Exam 200-120 Question id=124 Troubleshooting

switch# sh spanning-tree vlan 1 VLAN0001 Spanning tree enabled protocol rstp Root ID Priority 30482 Address 0017.9425.fc00 Cost 38 Port 1 (FastEthernet0/1) Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec Bridge ID Priority 32769 (priority 32768 sys-id-ext 1) Address 0013.19a3.e5c0 Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec Aging Time 300 Interface Role Sts Cost Prio.Nbr Type ---------------- ---- --- --------- -------- -------------------------------- Fa0/1 Root FWD 19 128.1 P2p Fa0/2 Desg FWD 38 128.1 P2p Fa0/3 Desg FWD 38 128.1 P2p Fa0/4 Desg FWD 38 128.1 P2p

Why has this switch not been elected the root bridge for VLAN1?

A. It has more than one interface that is connected to the root network segment.
B. It is running RSTP while the elected root bridge is running 802.1d spanning tree.
C. It has a higher MAC address than the elected root bridge.
D. It has a higher bridge ID than the elected root bridge.

When a switch receives a BPDU, it first compares priority, the lower number wins. If a tie, compare MAC, the smaller one wins. Here Switch has 32769 priority which is greater than 20481 so switch will not elect for root bridge. It says the bridge priority for Switch is 32769, and the root priority is 30482.



WARNING

the answers are mixed, do not specify in the comment number or the letter of the answer
please write answer#A instead A, answer#B instead B...
Subject:

only logged users can write comments