CS6250/l CSl 6250l Examl 2l (Latestl 2025/l 2026l Update)l Reviewl Q/Al |l Gradel A|l 100%l Correctl (Verifiedl Answers)
Q:l Whyl wasl OpenFlowl builtl onl existingl hardware?l Whatl wasl thel weaknessl ofl this?
Answer:
Enabledl immediatel deployment Lessl flexibility
Q:l Howl doesl anl openflowl switchl work?
Answer:
Switchl hasl TABLEl OFl PACKETl HANDLINGl RULES eachl rulel hasl al pattern,l listl ofl actions,l setl ofl counters,l andl priority
whenl packetl isl received,l thel switch:
-l determinesl highestl priorityl matchingl rule -l performsl action -l incrementsl counter
Q:l Whatl happensl whenl anl openflowl switchl receivesl al packet?
Answer:
-l determinesl highestl priorityl matchingl rule -l performsl action -l incrementsl counter
Q:l Whichl SDNl techl wasl adoptedl inl thel industry:l activel networks,l control/datal planel separation,l Openflow?
Answer:
Openflowl
Q:l Whatl arel 3l techl developmentsl thatl encouragedl openflow?
Answer: 1 / 4
1.l programmersl couldl controll somel forwardingl behaviorl (b/cl ofl switchl chipsetl vendors) 2.l companiesl couldl buildl switchesl withoutl designingl theirl ownl DATAl PLANE 3.l earlyl versionsl ofl openflowl werel builtl onl techl thatl switchesl ALREADYl SUPPORTED -l justl al firml upgrade
Q:l Werel earlyl versionsl ofl openflowl builtl froml thel groundl up?
Answer:
No,l builtl onl techl thatl switchesl alreadyl supportedl
Q:l Wasl itl difficultl tol integratel openflow?l Why?
Answer:
No,l builtl onl alreadyl supportedl techl
Q:l Whatl werel 3l usel casesl forl openflow?
Answer:
1.l largel scalel experimentsl onl network 2.l managingl trafficl atl largel scalesl inl data-centerl networks 3.l investingl inl programmersl tol writel controll programs,l andl lessl inl proprietaryl switchesl thatl couldn'tl supportl newl features
Q:l Didl openflowl preventl smalll playersl froml beingl competitve?l Why
Answer:
No,l becamel morel competitivel b/cl theyl couldl justl focusl onl writingl controll programsl insteadl ofl proprietaryl switches
Q:l Whatl arel 3l keyl effectsl ofl openflow?
Answer:
1.l GENERALIZATIONl ofl networkl devicesl andl functions 2.l Visionl ofl NETWORKl OPERATINGl SYSTEM 3.l DISTRIBUTEl STATEl MANAGEMENT l techniques
Q:l Whatl doesl thel controll planel do?
Answer:
Logicl thatl controlsl forwardingl behaviorl ofl routersl suchl asl ROUTINGl PROTOCOLSl andl NETWORKl MIDDLEBOXl configurations DICTATESl forwardingl behavior 2 / 4
Q:l Whatl doesl thel datal planel do?
Answer:
PERFORMSl actuall forwardingl asl dictatedl byl controll plane IPl FORWARDINGl andl LAYERl 2l SWITCHING
Q:l Whatl arel 2l reasonsl tol separatel controll andl datal plane?
Answer:
1.l independentl evolutionl andl developmentl ofl bothl planes -l ex.l routingl algorithmsl canl improvel WITHOUTl AFFECTINGl EXISTINGl ROUTERS 2.l Controll froml HIGHl LEVELl softwarel program -l SDNl usesl softwarel tol COMPUTEl forwardingl tablesl -l softwarel tol CONTROLl router'sl behavior -l DEBUGGINGl ISl EASIER
Q:l Whatl arel 4l areasl thel separationl ofl control/datal planel helps?
Answer:
1.l Datal centersl -l networkl managementl isl easier 2.l routing -l SDNl makesl itl easierl tol updatel state -l morel controll overl pathl selection 3.l enterprisel networks -l SDNl improvesl securityl applicationsl -l dropl trafficl atl strategicl locations 4.l researchl networks -l researchl canl coexistl w/l productionl networks
Q:l whatl arel 2l importantl functionsl ofl networkl layer?
Answer:
1.l forwarding -l determinel whichl outputl linkl al packetl shouldl bel sentl tol usingl forwardingl table -l LOCALl functionl implementedl inl HARDWARE -l datal plane -l nanoseconds 2.l determinesl pathl froml senderl tol receiverl acrossl thel networkl (usuallyl withl routingl algorithms) -l e2el processl forl networks -l seconds 3 / 4
-l controll planel
Q:l howl longl doesl forwardingl takel vs.l routing?
Answer:
-l nanoseconds -l secondsl (longer)
Q:l Whatl planel isl forwardingl on?l routing?
Answer:
-l datal plane -l controll plane
Q:l isl forwardingl inl softwarel orl hardware?l routing?
Answer:
-l hardware -l software
Q:l Whatl isl traditionall approachl ofl routingl algorithmsl andl forwardingl function?l SDNl approach?
Answer:
traditionall approach -l closelyl coupled -l routerl runsl routingl algsl thenl constructsl forwardingl tablel andl consults SDNl approach -l routersl arel SOLELYl responsiblel forl forwardingl packetsl -l remotel controllerl distributesl forwardingl tablesl forl EVERYl ROUTERl andl isl implementedl inl thel SOFTWARE -l PHYSICALLYl SEPARATE -l remotel controllerl implementationl isl openl andl publiclyl available
Q:l Withl SDN,l whatl isl responsiblel forl forwarding?l Whatl isl responsiblel forl computingl andl distributingl forwardingl tables?
Answer:
-l ROUTER -l Remotel controller
Q:l Withl SDN,l dol routersl andl remotel controllerl havel tol bel inl thel samel location?
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