思科认证考试
The following was configured on a switch： Switch（config） # spanning-tree portfast bpdufilter default What is the effect of this configuration command？（）A、If BPDUs are received by a port configured for PortFast， they are ignored and none are sent.B、The
题目
The following was configured on a switch： Switch（config） # spanning-tree portfast bpdufilter default What is the effect of this configuration command？（）
- A、If BPDUs are received by a port configured for PortFast， they are ignored and none are sent.
- B、The command will enable BPDU filtering on all ports regardless of whether they are configured for BPDU filtering at the interface level.
- C、If BPDUs are received by a port configured for Portfast， the port will transition to forwarding state.
- D、If BPDUs are received by a port configured for PortFast， then PortFast is disabled and the BPDUs are processed normally.
- E、None of the other alternatives apply.
参考答案和解析
相似问题和答案
第1题：
A.The Router1 WAN port is configured as a trunking port.
B.The Router1 port connected to Switch1 is configured using subinterfaces.
C.The Router1 port connected to Switch1 is configured as 10 Mbps.
D.The Switch1 port connected to Router1 is configured as a trunking port.
E.The Switch1 port connected to Host B is configured as an access port.
F.The Switch1 port connected to Hub1 is configured as full duplex.
第2题：
Which spanning-tree command would cause a PortFast-enabled interface to lose its PortFast-operational status and disable BPDU filtering if it receives BPDUs？（）
- A、spanning-tree guard root
- B、spanning-tree portfast bpduguard default
- C、spanning-tree bpduguard enable
- D、spanning-tree bpdufilter enable
- E、spanning-tree portfast bpdufilter default
正确答案:E
第3题：
You have configured a Ezonexam switch as shown below:
Ezonexam3(config-if) switchport port-security
Ezonexam3(config-if) switchport port-security mac-address sticky
Select the action below that results from executing these commands.
A. A dynamically learned MAC address is saved in the VLAN database.
B. A dynamically learned MAC address is saved in the startup-configuration file.
C. Statically configured MAC addresses are saved in the startup-configuration file if frames from that address are received.
D. A dynamically learned MAC address is saved in the running-configuration file.
E. Statically configured MAC addresses are saved in the running-configuration file if frames from that address are received.
F. None of the above
D 解析：Explanation:
With port security, the switch supports these types of secure MAC addresses:
Static secure MAC addresses-These are manually configured by using the switchport port-security mac-address mac-address interface configuration command, stored in the address table, and added to the switch running configuration.
Dynamic secure MAC addresses-These are dynamically configured, stored only in the address table, and removed when the switch restarts.
Sticky secure MAC addresses-These are dynamically configured, stored in the address table, and added to the running configuration. If these addresses are saved in the configuration file, when the switch restarts, the interface does not need to dynamically reconfigure them.
You can configure an interface to convert the dynamic MAC addresses to sticky secure MAC addresses and to add them to the running configuration by enabling sticky learning. To enable sticky learning, enter the switchport port-security mac-address sticky interface configuration command. When you enter this command, the interface converts all the dynamic secure MAC addresses, including those that were dynamically learned before sticky learning was enabled, to sticky secure MAC addresses. The interface adds all the sticky secure MAC addresses to the running configuration.
The sticky secure MAC addresses do not automatically become part of the configuration file, which is the startup configuration used each time the switch restarts. If you save the sticky secure MAC addresses in the configuration file, when the switch restarts, the interface does not need to relearn these addresses. If you do not save the sticky secure addresses, they are lost.
第4题：
Switch R1 has been configured with Private VLANs. With that type of PVLAN port should the default gateway be configured？（）
- A、 Trunk
- B、 Isolated
- C、 Primary
- D、 Community
- E、 Promiscuous
- F、 None of the other alternatives apply
正确答案:E
第5题：
Switch R1 has been configured with the root guard feature. What statement is true if the spanning tree enhancement Root Guard is enabled？ （）
- A、 If BPDUs are not received on a non-designated port， the port is moved into the STP loop- inconsistent blocked state
- B、 IF BPDUs are received on a PortFast enabled port， the port is disabled.
- C、 If superior BPDUs are received on a designated port， the interface is placed into the root- inconsistent blocked state.
- D、 If inferior BPDUs are received on a root port， all blocked ports become alternate paths to the root bride.
正确答案:C
第6题：
Which of the following characteristics describe the BPDU Guard feature（）
- A、ABPDU Guard port should only be configured on ports with PortFast enabled.
- B、BPDU Guard and PortFast should not be enabled on the same port.
- C、BPDU Guard is used to ensure that superior BPDUs are not received on a switch port.
- D、ABPDU Guard port receiving a BPDU will go into err-disablestate.
- E、ABPDU Guard port receiving a BPDU will be disabled.
- F、BPDU Guard can be enabled on any switch port.
正确答案:A,E
第7题：
Which of the following characteristics describe the BPDU Guard feature？（Choose all that apply.）（）
- A、A BPDU Guard port should only be configured on ports with PortFast enabled
- B、BPDU Guard and PortFast should not be enabled on the same port.
- C、BPDU Guard is used to ensure that superior BPDUs are not received on a switch port
- D、A BPDU Guard port receiving a BPDU will go into err-disable state
- E、A BPDU Guard port receiving a BPDU will be disabled
- F、BPDU Guard can be enabled on any switch port
正确答案:A,E
第8题：
A.if a switch that is configured to operate in client mode cannot access a VTP server,then the switch reverts to transparent mode.
B.The local vlan configuration is updated only when an update that has a higher configuration revision number is received.
C.Vtp advertisements are not forwarded to neighboring switches that are configured in vtp transparent mode.
D.When switches in vtp client mode are rebooted,they send a vtp advertisement request to the vtp servers.
E.Vtp client is the default vtp mode
F.On switches that are configured to operate in client mode ,vlans can be created,deleted,or renamed locally
第9题：
A port in a redundant topology is currently in the blocking state and is not receiving BPDUs. To ensure that this port does not erroneously transition to the forwarding state， which command should be configured to satisfy the requirement？（）
- A、Switch（config）#spanning-tree loopguard default
- B、Switch（config-if）#spanning-tree bdpufilter
- C、Switch（config）#udld aggressive
- D、Switch（config-if）#spanning-tree bpduguard
正确答案:A
第10题：
Select the action that results from executing these commands. Switch（config-if）# switchport port-security. Switch（config-if）# switchport port-security mac-address sticky（）
- A、A dynamically learned MAC address is saved in the startup-configuration file.
- B、A dynamically learned MAC address is saved in the running-configuration file.
- C、A dynamically learned MAC address is saved in the VLAN database.
- D、Statically configured MAC addresses are saved in the startup-configuration file if frames from that address are received.
- E、Statically configured MAC addresses are saved in the running-configuration file if frames from that address are received.
正确答案:B