26. You have done a partial migration from 802.1D STP to 802.1w STP. Which of the following is true? 你要升级生成树协议从802.1D到802.1W 下面哪个说的是对的
A. 802.1D and 802.1w interoperate only when the 802.1D STP domain supports rapid convergence.
B. Ports leading to 802.1D devices will run in compatibility mode, while the rest of the ports will run in 802.1w mode.
端口已经运行在802.1D下了。需要重新启动端口才能切换到802.1W模式下
C. This is an invalid configuration and a partial migration cannot be done. D. The bridge timers will be set to match the 802.1
D devices. E. A secondary root bridge will always be populated within the 802.1D domain. F. If the root bridge is selected within the 802.1D domain, the whole STP domain will run in 802.1D compatibility mode. G. In partially migrated 802.1w networks, it is recommended to keep the STP diameter below 4.
Answer: B
27. The network administrator is trying to add Switch1 to the network, but the 802.1Q trunk is not coming up. Switch1 was previously tested in the laboratory and its trunk configuration worked fine. What are three possible causes of this problem? (Choose three.)
一个管理员，想增加一台交换机到一个网络，但是802.1Q的TRUNK没有开启。交换机在实验室力测试过同时TRUNK已经配置了，以下那三个说的是对的?
A. The trunking configuration mode on Switch1 is set to Off.
B. The trunking configuration mode on the other end is set to On.
网络另一端的设备TRUNK的模式为ON
C. The trunking configuration mode on the other end is set to Desirable.
网络另一端的设备TRUNK的模式为Desirable
D. Cisco Discovery Protocol is not running on the other end. E. There is a VTP domain name mismatch.
VTP 的域名输入错误了
F. Switch1 does not support 802.1Q.
Answer: BCE
28. You replaced your Layer 3 switch, which is the default gateway of the end users. Many users cannot access anything now, including email, Internet, and other applications, although other users do not have any issues. All of the applications are hosted in an outsourced data center. In order to fix the problem, which one of these actions should you take?
你要更换你的三层交换机。 这是用户的默认网关， 许多用户不能访问网络和电子邮件和其他 应用程序了， 但是另外一些用户没有受到任何影响。 所有的应用程序服务都托管在一个外部 的数据中心。为了解决这个问题，下面哪个是你应该做的
A. Clear the MAC address table in the switch.
B. Clear the ARP cache in the switch.
C. Clear the ARP cache in the end devices.
Answer: C
