Question 1

What command will display the forward/filter table?

Accepted Answer

The command show mac address-table displays the forward/filter table on the switch.

Question 2

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?

Accepted Answer

If spanning tree is disabled on a switch and you have redundant links to another switch, broadcast storms will occur, among other possible problems.

Question 3

Layer 2 switching provides which of the following? Hardware-based bridging (ASIC) Wire speed Low latency Low cost

Accepted Answer

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.

Question 4

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…

Accepted Answer

Bridges break up collision domains, which would increase the number of collision domains in a network and also make smaller collision domains.

Question 5

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?

Accepted Answer

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.

Question 6

Which of the following statement is true?

Accepted Answer

Switches break up collision domains, and routers break up broadcast domains.

Question 7

What are the distinct functions of layer 2 switching that increase available bandwidth on the network? Address learning Routing Forwarding and filtering Creating network loops Loop avoidance IP addressing

Accepted Answer

Layer 2 features include address learning, forwarding and filtering of the network, and loop avoidance.

Question 8

In which circumstance are multiple copies of the same unicast frame likely to be transmitted in a switched LAN?

Accepted Answer

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.

Question 9

Which of the following is a layer 2 protocol used to maintain a loop-free network?

Accepted Answer

The Spanning Tree Protocol is used to stop switching loops in a switched network with redundant paths.

Question 10

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-se…

Accepted Answer

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.

Question 11

You want to run the new 802.1w on your switches. Which of the following would enable this protocol?

Accepted Answer

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.

Question 12

Which statement describes a spanning-tree network that has converged?

Accepted Answer

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.

Question 13

What is the purpose of Spanning Tree Protocol in a switched LAN?

Accepted Answer

The Spanning Tree Protocol (STP) was designed to stop layer 2 loops. All Cisco switches have the STP on by default.

Question 14

Your switch has a port status LED that is alternating between green and amber. What could this indicate?

Accepted Answer

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.

Question 15

If you want to disable STP on a port connected to a server, which command would you use?

Accepted Answer

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.

Question 16

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?

Accepted Answer

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.

Spanning Tree Protocol Questions