在设计实时操作系统中，首先要考虑的是（)。A．灵活性和可靠性B．实时性和可靠性C．交互性和实时性D．资

A. It designates VLAN 999 for untagged traffic.

B. It blocks VLAN 999 traffic from passing on the trunk.

C. It creates a VLAN 999 interface.

D. It designates VLAN 999 as the default for all unkown tagged traffic.

A.thetimeittakesforaLayer3switchoraroutertoswitchapacketfromaninboundinterfacetothequeueoftheoutboundinterface

B.thetimeittakesforapropagatefromsourcetodestination

C.thetimeittakestoplaceaframeonthephysicalmediumfortransport

D.thetimeapacketresidesintheoutboundqueueofarouter

A.Thereisafullmeshofpseudowires.

B.Thereisapartialmeshofpseudowires.

C.OnlyL2TPv3canbeusedforpseudowireestablishment.

D.Thereissplit-horizontoavoidloops.

A. AH

B. MD5

C. PSK

D. ESP

A.delaysensitivepacketsaregivenpreferentialtreatment

B.thedefaultpolicyidentifiesadelaysensitiveclassanddefaultclass

C.thedefaultpolicyidentifiesadelaysensitiveclass，besteffortclass，anddefaultclass

D.themodelishighlyscalable

E.themodelisstillpredominantontheinternetFthemodelprovidesguaranteedservice

A.AllowaCSStoprobetheserver

B.AllowaconnectiontobeclosedwithaTCPRESET

C.Allowpersistentconnections

D.AllowtheuseofHTTPHEADrequest

A.CACisimplementedinthecallsetupphasetoallocatebandwidthresources

B.CACisimplementedinthecallmaintenancephasetoallocatebandwidthresources

C.CACisutilizedduringthecallteardownphasetoensurethatallresourceshavebeenreleased

D.CACusestheCiscoRSVP（ResourceReservationProtocol）Agenttointegratecall-processingcapabilitieswiththeunderlyingnetworkinfrastructure

E.CACisimplementedinthecallsetupphasetodeterminethedestinationofthecall

A.AdditionorDeletionofPVC

B.PVCstatus（activeorinactive）

C.Linkintegrity

D.Noneoftheotheralternativesapply

A. ipv6 address PREFIX_1::1/64

B. ipv6 autoconfig 2001:db8:2222:7272::72/64

C. ipv6 autoconfig

D. ipv6 address 2001:db8:2222:7272::72/64

A.ItprovidescomprehensiveDomainNamesystem

B.ItprovidesDHCPadministrativefunctionality

C.ItprovidesTFTPserverfunctionality.

D.Alloftheabovearetrue