Chapter 3 LESSON REVIEW

What should be investigated if a broadcast storm occurs despite spanning tree being enabled?

Compatible versions of Spanning Tree Protocol on all switches

Which feature is commonly associated with managed switches but not with unmanaged switches?

Configuration of switch settings

A company's data center is experiencing network bottlenecks due to increased traffic between their storage servers and the main network switch. The storage servers each have four 1 Gbps network interfaces, and the main switch supports link aggregation. The IT manager decides to implement link aggregation to alleviate the bottleneck. What configuration should be applied to effectively increase the bandwidth and alleviate the network bottleneck?

Configuring the server's network interfaces in LACP active mode and the corresponding switch ports in LACP passive mode is the correct answer. Configuring the server's network interfaces in LACP active mode and the corresponding switch ports in LACP passive mode ensures that the link aggregation group (LAG) is formed. The server actively attempts to form the LAG with the switch, which is set to passively accept. This configuration effectively combines the bandwidth of the four 1 Gbps interfaces into a single logical connection, increasing bandwidth and alleviating the bottleneck.

You are configuring a network analyzer to monitor traffic on your company's network. Your primary goal is to capture IPv4 and IPv6 traffic for analysis. To achieve this, you decide to filter traffic based on the EtherType field in Ethernet frames. Given your objective, which EtherType values should you configure the network analyzer to filter for?

EtherType value 0x0800 is used to indicate an IPv4 packet, and 0x86DD is used for IPv6. Filtering for these values will capture the desired IPv4 and IPv6 traffic.

Which of the following is a unique identifier for each Ethernet network interface port?

MAC Addresses

An IT team responsible for a small corporate network is attempting to increase data throughput to a particular machine from 1 Gbps to 2 Gbps. The machine has two network interface cards. Which Ethernet switching feature would fulfill the IT team requirements?

NIC teaming

What happens if both sides of a link aggregation are set to passive mode?

No bonded channel is created.

When troubleshooting a broadcast storm caused by a network loop, which physical aspect should you inspect first? (Select two.)

Patch cables connecting two ports on the same switch. One common cause of a network loop, leading to a broadcast storm, is when patch cables improperly connect two ports on the same switch, creating a physical loop. Inspecting and correcting these connections can resolve the loop and stop the broadcast storm. This is a critical first step in troubleshooting physical network issues related to broadcast storms. Physical ports that correspond to disabled interfaces. When troubleshooting a broadcast storm, especially in networks where spanning tree protocol (STP) is enabled, it's important to inspect physical ports that correspond to interfaces disabled by STP due to its loop prevention mechanism. These disabled interfaces can indicate where the network loop might have occurred. By physically inspecting these ports for improperly connected cables or looped connections, such as a cable connecting two ports on the same switch or a cable connecting two wall ports in an office, you can identify and rectify the physical loop causing the broadcast storm. This approach is a direct method for locating and resolving physical loops in the network infrastructure.

A small startup company has set up its initial office network using a hub to connect all employee computers. As the company grows, the network administrator notices an increase in network collisions and a decrease in overall network performance, especially during peak hours. The administrator is considering network infrastructure upgrades to address these issues. Which of the following actions would most effectively reduce network collisions and improve performance in the company's network?

Replace the hub with a switch.

As a network engineer, you are tasked with troubleshooting intermittent network issues that have been reported by users in your organization. You suspect that some of the Ethernet frames being transmitted across the network might be corrupted. To confirm your suspicion, you decide to utilize a tool that analyzes Ethernet frames for errors. Specifically, you want to focus on the integrity of the frames by examining a particular field within them. Which field should you instruct the tool to analyze for detecting potential frame corruption?

The Cyclic Redundancy Check (CRC), also known as the Frame Check Sequence (FCS), is a 32-bit checksum used to detect errors in Ethernet frames. By analyzing the CRC field, the tool can determine if a frame has been corrupted during transmission, making it the correct choice for this scenario.

Which statement best describes the relationship between a broadcast domain and the use of the MAC address ff:ff:ff:ff:ff:ff?

The MAC address ff:ff:ff:ff:ff:ff is used to send a frame to all devices within the same broadcast domain.

What is the primary purpose of a MAC address table in a switch?

The MAC address table is used by a switch to learn and store the MAC addresses of devices that are connected to its ports. This allows the switch to efficiently forward frames to the correct port based on the destination MAC address. Options A, C, and D are incorrect because assigning IP addresses, filtering unauthorized access, and increasing internet speed are not functions of the MAC address table.

In a switched environment, under which condition are runt frame errors and collisions most likely to occur?

The correct answer is when a legacy hub device is connected to a switch and there is a duplex mismatch. Runt frame errors and collisions are most likely to occur in a switched environment when a legacy hub device is connected to a switch and there is a duplex mismatch. This setup can lead to collisions because hubs operate in half-duplex, causing devices to transmit simultaneously, resulting in collisions and consequently runt frames. Duplex mismatches exacerbate this issue by further disrupting the normal flow of traffic.

During a network audit, an auditor is reviewing the MAC addresses of devices connected to the corporate network. One of the devices has a MAC address of FF:FF:FF:11:22:33. The auditor needs to determine the nature of this address. What is the correct classification of this MAC address based on its format?

The presence of 'FF:FF:FF' at the start of the MAC address does not necessarily indicate a broadcast address in this context. Instead, the key is the I/G bit, which, if set to 1 (as indicated by the first byte being an odd number, in this case, FF), signifies a multicast address. This address is used for sending frames to a group of devices.

Your company has recently expanded its network by adding several new switches. After the expansion, you've noticed intermittent network outages and slow performance. Upon investigation, you discover that the root bridge of your Spanning Tree Protocol (STP) configuration is a switch located on the edge of the network, which is connected via a low-bandwidth link. What is the MOST likely cause of the network issues, and what action should you take to resolve them?

The root bridge is located on a low-bandwidth link, causing a bottleneck. You should decrease the priority value of a core switch to elect it as the new root bridge.

In the context of stackable switches, what does the notation "GigabitEthernet 3/0/2" represent?

The second port on the first slot of the third module in the stack Incorrect answer:

During routine monitoring, a network administrator notices that one of the switch interfaces, which is part of a link aggregation group, is showing as suspended. The administrator needs to determine why the port is suspended and what steps to take to resolve the issue. What command should the administrator use to gather the necessary information about the link aggregation group and its member ports?

The show etherchannel summary command provides a summary of the EtherChannel (link aggregation group) status, including the status of individual member ports. This command is specifically designed to diagnose issues related to EtherChannels, such as suspended ports, by showing whether ports are properly aggregated and if there are any negotiation issues.

What is the purpose of using jumbo frames?

To increase the maximum transmission unit (MTU) for efficiency

What happens when VLANs are configured on a switch?

When VLANs (Virtual Local Area Networks) are configured on a switch, it divides the network into multiple broadcast domains. This allows for better traffic management and increases network security by segregating different parts of the network at the data link layer. VLANs do not cause the switch to operate in half-duplex mode, support only legacy network cards, or significantly reduce the switch's performance.

Which of the following commands transitions a user from User EXEC mode to Privileged EXEC mode in a Cisco device?

enable