Refer to the exhibit.
Given the output shown from this Cisco Catalyst 2950, what is the reason that interface FastEthernet
0/10 is not the root port for VLAN 2?
A.
This switch has more than one interface connected to the root network segment in VLAN 2.
B.
This switch is running RSTP while the elected designated switch is running 802.1d Spanning Tree.
C.
This switch interface has a higher path cost to the root bridge than another in the topology.
D.
This switch has a lower bridge ID for VLAN 2 than the elected designated switch.
Explanation:
These four parameters are examined in order to make root bridge , root port , designated port.
Other switch has lowest Sending Bridge ID or Sending Port ID so vlan 2 is not the root port.
1. A lower Root Bridge ID2. A lower path cost to the Root3. A lower Sending Bridge ID4. A lower
Sending Port ID
The cost that is factored by STP is ONLY the local ethernet medium that is used. STP is NOT a routing protocol and cannot sum up the cost of a path. Always remember that STP ONLY refers to the next “hop” at the layer 2 level. The way that this would differ is if there is a different connected (such as Gi0/0 vs Fa0/0). STP will select the ethernet medium that is known to be the fastest.
Anyways, since the cost is the same for the three interfaces and we are only interested in VLAN 2, we are now examining that VLAN 2 is selected as an alternate(blocking) port to the root of VLAN 2. because the priority is greater than 128.1 and this is an alternate port, we can safely assume that another switch has a lower(better) bridge ID.
Please review STP technologies, as they will make up %21 of the exam.
JAYNONIMOUS are you saying the answer is wrong?
it should be D, lower bridge ID
nvm…..
answer C is correct, it is in blk state because it has more path-cost to the root switch that the other sw in the same segment
d is not correct
agreed