Spanning Tree Protocol Questions and Answers updated daily – Networking
15 Spanning Tree Protocol Questions and answers section with explanation for various online exam preparation, various interviews, Networking Spanning Tree Protocol online test. Spanning Tree Protocol Questions with detailed description, explanation will help you to master the topic.
Spanning Tree Protocol Questions
What is the result of segmenting a network with a bridge (switch)?
It increases the number of collision domains.
It decreases the number of collision domains.
It increases the number of broadcast domains.
It decreases the number of broadcast domains.
It makes smaller collision domains.
It makes larger collision domains.
Correct Ans:1 and 5
Bridges break up collision domains, which would increase the number of collision domains in a network and also make smaller collision domains.
2. If a switch receives a frame and the source MAC address is not in the MAC address table but the destination address is, what will the switch do with the frame?
Correct Ans:Add the source address and port to the MAC address table and forward the frame out the destination port
Since the source MAC address is not in the MAC address table, the switch will add the source address and the port it is connected to into the MAC address table and then forward the frame to the outgoing port.
What command will display the forward/filter table
Correct Ans:show mac address-table
The command show mac address-table displays the forward/filter table on the switch.
You need to allow one host to be permitted to attach dynamically to each switch interface. Which two commands must you configure on your catalyst switch to meet this policy?
Switch(config-if)# ip access-group 10
Switch(config-if)# switchport port-security maximum 1
Switch(config)# access-list 10 permit ip host 1
Switch(config-if)# switchport port-security violation shutdown
Switch(config)# mac-address-table secure
Correct Ans:2 and 4
The switchport port-security is an important command, and it's super easy with the CNA; however, from the CLI, you can set the maximum number of MAC addresses allowed into the port, and then set the penalty if this maximum has been passed.
5. Which of the following is a layer 2 protocol used to maintain a loop-free network?
The Spanning Tree Protocol is used to stop switching loops in a switched network with redundant paths.
6. You want to run the new 802.1w on your switches. Which of the following would enable this protocol?
Correct Ans:Switch(config)# spanning-tree mode rapid-pvst
802.1w is the also called Rapid Spanning Tree Protocol. It is not enabled by default on Cisco switches, but it is a better STP to run since it has all the fixes that the Cisco extensions provide with 802.1d.
Your switch has a port status LED that is alternating between green and amber. What could this indicate?
Correct Ans:The port is experiencing errors.
When you connect to a switch port, at first the link lights are orange/amber, and then they turn green, indicating normal operation. If the link light is blinking, you have a problem.
Layer 2 switching provides which of the following?
Hardware-based bridging (ASIC)
Correct Ans:All of the above
Switches, unlike bridges, are hardware based. Cisco says its switches are wire speed and provide low latency, and I guess they are low cost compared to their prices in the 1990s.
9. You have two switches connected together with two crossover cables for redundancy, and STP is disabled. Which of the following will happen between the switches?
Correct Ans:Broadcast storms will occur on the switched network.
If spanning tree is disabled on a switch and you have redundant links to another switch, broadcast storms will occur, among other possible problems.
Which of the following statement is true?
Correct Ans:A switch creates separate collision domains but one broadcast domain. A router provides a separate broadcast domain.
Switches break up collision domains, and routers break up broadcast domains.
If you want to disable STP on a port connected to a server, which command would you use?
Correct Ans:spanning-tree portfast
If you have a server or other devices connected into your switch that you're totally sure won't create a switching loop if STP is disabled, you can use something called portfast on these ports. Using it means the port won't spend the usual 50 seconds to come up while STP is converging.
In which circumstance are multiple copies of the same unicast frame likely to be transmitted in a switched LAN?
Correct Ans:In an improperly implemented redundant topology
If the Spanning Tree Protocol is not running on your switches and you connect them together with redundant links, you will have broadcast storms and multiple frame copies.
What does a switch do when a frame is received on an interface and the destination hardware address is unknown or not in the filter table?
Correct Ans:Floods the network with the frame looking for the device
Switches flood all frames that have an unknown destination address. If a device answers the frame, the switch will update the MAC address table to reflect the location of the device.
14. Which statement describes a spanning-tree network that has converged?
Correct Ans:All switch and bridge ports are in either the forwarding or blocking state.
Convergence occurs when all ports on bridges and switches have transitioned to either the forwarding or blocking states. No data is forwarded until convergence is complete. Before data can be forwarded again, all devices must be updated.
15. What is the purpose of Spanning Tree Protocol in a switched LAN?
Correct Ans:To prevent switching loops in networks with redundant switched paths
The Spanning Tree Protocol (STP) was designed to stop layer 2 loops. All Cisco switches have the STP on by default.