pib ntawm lub teb sib phim UDF. Cov hauv qab no
L4_header (siv tau rau RG-S6520-64CQ)
L5_header (rau RG-S6510-48VS8Cq)
• Kev Sib Tshuam: qhia txog kev sib txuas raws li daim teb pib. Tus nqi yog txij li 0 txog 126
• Daim teb nqi: tus nqi sib phim. Nws tuaj yeem siv ua ke nrog daim teb npog los teeb tsa tus nqi tshwj xeeb kom phim. Lub ntsis siv tau yog ob bytes
• Daim teb npog ntsej muag: npog ntsej muag, qhov me me siv tau yog ob bytes
(Ntxiv: Yog tias siv ntau daim ntawv nkag rau hauv tib daim teb UDF sib phim, cov teb puag thiab cov teb offset yuav tsum zoo ib yam.)
Ob lub pob ntawv tseem ceeb uas cuam tshuam nrog RDMA session status yog Congestion Notification Packet (CNP) thiab Negative Acknowledgment (NAK):
Tus thawj yog tsim los ntawm RDMA receiver tom qab tau txais cov lus ECN xa los ntawm qhov hloov (thaum lub eout Buffer mus txog qhov txwv), uas muaj cov ntaub ntawv hais txog qhov ntws lossis QP ua rau muaj kev sib tsoo. Tus tom kawg yog siv los qhia tias RDMA kis tau muaj cov lus teb poob pob.
Cia peb saib seb yuav ua li cas thiaj phim ob tsab xov xwm no siv daim ntawv teev npe txuas ntxiv rau theem kws tshaj lij:
daim ntawv teev cov kws tshaj lij nkag mus rau rdma txuas ntxiv
tso cai udp txhua yam txhua yam txhua yam eq 4791udf 1 l4_header 8 0x8100 0xFF00(Sib phim RG-S6520-64CQ)
tso cai udp txhua yam txhua yam txhua yam eq 4791udf 1 l5_header 0 0x8100 0xFF00(Sib phim RG-S6510-48VS8CQ)
daim ntawv teev cov kws tshaj lij nkag mus rau rdma txuas ntxiv
tso cai udp txhua yam txhua yam txhua yam eq 4791udf 1 l4_header 8 0x1100 0xFF00 udf 2 l4_header 20 0x6000 0xFF00(Sib phim RG-S6520-64CQ)
tso cai udp txhua yam txhua yam txhua yam eq 4791udf 1 l5_header 0 0x1100 0xFF00 udf 2 l5_header 12 0x6000 0xFF00(Sib phim RG-S6510-48VS8CQ)
Ua ib kauj ruam kawg, koj tuaj yeem pom qhov kev sib tham RDMA los ntawm kev teeb tsa daim ntawv teev cov kws tshaj lij txuas ntxiv rau hauv cov txheej txheem ERSPAN tsim nyog.
Sau rau hauv qhov kawg
ERSPAN yog ib qho ntawm cov cuab yeej tseem ceeb hauv cov tes hauj lwm chaw khaws ntaub ntawv loj zuj zus niaj hnub no, kev khiav tsheb hauv network nyuaj zuj zus, thiab kev ua haujlwm thiab kev saib xyuas network uas nyuaj zuj zus.
Nrog rau qib kev ua haujlwm ntawm O&M automation uas nce ntxiv, cov thev naus laus zis xws li Netconf, RESTconf, thiab gRPC nrov ntawm cov tub ntxhais kawm O&M hauv network automatic O&M. Kev siv gRPC ua tus txheej txheem hauv qab rau kev xa rov qab daim iav tsheb kuj muaj ntau qhov zoo. Piv txwv li, raws li HTTP/2 protocol, nws tuaj yeem txhawb nqa lub tshuab streaming push hauv qab tib qhov kev sib txuas. Nrog ProtoBuf encoding, qhov loj ntawm cov ntaub ntawv raug txo los ntawm ib nrab piv rau JSON hom ntawv, ua rau kev xa cov ntaub ntawv sai dua thiab ua haujlwm tau zoo dua. Xav txog, yog tias koj siv ERSPAN los ua daim iav cov kwj dej uas xav tau thiab tom qab ntawd xa lawv mus rau lub server tshuaj xyuas ntawm gRPC, nws puas yuav txhim kho lub peev xwm thiab kev ua haujlwm ntawm network automatic kev ua haujlwm thiab kev saib xyuas?
Lub sijhawm tshaj tawm: Tsib Hlis-10-2022
