情人节题库435题不解之处

shabi101

QUESTION 435
Which three statements accurately describe layer 2 Ethernet switches?(choose three)

A. Microsegmentation decreases the number of collisions on the network.
B. if a switch receives a frame for an unkown destination,it uses ARP to resolve the address.
C. Spanning Tree Protocol allows switches to automatically share vlan information.
D. In a properly functioning network with redundant switched paths,each switched aegment will contain one
root bridge with all its ports in the forwarding state.All other switches in that broadcast domain will have
only one root port.
E. Establishing vlans increases the number of broadcast domains.
F. Switches that are configured with vlans make forwarding decisions based on both layer 2 and layer 3
address information.

题库给的答案是ADF

我的疑问主要在E和F上。题库的解释是E的广播域不合题意。但我的理解如下：

二层交换机，即使配置过VLAN，在转发数据帧的时候也没有基于三层信息。因为二层交换机根本不认识三层封装，就没有那个功能。拥有Inter-VLAN的数据转发的是三层交换机或者路由器，二层交换机在收到VLAN数据帧后也就是根据自己的VLAN表把这个帧广播到对应的端口上去，这个VLAN表跟三层没有关系，最多算个2.5层，就像MPLS一样。

所以排除的话，F应该被排除掉。

请各位大拿给解释解释。

peterwaiyip

我也同意你的看法.
我也在其他题库看过这道题,给的答案是ADE.