关于115题库28题答案请教

PrepKing

QUESTION 28
Pilot testing of the new switching infrastructure finds that when the root port is lost, STP immediately
replaces the root port with an alternative root port. Which spanning-tree technology is used to accomplish
backup root port selection?
A. PVST+
B. PortFast
C. BackboneFast
D. UplinkFast
E. Loop Guard
F. UDLD
Correct Answer: D

我看论坛上的1000分战报说这题答案是B，请大家帮忙看看。
1、考试共44道题，题库全部覆盖。3 K6 x/ f3 c$ k7 t6 ], X  i& P
2、实验题敲命令的3道必考，实验case题3选2。4 m8 A! _; |+ d. ~, q, f
3、端口组格式：int range fa0/3(空格）-（空格）4。
4、实验题配到最后的copy running-config  startup-config  照打（建议两次）。
5、多为单项选择题，其中题库有两题答案是错的：Q14应为单选，选transparent mode；Q28应为单选，选 portfast 。# |'

fu720701

這題答案肯定是UplinkFast，請參考以下內容

The UplinkFast feature is designed to run in a switched environment when the switch has at least one alternate/backup root port (port in blocking state), that is why Cisco recommends that UplinkFast be enabled only for switches with blocked ports, typically at the access-layer. Do not use on switches without the implied topology knowledge of a alternative/backup root link typically to distribution and core switches in Cisco multilayer design.
URL:
http://www.cisco.com/c/en/us/sup ... tocol/10575-51.html

PrepKing

明白，谢谢回复。

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