Refer to the exhibit. Based on the information given. Which switch will be elected root bridge and why?()A.Switch A ,because it has the lowest MAC addressB.Switch C,because it has the lowest priorityC.Switch B,because it has the highest MAC addressD.Switc

第1题：

第2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

第3题：

Refer to Topic TestKing.com in iPAD document.Which switch is the root bridge for VLAN 1?（）

• A、TestKingD
• B、TestKing1
• C、TestKing2
• D、TestKing3

第4题：

Refer to the exibit. Three cisco 2950 switches are set to their default priority sttings.During the spanningtree process,which switch will be elected as the root bridge?（）

• A、Switch3
• B、Switch4
• C、Switch2
• D、Switch1

第5题：

Which three statements about STP timers are true？（）

• A、STP timers values （hello， forward delay， max age） are included in each BPDU.
• B、A switch is not concerned about its local configuration of the STP timers values. It will only consider the value of the STP timers contained in the BPDU it is receiving.
• C、To successfully exchange BPDUs between two switches， their STP timers value （hello， forward delay， max age） must be the same.
• D、If any STP timer value （hello， forward delay， max age） needs to be changed， it should at least be changed on the root bridge and backup root bridge.
• E、On a switched network with a small network diameter， the STP hello timer can be tuned to a lower value to decrease the load on the switch CPU.
• F、The root bridge passes the timer information in BPDUs to all routers in the Layer 3 configuration.

第6题：

A network administrator needs to force a high-performance switch that is located in the MDF to become the root bridge for a redundant path switched network. What can be done to ensure that this switch assumes the role as root bridge（）。

• A、Establish a direct link from the switch to all other switches in the network.
• B、Assign the switch a higher MAC address than the other switches in the network have.
• C、Configure the switch so that it has a lower priority than other switches in the network.
• D、Configure the switch for full-duplex operation and configure the other switches for half-duplex operation.
• E、Connect the switch directly to the MDF router, which will force the switch to assume the role of root bridge.

第7题：

Which statement is correct about RSTP port roles？（）

• A、The designated port is the switch port on every nonroot bridge that is the chosen path to theroot bridge. There can be only one designated port on every switch. The designated portassumes the forwarding state in a stable active topology. All switches connected to a given segment listen to all BPDUs and determine the switch that will be the root switch for a particular segment.
• B、The disabled port is an additional switch port on the designated switch with a redundant link to the segment for which the switch is designated. A disabled port has a higher port ID than the disabled port on the designated switch. The disabled port assumes the discarding state in astable active topology.
• C、The backup port is a switch port that offers an alternate path toward the root bridge. The backup port assumes a discarding state in a stable， active topology. The backup port will be present on nondesignated switches and will make a transition to a designated port if the current designated path fails.
• D、The root port is the switch port on every nonroot bridge that is the chosen path to the root bridge. There can be only one root port on every switch. The root port assumes the forwarding state in a stable active topology.

第8题：

Refer to the output shown on switch SW1 below：  VLAN 1 bridge priority set to 8192. VLAN 1 bridge max aging time set to 20.VLAN 1 bridge hello time set to 2. VLAN 1 bridge forward delay set to 15. Switch is now the root switch for active VLAN 1.  What command would you enter to reproduce this output？

第9题：

第10题：

第11题：

第12题：

第13题：

第14题：

Which statement is true about TCN propagation？（）

• A、The originator of the TCN immediately floods this information through the network.
• B、The TCN propagation is a two step process.
• C、A TCN is generated and sent to the root bridge.
• D、The root bridge must flood this information throughout the network.

第15题：

Refer to the exhibit. The output that is shown is generated at a switch. Which three of these statements are true? （）

• A、All ports will be in a state of discarding, learning, or forwarding.
• B、Thirty VLANs have been configured on this switch.
• C、The bridge priority is lower than the default value for spanning tree.
• D、All interfaces that are shown are on shared media.
• E、All designated ports are in a forwarding state.
• F、The switch must be the root bridge for all VLANs on this switch.

第16题：

Which three statements accurately describe layer 2 Ethernet switches?（）

• A、Microsegmentation decreases the number of collisions on the network.
• B、if a switch receives a frame for an unkown destination,it uses ARP to resolve the address.
• C、Spanning Tree Protocol allows switches to automatically share vlan information.
• D、In a properly functioning network with redundant switched paths,each switched aegment will contain one root bridge with all its ports in the forwarding state.All other switches in that broadcast domain will have only one root port.
• E、Establishing vlans increases the number of broadcast domains.
• F、Switches that are configured with vlans make forwarding decisions based on both layer 2 and layer 3 address information.

第17题：

Which of the following components must be elected before the Spanning Tree Protocol can converge in a switched LAN?（）

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

第18题：

As a network administrator， can you tell me what the root guard feature provides in a bridgednetwork？（）

• A、It ensures that BPDUs sent by the root bridge are forwarded in a timely manner
• B、It enforces the root bridge placement in the network
• C、It ensures that all ports receiving BPDUs from the root bridge are in the forwarding state.
• D、It ensures that the bridge is elected as root bridge in the network.

第19题：

Three switches are connected to one anther via trunk ports.Assuming the default switch configuration,which switch is elected as the root bridge for the spanning-tree instance of vlan 1?（）

• 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20题：

第21题：

第22题：

第23题：