A.On OnB.On AutoC.Passive ActiveD.Desirable AutoE.Activ……

单项选择题In802.1s，howistheVLANtoinstancemappingrepresentedintheBPDU？（）

A.The VLAN to instance mapping is a normal 16-byte field in the MST BPDU.
B.The VLAN to instance mapping is a normal 12-byte field in the MST BPDU.
C.The VLAN to instance mapping is a 16-byte MD5 signature field in the MST BPDU.
D.The VLAN to instance mapping is a 12-byte MD5 signature field in the MST BPDU.

多项选择题Whichthreeoptionsareconsideredinthespanning-treedecisionprocess？（）

A.lowest root bridge ID
B.lowest path cost to root bridge
C.lowest sender bridge ID
D.highest port ID
E.highest root bridge ID
F.highest path cost to root bridge

多项选择题WhichthreeoptionsarefeaturesofVTPversion3？（）

A.VTPv3 supports 8K VLANs.
B.VTPv3 supports private VLAN mapping.
C.VTPv3 allows for domain discovery.
D.VTPv3 uses a primary server concept to avoid configuration revision issues.
E.VTPv3 is not compatible with VTPv1 or VTPv2.
F.VTPv3 has a hidden password option.

单项选择题SpanningTreeProtocolcalculatespathcostbasedonwhichofthese？（）

A. interface bandwidth
B. interface delay
C. interface bandwidth and delay
D. hop count
E. bridge priority

多项选择题LoopguardandUniDirectionalLinkDetectionbothprotectagainstLayer2STPloops.InwhichtwowaysdoesloopguarddifferfromUDLDinloopdetectionandprevention？（）

A. Loop guard can be used with root guard simultaneously on the same port on the same VLAN while UDLD cannot
B. UDLD protects against STP failures caused by cabling problems that create one-way links.
C. Loop guard detects and protects against duplicate packets being received and transmitted on different ports
D. UDLD protects against unidirectional cabling problems on copper and fiber media.
E. Loop guard protects against STP failures caused by problems that result in the loss of BPDUs from a designated switch port.