A network engineer is extending a LAN segment between two geographically separated data
centers. Which enhancement to a spanning-tree design prevents unnecessary traffic from crossing
the extended LAN segment?
A.
Modify the spanning-tree priorities to dictate the traffic flow.
B.
Create a Layer 3 transit VLAN to segment the traffic between the sites.
C.
Use VTP pruning on the trunk interfaces.
D.
Configure manual trunk pruning between the two locations.
I wonder why C. could be the right answer: what’s the link between “enhanced spanning-tree design” and “VTP pruning”? What about D. as right answer instead?
I was thinking of the link between STP and VTP. I thought of answer A because it s related to STP more than preventing unnecessary traffic. Could be D as well – not very much related to STP imo, but more preventing the unwanted traffic.
Answers C and D are both correct, however, manual pruning is not really an enhancement to STP. VTP pruning is “more” of an enhancement to STP than manual pruning so that is why the answer is C.
hi Slothar, for us beginners, please elaborate, how is VTP running related to STP?
The question does not ask for STP technology but Spanning Tree design aka Layer 2 design. VTP is not directly related to Spanning Tree Protocol.
1. If the question would ask for only preventing unnecessary traffic, then C. might be more comfortable than D – IF VTP ist used! Anyway, both would work. But because the question gives no hint if VTP is used or not in this scenario, I would prefer D.
2. If I’m not wrong, only D. would be an enhancement to STP, because VTP pruning (C.) does not enhance the STP
“VTP-pruned VLANs on a trunk are still part of the spanning tree. Therefore, VTP-pruned VLANs do not reduce the number of spanning tree port instances.”
https://www.cisco.com/c/en/us/support/docs/lan-switching/vtp/98155-tshoot-vlan.html
What do you think?