Quick Spanning Tree Protocol question

masadull

I was doing a practice exam and need confirmation on the answer they have given - I think they are wrong -

A switch has 3 ports Fa0/1, Fa0/2, and Fa0/3. STP is in use, with:

Fa0/3 in "Blocking" state
Fa0/2 is connected to a PC
Fa0/1 connected to another switch

The question asks which port on this switch are receiving BPDUs?

A. Fa 0/1 only
B. Fa 0/2 only
C. Fa 0/3 only
D. Fa 0/1 and Fa 0/2 only
E. Fa 0/1 and Fa 0/3 only
F. All three ports

THEIR ANSWER: E

I think it should be D. Please help. Thanks a bunch.

mikeyoung

Their answer is correct. See the discussion at this link:

http://www.cisco.com/univercd/cc/td/doc/product/rtrmgmt/sw_ntman/cwsimain/cwsi2/cwsiug2/vlan2/stpapp.htm

Good luck,

Mike

badboyziggy

Yeah the answer is correct when in blocking state the port listens to bpdus but they dont forward any frames.

masadull

Thanks guys, reading that link on STP now. Didnt know that a port in blocking state still listens, but I guess it has to, in case it needs to change the state of that port to forwarding - makes sense.

patelhari

ya they are right coz blocking mode will receive bpdus but dont forward and f0/2 is not correct coz it is connected to pc.