v200 813一题答案不一致，大家分析下？

红色石头

Which two statements correctly describe characteristics of the PortFast feature?(Choose two.)
A. STP will be disable on the port.
B.Portfast can also be configured on trunk ports
C.Portfast is required to enable port-based BPDU guard
D.Port-fast is used for both STP and RSTP host ports
E.Portfast is used for STP-only host ports

Answer:BD

题库中，有两道给出的答案不一样。。。。不知道大家的分析是怎么样的？指教。。。。

小乔

个人觉得选CD

huluo520

记得楼主问过相关问题，考试的时候，选BD就行了。另参照一下，老外的回答：
B - The option is right. Portfast can also be configured on trunk ports. There is a special command in Cisco IOS 'spanning-tree portfast trunk' which is used only for Router-on-a-stick trunk configuration and not used anywhere else.


D - The option is right. Portfast is used for both STP and RSTP. The default operation mode in Cisco switches is STP with PVST. To configure the mode to RSTP, as per cisco's suggestion, we have to manually configure portfast by the command 'spanning-tree portfast'

红色石头

huluo520 发表于 2011-8-14 20:51

                               
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记得楼主问过相关问题，考试的时候，选BD就行了。另参照一下，老外的回答：
B - The option is right. Por ...

All right,i think so

dugengyu

{:soso__11379473731916659809_3:}选BD，至于你选不选，我反正选了

红色石头

我本来选的，至于你信不信，反正我信了。。。。。

Hyacinth

这题是BD。C答案Portfast is required to enable port-based BPDU guard。开启portfast没被要求开启BPDU guard吧？
E.Portfast is used for STP-only host ports。Portfast 还可以在trunk 端口上用，不信自己做下实验。所以答案BD是对的！！