Cov cuab yeej siv tshaj plaws rau kev saib xyuas thiab kev daws teeb meem niaj hnub no yog Hloov Chaw Tshawb Fawb (SPAN), tseem hu ua Port mirroring. Nws tso cai rau peb saib xyuas kev sib txuas hauv network hauv bypass tawm ntawm hom band yam tsis muaj kev cuam tshuam nrog cov kev pabcuam hauv lub network nyob, thiab xa ib daim qauv ntawm kev saib xyuas kev khiav mus rau cov khoom siv hauv zos lossis cov chaw taws teeb, suav nrog Sniffer, IDS, lossis lwm hom kev txheeb xyuas network.
Qee qhov kev siv feem ntau yog:
• Teeb meem teeb meem hauv network los ntawm kev taug qab tswj / cov ntaub ntawv thav ntawv;
• Txheeb xyuas latency thiab jitters los ntawm kev saib xyuas cov pob ntawv VoIP;
• Tshawb xyuas latency los ntawm kev saib xyuas kev sib tham hauv network;
• Tshawb xyuas qhov tsis txaus ntseeg los ntawm kev saib xyuas cov tsheb khiav hauv lub network.
SPAN Tsheb tuaj yeem nyob hauv ib cheeb tsam mirrored rau lwm qhov chaw nres nkoj ntawm tib lub hauv paus khoom, lossis remotely mirrored rau lwm lub network li uas nyob ib sab rau Txheej 2 ntawm qhov chaw ntaus ntawv (RSPAN).
Niaj hnub no peb yuav los tham txog Cov Chaw Taws Teeb Hluav Taws Xob Hluav Taws Xob Hluav Taws Xob Hluav Taws Xob Hluav Taws Xob Hluav Taws Xob hu ua ERSPAN (Encapsulated Remote Switch Port Analyzer) uas tuaj yeem kis tau los ntawm peb txheej IP. Qhov no yog qhov txuas ntxiv ntawm SPAN rau Encapsulated Chaw Taws Teeb.
Cov hauv paus ntsiab lus ua haujlwm ntawm ERSPAN
Ua ntej, cia peb saib ntawm ERSPAN cov yam ntxwv:
• Ib daim ntawv theej ntawm pob ntawv los ntawm qhov chaw nres nkoj xa mus rau qhov chaw neeg rau zaub mov rau kev txheeb xyuas los ntawm Generic Routing Encapsulation (GRE). Lub cev qhov chaw ntawm lub server tsis txwv.
• Nrog kev pab los ntawm Tus Neeg Siv Lub Chaw Ua Haujlwm (UDF) feature ntawm lub nti, ib qho offset ntawm 1 mus rau 126 bytes yog ua raws li Base domain los ntawm cov kws tshaj lij-qib cov npe txuas ntxiv, thiab cov ntsiab lus sib tham tau sib tw kom paub txog kev pom. ntawm kev sib tham, xws li TCP peb-txoj kev tuav tes thiab RDMA kev sib ntsib;
• Txhawb kev teeb tsa tus nqi piv txwv;
• Txhawb pob ntawv cuam tshuam ntev (Packet Slicing), txo qhov siab ntawm lub hom phiaj server.
Nrog rau cov yam ntxwv no, koj tuaj yeem pom yog vim li cas ERSPAN yog ib qho tseem ceeb rau kev saib xyuas cov tes hauj lwm hauv cov chaw zov me nyuam niaj hnub no.
ERSPAN lub luag haujlwm tseem ceeb tuaj yeem muab sau ua ob yam:
• Session Visibility: Siv ERSPAN los sau tag nrho cov tsim tshiab TCP thiab Remote Direct Memory Access (RDMA) zaug rau cov neeg rau zaub mov tom qab rau zaub;
• Kev daws teeb meem hauv network: ntes cov tsheb khiav hauv lub network rau kev soj ntsuam yuam kev thaum muaj teeb meem hauv network.
Ua li no, lub hauv paus network ntaus ntawv yuav tsum tau lim tawm cov tsheb khiav ntawm kev txaus siab rau cov neeg siv los ntawm cov ntaub ntawv loj heev, ua ib daim ntawv luam, thiab encapsulate txhua daim ntawv thav duab rau hauv ib qho tshwj xeeb "superframe container" uas nqa cov ntaub ntawv ntxiv kom txaus. yuav raug xa mus rau lub cuab yeej txais. Ntxiv mus, pab kom tau txais cov cuab yeej kom rho tawm thiab rov ua tiav cov thawj tswj xyuas tsheb.
Cov khoom tau txais tuaj yeem yog lwm tus neeg rau zaub mov uas txhawb nqa decapsulating ERSPAN pob ntawv.
ERSPAN Hom thiab Pob Hom Kev Ntsuam Xyuas
ERSPAN pob ntawv tau encapsulated siv GRE thiab xa mus rau txhua tus IP chaw nyob ntawm Ethernet. ERSPAN tam sim no tsuas yog siv rau hauv IPv4 tes hauj lwm, thiab kev txhawb nqa IPv6 yuav yog qhov yuav tsum tau ua yav tom ntej.
Rau cov qauv encapsulation dav dav ntawm ERSAPN, cov hauv qab no yog daim iav ntim ntim ntawm ICMP pob ntawv:
ERSPAN raws tu qauv tau tsim nyob rau hauv lub sij hawm ntev, thiab nrog rau kev txhim kho ntawm nws cov peev xwm, ob peb versions tau tsim, hu ua "ERSPAN Hom". Cov hom sib txawv muaj cov kab ntawv sib txawv header hom.
Nws tau txhais nyob rau hauv thawj Version teb ntawm ERSPAN header:
Tsis tas li ntawd, raws tu qauv hom teb nyob rau hauv GRE header kuj qhia lub sab hauv ERSPAN hom. Tus Txheej Txheem Hom teb 0x88BE qhia ERSPAN Hom II, thiab 0x22EB qhia ERSPAN Hom III.
1. Hom I
Lub ERSPAN thav duab ntawm Hom Kuv encapsulates IP thiab GRE ncaj qha hla lub header ntawm thawj daim iav ncej. Qhov no encapsulation ntxiv 38 bytes hla tus ncej qub: 14 (MAC) + 20 (IP) + 4 (GRE). Qhov zoo ntawm hom ntawv no yog tias nws muaj qhov loj me me thiab txo tus nqi ntawm kev sib kis. Txawm li cas los xij, vim tias nws teeb tsa GRE Chij thiab Version teb rau 0, nws tsis nqa cov teb txuas ntxiv thiab Hom Kuv tsis siv dav, yog li tsis tas yuav nthuav dav ntxiv.
GRE header hom ntawm Hom I yog raws li hauv qab no:
2. Hom II
Hauv Hom II, C, R, K, S, S, Recur, Chij, thiab Version teb hauv GRE header yog tag nrho 0 tsuas yog S field. Yog li ntawd, qhov Sequence Number teb tau tshwm sim hauv GRE header ntawm Hom II. Ntawd yog, Hom II tuaj yeem ua kom ntseeg tau tias qhov kev txiav txim tau txais GRE pob ntawv, yog li ntawd ntau cov pob ntawv GRE tsis tuaj yeem raug txheeb xyuas vim yog lub network txhaum.
GRE header hom ntawv hom II yog raws li nram no:
Tsis tas li ntawd, ERSPAN Hom II thav duab hom ntxiv 8-byte ERSPAN header ntawm GRE header thiab tus thawj mirrored ncej.
ERSPAN header hom ntawv rau Hom II yog raws li nram no:
Thaum kawg, tam sim ntawd ua raws li cov duab qub, yog tus qauv 4-byte Ethernet cyclic redundancy check (CRC) code.
Nws yog ib nqi sau cia hais tias nyob rau hauv qhov kev siv, daim iav thav duab tsis muaj FCS teb ntawm tus thawj thav duab, es tsis txhob tus tshiab CRC tus nqi yog xam raws li tag nrho cov ERSPAN. Qhov no txhais tau hais tias cov cuab yeej txais tsis tuaj yeem txheeb xyuas qhov tseeb ntawm CRC ntawm tus ncej qub, thiab peb tsuas tuaj yeem xav tias tsuas yog cov thav ntawv tsis raug cuam tshuam yog tsom iav.
3. Type III
Hom III qhia txog qhov loj dua thiab hloov pauv tau yooj yim dua los hais txog qhov nyuaj thiab sib txawv ntawm kev saib xyuas lub network, suav nrog tab sis tsis txwv rau kev tswj hwm network, kev nkag mus rau kev tshawb nrhiav, kev ua haujlwm thiab kev soj ntsuam qeeb, thiab lwm yam. Cov scenes no yuav tsum paub tag nrho cov tseem ceeb ntawm daim iav thav duab thiab suav nrog cov uas tsis muaj nyob rau hauv thawj thav duab nws tus kheej.
ERSPAN Type III composite header suav nrog qhov yuav tsum tau ua 12-byte header thiab ib qho kev xaiv 8-byte platform-specific subheader.
ERSPAN header hom rau Hom III yog raws li nram no:
Ib zaug ntxiv, tom qab thawj daim iav ncej yog 4-byte CRC.
Raws li tuaj yeem pom los ntawm hom ntawv header ntawm Hom III, ntxiv rau khaws cov Ver, VLAN, COS, T thiab Session ID teb raws li hom II, ntau qhov tshwj xeeb tau ntxiv, xws li:
• BSO: siv los qhia txog kev ncaj ncees ntawm cov ntaub ntawv thav ntawv nqa los ntawm ERSPAN. 00 yog ib tug zoo ncej, 11 yog ib tug phem ncej, 01 yog ib tug luv ncej, 11 yog ib tug loj ncej;
• Timestamp: xa tawm los ntawm lub moos kho vajtse synchronized nrog lub sijhawm ua haujlwm. Qhov no 32-ntsis teb txhawb tsawg kawg yog 100 microseconds ntawm Timestamp granularity;
• Ncej Hom (P) thiab Ncej Hom (FT): tus qub yog siv los qhia seb ERSPAN nqa Ethernet raws tu qauv thav duab (PDU ntas), thiab tom kawg yog siv los qhia seb ERSPAN nqa Ethernet thav ntawv lossis IP pob ntawv.
• HW ID: tus cim tshwj xeeb ntawm lub cav ERSPAN hauv lub cev;
• Gra (Timestamp Granularity) : Qhia meej txog qhov Granularity ntawm Timestamp. Piv txwv li, 00B sawv cev rau 100 microsecond Granularity, 01B 100 nanosecond Granularity, 10B IEEE 1588 Granularity, thiab 11B yuav tsum muaj platform-specific sub-headers kom ua tiav siab dua Granularity.
• Platf ID vs. Platform Specific Info: Platf Specific Info fields muaj ntau hom thiab cov ntsiab lus nyob ntawm tus nqi Platf ID.
Nws yuav tsum tau muab sau tseg tias ntau yam header teb kev txhawb nqa saum toj no tuaj yeem siv rau hauv ERSPAN daim ntawv thov tsis tu ncua, txawm tias mirroring yuam kev thav duab los yog BPDU thav ntawv, thaum tuav cov pob pob tw thawj thiab VLAN ID. Tsis tas li ntawd, cov ntaub ntawv teev sijhawm tseem ceeb thiab lwm cov ntaub ntawv tuaj yeem muab ntxiv rau txhua ERSPAN thav duab thaum tsom iav.
Nrog ERSPAN tus kheej cov ntsiab lus headers, peb tuaj yeem ua tiav qhov kev soj ntsuam zoo dua ntawm kev sib txuas hauv network, thiab tom qab ntawd tsuas yog mount qhov sib thooj ACL hauv ERSPAN txheej txheem kom phim cov tsheb khiav hauv network uas peb xav tau.
ERSPAN Implements RDMA Session Visibility
Cia peb ua piv txwv ntawm kev siv ERSPAN thev naus laus zis kom ua tiav RDMA kev sib ntsib pom hauv RDMA qhov xwm txheej:
RDMA: Tej thaj chaw deb Direct Memory Access ua rau lub network adapter ntawm server A los nyeem thiab sau lub cim xeeb ntawm server B los ntawm kev siv cov ntse network interface phaib (inics) thiab cov keyboards, ua tiav cov bandwidth siab, tsis tshua muaj latency, thiab kev siv cov peev txheej tsawg. Nws yog siv dav hauv cov ntaub ntawv loj thiab kev ua haujlwm siab faib cov xwm txheej.
RoCEv 2: RDMA dhau Converged Ethernet Version 2. Cov ntaub ntawv RDMA yog encapsulated hauv UDP Header. Qhov chaw nres nkoj tus naj npawb yog 4791.
Kev ua haujlwm txhua hnub thiab kev saib xyuas ntawm RDMA yuav tsum tau sau ntau cov ntaub ntawv, uas yog siv los sau cov kab ntawv qhia dej txhua hnub thiab lub tswb tsis zoo, nrog rau lub hauv paus rau kev nrhiav cov teeb meem txawv txav. Ua ke nrog ERSPAN, cov ntaub ntawv loj tuaj yeem ntes tau sai sai kom tau txais microsecond xa cov ntaub ntawv zoo thiab cov txheej txheem kev sib cuam tshuam ntawm kev hloov nti. Los ntawm cov ntaub ntawv txheeb cais thiab kev tshuaj xyuas, RDMA qhov kawg-rau-kawg xa mus rau qhov kev soj ntsuam zoo thiab kev kwv yees tuaj yeem tau txais.
Txhawm rau ua tiav RDAM kev pom pom, peb xav tau ERSPAN kom phim cov ntsiab lus rau RDMA kev sib tham sib tham thaum tsom iav tsheb, thiab peb yuav tsum siv cov kws tshaj lij txuas ntxiv.
Cov kws tshaj lij-qib ncua cov npe sib piv cov lus txhais:
UDF muaj tsib lub teb: UDF lo lus tseem ceeb, lub hauv paus teb, offset teb, tus nqi teb, thiab daim npog qhov ncauj. Kev txwv los ntawm lub peev xwm ntawm cov khoom siv nkag, tag nrho ntawm yim UDF tuaj yeem siv tau. Ib UDF tuaj yeem phim qhov siab tshaj plaws ntawm ob bytes.
• UDF lo lus tseem ceeb: UDF1... UDF8 Muaj yim lo lus tseem ceeb ntawm UDF qhov sib piv cov npe
• Base teb: txheeb xyuas qhov chaw pib ntawm UDF qhov chaw sib txuam. Hauv qab no
L4_header (muaj feem xyuam rau RG-S6520-64CQ)
L5_header (rau RG-S6510-48VS8Cq)
• Offset: qhia qhov offset raws li lub hauv paus teb. Tus nqi yog li ntawm 0 txog 126
• Tus nqi teb: sib piv tus nqi. Nws tuaj yeem siv ua ke nrog daim npog ntsej muag kom teeb tsa tus nqi tshwj xeeb kom phim. Qhov siv tau me ntsis yog ob bytes
• Mask teb: daim npog qhov ncauj, siv tau me ntsis yog ob bytes
(Ntxiv: Yog tias muaj ntau qhov kev nkag tau siv hauv tib qhov UDF qhov sib txuam, cov hauv paus thiab qhov chaw offset yuav tsum yog tib yam.)
Ob lub pob ntawv tseem ceeb cuam tshuam nrog RDMA qhov xwm txheej yog Congestion Notification Packet (CNP) thiab Kev lees paub tsis zoo (NAK):
Tus qub yog tsim los ntawm RDMA receiver tom qab tau txais cov lus ECN xa los ntawm qhov hloov pauv (thaum lub eout Buffer ncav cuag qhov pib), uas muaj cov ntaub ntawv hais txog qhov ntws los yog QP ua rau muaj kev sib tsoo. Cov yav tas yog siv los qhia txog RDMA kis tau tus mob muaj ib pob ntawv poob lus teb.
Cia peb saib yuav ua li cas kom phim ob cov lus no siv cov kws tshaj lij-qib cov npe txuas ntxiv:
tus kws tshaj lij nkag-daim ntawv txuas ntxiv rdma
tso cai udp ib qho twg eq 4791udf 1 l4_header 8 0x8100 0xFF00(Matching RG-S6520-64CQ)
tso cai udp ib qho twg eq 4791udf 1 l5_header 0 0x8100 0xFF00(Matching RG-S6510-48VS8CQ)
tus kws tshaj lij nkag-daim ntawv txuas ntxiv rdma
tso cai udp ib qho twg eq 4791udf 1 l4_header 8 0x1100 0xFF00 udf 2 l4_header 20 0x6000 0xFF00(Matching RG-S6520-64CQ)
tso cai udp ib qho twg eq 4791udf 1 l5_header 0 0x1100 0xFF00 udf 2 l5_header 12 0x6000 0xFF00(Matching RG-S6510-48VS8CQ)
Raws li cov kauj ruam kawg, koj tuaj yeem pom qhov kev sib tham RDMA los ntawm kev teeb tsa cov kws tshaj lij txuas ntxiv rau hauv cov txheej txheem ERSPAN tsim nyog.
Sau ntawv kawg
ERSPAN yog ib qho ntawm cov cuab yeej tseem ceeb hauv niaj hnub no cov ntaub ntawv xov xwm loj zuj zus tuaj, kev sib txuas ua ke ntau zuj zus, thiab kev ua haujlwm zoo hauv network thiab kev saib xyuas.
Nrog kev nce qib ntawm O&M automation, thev naus laus zis xws li Netconf, RESTconf, thiab gRPC yog cov neeg nyiam ntawm O&M cov tub ntxhais kawm hauv network tsis siv neeg O&M. Siv gRPC raws li cov txheej txheem hauv qab rau xa rov qab daim iav tsheb kuj muaj ntau yam zoo. Piv txwv li, raws li HTTP / 2 raws tu qauv, nws tuaj yeem txhawb nqa streaming push mechanism nyob rau hauv tib txoj kev sib txuas. Nrog ProtoBuf encoding, qhov loj ntawm cov ntaub ntawv raug txo los ntawm ib nrab piv rau JSON hom, ua kom cov ntaub ntawv xa mus sai thiab zoo dua. Cia li xav txog tej yam, yog tias koj siv ERSPAN los tsom iav nyiam cov kwj thiab tom qab ntawd xa lawv mus rau qhov kev tshuaj ntsuam xyuas ntawm gRPC, nws puas yuav txhim kho lub peev xwm thiab kev ua tau zoo ntawm kev siv network tsis siv neeg thiab kev saib xyuas?
Post lub sij hawm: May-10-2022
