思科认证考试
Which three options are considered in the spanning-tree decision process？（）A、lowest root bridge IDB、lowest path cost to root bridgeC、lowest sender bridge IDD、highest port IDE、highest root bridge IDF、highest path cost to root bridge
题目
Which three options are considered in the spanning-tree decision process？（）
- 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
相似问题和答案
第1题：
A. the switch with the lowest MAC address
B. the switch with the higest MAC address
C. the switch witch the higest IP address
D. the switch with the lowest IP address
第2题：
A.Switch A ,because it has the lowest MAC address
B.Switch C,because it has the lowest priority
C.Switch B,because it has the highest MAC address
D.Switch C,because it is the most centrally located switch
E.Switch A,because it is the most centrally located switch
F.Switch D,because it has the highest priority
第3题：
What value is primarily used to determine which port becomes the root port on each nonroot switch in a spanning-tree topology?
A. path cost
B. lowest port MAC address
C. VTP revision number
D. highest port priority number
E. port priority number and MAC address
F. None of the above
A 解析：Explanation:
At the conclusion of the root bridge election process, the switches move on to selecting Root Ports. The Root Port of a bridge is the port that is closest to the Root Bridge in terms of Path Cost.
Every non-Root Bridge must select one Root Port. Again, bridges use the concept of cost to measure closeness. As with some routing metrics, the measure of closeness using STP is not necessarily reflected by hop count. Specifically, bridges track what is referred to as Root Path Cost, which is the cumulative cost of all links to the Root Bridge.
第4题：
The classic Spanning Tree Protocol （802.1 D 1998） uses which sequence of variables to determine thebest received BPDU？（）
- 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） lowest sender port id
- D、1） lowest root bridge id，2） lowest root path cost，3） lowest sender bridge id，4） lowest sender port id
正确答案:D
第5题：
In the Cisco FabricPath domain， one switch becomes the root for the multidestination tree. Cisco FabricPath switches compare which three parameters to select the root？ （）
- A、 Root priority
- B、 System ID
- C、 Bridge ID
- D、 Switch ID
- E、 Port ID
- F、 Subswitch ID
正确答案:A,B,D
第6题：
The network administrator has discovered that the power supply has failed on a switch in the company LAN and that the switch has stopped functioning. It has been replaced with a Cisco Catalyst 2950 series switch. What must be done to ensure that this new switch becomes the root bridge on the network?（）
A. Lower the bridge priority number.
B. Change the MAC address of the switch.
C. Increase the VTP revision number for the domain.
D. Lower the root path cost on the switch ports.
E. Assign the switch an IP address with the lowest value.
第7题：
生成树的比较过程中，表明根的字段是（）.
- A、root id
- B、cost
- C、bridge id
- D、port id
正确答案:A
第8题：
Which two of the following values does STP take into consideration when it elects the root bridge? (Select two answer choices)
A. The BPDU version number
B. The access layer bridge setting
C. The Bridge ID
D. The spanning-tree update number
E. The bridge priority
F. The VLAN number
C,E 解析：Explanation:
The bridges elect a root bridge based on the bridge IDs in the BPDUs. The root bridge is the bridge with the lowest numeric value for the bridge ID. Because the two part bridge ID starts with the priority value, essentially the bridge with the lowest priority becomes the root.
For instance, if one bridge has priority 100, and another bridge has priority 200, the bridge with priority 100 wins, regardless of what MAC address was used to create the bridge ID or each bridge/switch.
第9题：
What value is primarily used to determine which port becomes the root port on each nonroot switch in a spanning-tree topology？（）
- A、lowest port MAC address
- B、port priority number and MAC address
- C、VTP revision number
- D、highest port priority number
- E、path cost
正确答案:E
第10题：
The classic Spanning Tree Protocol （802.1D 1998） uses which sequence of variables to determine the best received BPDU？（）
- 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
正确答案:D