新题库问题请教

allencheng

QUESTION 3
In which circumstance are multiple copies of the same unicast frame likely to be transmitted in a switched
LAN?
A. after broken links are re-established
B. in an improperly implemented redundant topology
C. when upper-layer protocols require high reliability
D. during high traffic periods
E. when a dual ring topology is in use
Answer: E

答案 B 为什么不对？dual ring topology 好像书里没看到过。

QUESTION 12
You are working in a data center environment and are assigned the address range 10.188.31.0/23.You are
asked to develop an IP addressing plan to allow the maximum number of subnets with as many as 30
hosts each.Which IP address range meets these requirements?
A. 10.188.31.0/27
B. 10.188.31.0/26
C. 10.188.31.0/29
D. 10.188.31.0/28
E. 10.188.31.0/25

Answer: B

为什么A不对？不应该是n-2吗？


谢谢指教

红色石头

对于12题，我也选A的，还是坚信自己的算法。。

yrb

这俩题没有问题。

fulltimes

3.应该说BCE都有可能出现这种情况，这里只能选一个最适合的
12.如果不考虑网关选A，考虑网关就需要31个有效地址了，那就得选B了