Huawei H12-821_V1.0 Practice Test - Questions Answers, Page 6
List of questions
Question 51

As shown in the figure, VRRP is associated with a BFD session. When a backup device detects a fault through BFD, the backup device immediately assumes the master role after the Master_Down_Timer timer expires.
TRUE
FALSE
VRRP and BFD Association:
VRRP (Virtual Router Redundancy Protocol) is used to provide gateway redundancy by electing a master and backup router.
Associating VRRP with BFD (Bidirectional Forwarding Detection) allows faster detection of faults on the master device or the link between the master and the backup.
Master_Down_Timer Behavior:
Normally, when a VRRP backup device detects that the master is down (through missed VRRP advertisements), the Master_Down_Timer dictates the failover timing.
However, when VRRP is associated with BFD:
BFD detects faults immediately (sub-second detection).
The backup device does not wait for the Master_Down_Timer to expire. Instead, it immediately assumes the master role upon fault detection by BFD.
Why the Statement is FALSE:
The statement claims that the backup device assumes the master role after the Master_Down_Timer expires when a fault is detected by BFD.
This is incorrect because BFD bypasses the need for the Master_Down_Timer to expire. The backup device transitions to the master role immediately upon BFD detecting a fault.
Conclusion:
The correct behavior of VRRP when associated with BFD is immediate role assumption by the backup device upon fault detection, bypassing the Master_Down_Timer.
Therefore, the statement is FALSE.
Question 52

Which of the following statements is false about BFD?
The asynchronous mode is the primary BFD operating mode.
In asynchronous mode, two systems periodically exchange BFD Control packets at the negotiated interval. If one system does not receive any BFD Control packets from the other within the detection interval, the BFD session is declared down.
The asynchronous mode does not support the echo function.
In demand mode, after a BFD session is set up, the system does not periodically send BFD Control packets.
In asynchronous mode, two devices exchange BFD Control packets to monitor connectivity. However, this mode does support the echo function, which tests bidirectional paths by sending packets that loop back to the origin. This statement is incorrect. Demand mode, on the other hand, minimizes the control packet exchange, relying on periodic echo packets if configured. Huawei's BFD configuration guides emphasize these distinctions .
Question 53

BFD can quickly detect faults in channels at multiple network layers, ensuring high reliability. To which of the following layers does BFD belong?
Application layer
Data link layer
Physical layer
Network layer
BFD operates at the network layer, providing rapid fault detection for forwarding paths, such as IP routing and MPLS tunnels. It interacts closely with network protocols (e.g., OSPF, BGP) to ensure high reliability and quick response to faults. BFD does not belong to the application, data link, or physical layers but functions as a network layer diagnostic tool as confirmed in Huawei's network protocol training .
Question 54

In VRRP networking, if VRRP is not configured to track an uplink interface and the uplink interface or link of the master device in a VRRP group fails, no switchover will be triggered. As a result, a traffic blackhole occurs.
TRUE
FALSE
If VRRP is not configured to track uplink interfaces, a failure in the master device's uplink or link will not trigger a switchover, resulting in a traffic blackhole. The VRRP mechanism relies on interface tracking to monitor connectivity and ensure role transitions upon faults. Without this configuration, no failover occurs, and traffic directed toward the master device is lost .
Question 55

In the SNMP management model, which of the following elements defines the attributes of a managed device?
MIB
Agent
Managed Object
NMS
In SNMP (Simple Network Management Protocol), the MIB (Management Information Base) defines the attributes of a managed device. It acts as a structured database of managed objects, each described by a unique OID (Object Identifier). These objects provide critical information and control interfaces for network management. Other elements like the agent (manages the MIB) and NMS (queries the agent) do not define attributes but interact with the MIB .
Question 56

In inter-AC roaming scenarios, an AC can function as the mobility server of multiple mobility groups, but can be added only to one mobility group.
TRUE
FALSE
In inter-AC roaming scenarios, an AC (Access Controller) can serve as the mobility server for multiple mobility groups, enabling it to manage roaming among multiple groups. However, an AC can only belong to one specific mobility group. This constraint ensures that mobility management remains streamlined and avoids conflicts. Huawei WLAN mobility configuration guides validate this setup .
Question 57

A large shopping mall configures a VLAN pool to prevent network performance deterioration caused by potentially large broadcast domains. A network engineer runs the display vlan pool name STA command to check information about the VLAN pool. The following command output is displayed:
<AC> display vlan pool name STA Name : STA Total : 2 Assignment: hash Threshold Notify Count: 3 Threshold Notify time(min): 3 VLAN ID : 2 4
Which of the following statements are true?
The VLANs with the IDs of 2 and 4 are added to the VLAN pool.
The total number of VLAN pools is 2.
The name of the VLAN pool is STA.
The VLAN pool uses the even VLAN assignment algorithm.
The command output confirms that the VLANs with IDs 2 and 4 are part of the VLAN pool named 'STA.' The VLAN pool concept is used to allocate VLANs dynamically to devices or subnets, which reduces broadcast domain size and improves network efficiency. The total number of VLAN pools is unrelated to this output, and the assignment algorithm (hash or even) is not explicitly mentioned in the output. Huawei VLAN pool management references align with this analysis .
Question 58

STAs stay on different subnets before and after Layer 3 roaming. To enable the STAs to access the original network after roaming, network engineers need to configure user traffic to be forwarded to the original subnet over a CAPWAP tunnel.
TRUE
FALSE
In Layer 3 roaming scenarios, STAs (stations) remain on different subnets before and after roaming. To ensure that user traffic reaches the original subnet, it must be tunneled back over a CAPWAP tunnel. This technique prevents disruptions in communication and enables seamless roaming. Huawei's Layer 3 roaming design guidelines emphasize the use of CAPWAP tunnels for user traffic forwarding .
Question 59

The typical characteristics of the AI era are that it focuses on data, explores data value, and improves AI efficiency. Therefore, the core requirement of AI for data center networks is speed, meaning low latency.
TRUE
FALSE
AI-driven networks focus on maximizing efficiency by minimizing latency to enhance data processing and decision-making speed. The AI era emphasizes leveraging large data volumes and ensuring rapid data center interconnectivity. This makes low latency a critical requirement for AI-ready data center networks, as highlighted in Huawei's AI and data center network optimization materials .
Question 60

Which of the following statements about the forwarding plane of a switch is false?
Provides high-speed and non-blocking data channels.
Can encapsulate and decapsulate packets.
Can collect packet statistics.
Consists of main control boards and interface boards.
The forwarding plane of a switch consists of data forwarding hardware, such as line cards or forwarding engines, and is responsible for tasks like encapsulating/decapsulating packets, providing high-speed data channels, and collecting packet statistics. However, main control boards are part of the control plane, not the forwarding plane. This distinction ensures a separation of data forwarding and control functionalities .
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