New CCNA – STP 2

New CCNA – STP 2

Note: If you are not sure about Spanning Tree Protocol, please read our Spanning Tree Protocol STP Tutorial (Premium Tutorial).

Question 1

Three switches are connected to one another via trunk ports. Assuming the default switch configuration, which switch is elected as the root bridge for the spanning-tree instance of VLAN 1?

A. the switch with the highest MAC address
B. the switch with the lowest MAC address
C. the switch with the highest IP address
D. the switch with the lowest IP address



Answer: B

Question 2

Based on the network shown in the graphic



Which option contains both the potential networking problem and the protocol or setting that should be used to prevent the problem?

A. routing loops, hold down timers
B. Switching loops, split horizon
C. routing loops, split horizon
D. Switching loops, VTP
E. routing loops, STP
F. Switching loops, STP

 

Answer: F

Question 3

Refer to the exhibit. Which switch provides the spanning-tree designated port role for the network segment that services the printers?



A. Switch1
B. Switch2
C. Switch3
D. Switch4

 

Answer: C

Explanation

First, the question asks what switch services the printers, so it can be Switch 3 or Switch 4 which is connected directly to the Printers.

Next, by comparing the MAC address of Switch 3 and Switch 4 we found that the MAC of Switch 3 is smaller. Therefore the interface connected to the Printers of Switch 3 will become designated interface and the interface of Switch 4 will be blocked. The picture below shows the roles of all ports:

 



DP: Designated Port
RP: Root Port
BP: Blocked Port

(Please notice that Switch 1 will become the root bridge because of its lowest priority, not Switch 3)