CCNP交换题，93题,求助

gbcbooks

QUESTION 93
A network engineer configured an Ethernet switch using these commands.
Switchone(config) # Spanning-tree portfast bpdufilter default Which statement about the spanning-tree
portfast feature on the switch is true?
A. If an interface is enabled for portfast receives BDPU, the port goes through the spanning-tree listening,
learning, and forwarding states.
B. If an interface is enabled for portfast receives BDPU, the port does not go through the spanning-tree
listening, learning, and forwarding states.
C. If an interface is enabled for portfast receives BDPU, the port is shut down immediately.
D. If an interface is enabled for portfast receives BDPU, the port goes into the spanning-tree inconsistent
state.
Correct Answer: A

1，如果我在一个trunk端口上启了用portfast，然后shutdown 再no shutdown,
这个端口不是立即进入forwarding吗？还会经过listening和learning ?
2，如果我在一个access端口上启用portfast,对端是个trunk接口，
那这个接口是会收到BPDU后，会把这个接口BLN*掉。
如下：


IOU1#sh spanning-tree interface e0/0

Vlan                Role Sts Cost      Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
VLAN0001            Desg BKN*100       128.1    P2p Edge *TYPE_Inc
IOU1#sh run inte
IOU1#sh run interface e0/0
Building configuration...

Current configuration : 174 bytes
!
interface Ethernet0/0
switchport trunk encapsulation dot1q
switchport mode access
duplex auto
spanning-tree portfast trunk
spanning-tree link-type point-to-point
end

IOU1#

所以，关于这题，想想大家有没有不同的理解。

IamNotWolf

1、只要是trunk启用portfast，接口不经历STP状态，cisco文档见过
用真机以前做过
2、你是对的，但如果你不打全局过滤，其实也要处于不一致状态

bw126

这题我也是有点疑问的，不过我用排除法来看C D肯定不对了。
B的话如果说没有到forwarding的话也不对，所以只能选择A了。