panning Tree Protocol calculates path cost based on which of these？（）

A . Combine all the VLAN spanning trees into a single spanning tree B . Set forward delay and max-age timers to the maximum possible values C . None of the choices D . Change the router VTP server mode E . Disable the root bridge

A . one global STP instance for all VLANs B . one STP instance for each VLAN C . one STP instance per set of VLANs D . one STP instance per set of bridge

A . designated ports. B . duplex operating mode. C . fast mode ports. D . root bridge. E . root ports. F . BDPU priority.

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

A . Layer 5 B . Layer 4 C . Layer 3 D . Layer 2 E . Layer 1

A . Designated Root Cost B . bridge ID priority C . max age D . bridge ID MAC address E . Designated Root Priority F . forward delay

A .  1） lowest root bridge id，2）lowest sender bridge id，3）lowest port id，4）lowest root path cost B .  1） lowest root path cost，2）lowest root bridge id，3）lowest sender bridge id，4）lowest sender port id C .  1） lowest root bridge id，2）lowest sender bridge id，3）lowest root path cost 4）owest sender port id D .  1） lowest root bridge id，2）lowest root path cost，3）lowest sender bridge id，4）lowest sender port id

A . to ensure a loop-free topology B . to protect against user-side loops C . when a VLAN spans access layer switches D . for the most deterministic and highly available network topology E . because of the risk of lost connectivity without Spanning Tree Protocol

A . PortFast B . UplinkFast C . loop guard D . root guard E . BPDU guard F . BackboneFast

A . one global STP instance for all VLANs B . one STP instance for each VLAN C . one STP instance per set of VLANs D . one STP instance per set of bridge

A . lowest root bridge id；lowest sender bridge id；lowest port id；lowest root path cost B . lowest root path cost；lowest root bridge id；lowest sender bridge id；lowest sender port id C . lowest root bridge id；lowest sender bridge id；lowest root path cost；lowest sender port id D . lowest root bridge id；lowest root path cost；lowest sender bridge id；lowest sender port id

A .  To verify the MST configuration， the show pending command can be used in MST configuration  mode. B .  When RSTP and MSTP are configured； UplinkFast and BackboneFast must also be enabled. C .  All switches in the same MST region must have the same VLAN-to-instance mapping， but  different configuration revision numbers. D .  All switches in an MST region， except distribution layer switches， should have their priority  lowered from the default value 32768. E .  An MST region is a group of MST switches that appear as a single virtual bridge to adjacent  CST and MST regions. F .  Enabling MST with the "spanning-tree modemst" global configuration command also enables  RSTP.

A . amount of RAM B . bridge priority C . IOS version D . IP address E . MAC address F . speed of the link

A .  Designated Root Cost B .  bridge ID priority C .  max age D .  bridge ID MAC address E .  Designated Root Priority F .  forward delay

A . amount of RAM B . bridge priority C . IOS version D . IP address E . MAC address F . speed of the link

A .  Spanning tree protect B .  Root Guard and BPDU Guard C .  Unicast Reverse Path Forwarding D .  MAC spoof guard E .  Port Security

A .  PortFast B .  UplinkFast C .  loop guard D .  root guard E .  BPDU guard F .  BackboneFast

A . root port B . backup port C . designated port D . alternate port

A .  To enhance Spanning Tree troubleshooting on multilayer switches B .  To reduce the total number of spanning tree instances necessary for a particular topology  C .  To provide faster convergence when topology changes occur in a switched network D .  To provide protection for STP when a link is unidirectional and BPDUs are being sent but not  received E .  None of the other alternatives apply

A .  to ensure a loop-free topology B .  to protect against user-side loops C .  when a VLAN spans access layer switches D .  for the most deterministic and highly available network topology E .  because of the risk of lost connectivity without Spanning Tree Protocol

A . 避免交换网络中存在的环路，防止交换网络风暴 B . 提高核心交换网络的传输性能 C . 提高核心广域网络的传输性能 D . 提高核心广域网的冗余性

A .  one global STP instance for all VLANs B .  one STP instance for each VLAN C .  one STP instance per set of VLANs D .  one STP instance per set of bridge

A . amount of RAM B . bridge priority C . IOS version D . IP address E . MAC address F . speed of the link