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H12-891 Huawei Practice Test Questions and Exam Dumps

Question 1:

For telemetry data transmission, the data can be transferred between devices and collectors using the TLS protocol. TLS must be configured for data encryption if the data is transmitted using gRPC.

A. True
B. False

Answer: A. True

Explanation:

Telemetry plays a crucial role in modern network management by enabling devices to send real-time performance and status data to monitoring systems or collectors. This information helps network administrators detect issues, optimize performance, and ensure smooth operations. The data collected can include device metrics, such as CPU usage, memory consumption, network traffic, and error rates, among others. This data is invaluable for maintaining network health, troubleshooting problems, and performing predictive maintenance.

One of the communication protocols commonly used for pushing telemetry data is gRPC (Google Remote Procedure Call). gRPC is a high-performance, open-source remote procedure call framework that facilitates the efficient and reliable transfer of data between devices and collectors over a network. It uses HTTP/2 for transport, making it ideal for high-speed, low-latency communication. This makes gRPC a popular choice for transmitting telemetry data in large-scale, distributed environments like data centers, cloud infrastructures, and IoT systems.

However, when sensitive data is being transmitted, such as telemetry information from network devices, ensuring the security of that data during its transmission is paramount. Transport Layer Security (TLS) is the standard security protocol used to provide confidentiality and integrity to data transmitted over networks. TLS encrypts the data, ensuring that any information exchanged between devices and collectors is shielded from unauthorized access, tampering, or interception by malicious actors. Without encryption, any telemetry data sent over the network could be exposed to threats such as eavesdropping or man-in-the-middle attacks, putting sensitive operational information at risk.

In the case of gRPC, TLS encryption is essential because gRPC itself does not provide built-in encryption. When gRPC is used for pushing telemetry data, the communication between the sending device and the collector can potentially pass through insecure channels if not properly secured. This makes it vital to configure TLS for any gRPC-based telemetry setup. This not only secures the data but also ensures that the integrity of the data is preserved, making it impossible for unauthorized parties to alter the transmitted information.

Now, considering the alternative, Option B suggests that TLS is not necessary for gRPC-based telemetry, which is incorrect. While it is true that gRPC can function without encryption, in environments where security and confidentiality are crucial, it is highly advisable to implement TLS. Without TLS, any telemetry data, which could include sensitive network configuration details or performance metrics, would be transmitted in plain text. This opens up the possibility for attackers to intercept the data, which could lead to serious security vulnerabilities, breaches, and unauthorized control over network devices.
Question 2:

Before enabling NETCONF on Huawei network devices, SSH must be configured.

A. True
B. False

Answer: A. True

Explanation:
NETCONF (Network Configuration Protocol) is an IETF standard used to manage network devices and retrieve configuration data. NETCONF operates over SSH (Secure Shell) for secure communication, ensuring that data transmission between the network devices and management systems is encrypted and protected from unauthorized access.

For NETCONF to be enabled on Huawei network devices, SSH must first be configured. This is because SSH provides the underlying secure transport mechanism for NETCONF communications. NETCONF relies on SSH as its transport protocol to provide encryption, authentication, and integrity for the data exchanged between the network devices and the management system.

Without configuring SSH on the Huawei device, it won't be able to securely exchange data via NETCONF, and enabling NETCONF would not be possible. This is why Option A is correct.

Let’s consider why Option B is incorrect:

• Option B is incorrect because SSH is a prerequisite for NETCONF to function. Without SSH, NETCONF communication cannot occur as the protocol relies on SSH for secure data transmission.

Question 3:

SR is a technology that forwards data packets based on source IP addresses.

A. True
B. False

Answer: B. False

Explanation:
SR (Segment Routing) is a modern traffic engineering technology used in computer networking to simplify packet forwarding decisions and increase the efficiency of the network. Segment Routing forwards data packets using segments, which are predefined instructions or identifiers that dictate how packets should be processed at each hop across the network.

However, SR does not forward packets based on source IP addresses. Instead, Segment Routing uses a sequence of segments (which can include source routing instructions) embedded in the packet itself. These segments typically refer to predefined paths or network segments within a Segment Routing domain. The packet is then forwarded based on these segments rather than using traditional routing protocols like IP routing, which might route packets based on the destination IP address and sometimes the source IP address.

In Segment Routing, the decision-making process revolves around the segments specified in the packet's header, not the source IP address. The main goal is to provide better traffic engineering, load balancing, and path control within the network, without needing complex protocols like MPLS (Multiprotocol Label Switching).

Now, let’s see why Option A is incorrect:

• Option A is incorrect because Segment Routing does not use the source IP address to forward data packets. Instead, it uses the segment list or instructions defined for routing, which may involve path steering, load balancing, or failure recovery mechanisms. The forwarding decision is based on segments, not the source IP address.

Question 4:

Segment Routing (SR) is a technology designed to forward data packets on a network using the source routing paradigm. SR-MPLS, as implied by its name, is Segment Routing based on MPLS label forwarding.

A. True
B. False

Answer: A. True

Explanation:
Segment Routing (SR) is a modern network forwarding technique that uses the source routing paradigm. In source routing, the sender of a packet determines the route the packet will take through the network, rather than relying on intermediate routers to determine the route based on destination addresses.

In Segment Routing, each router in the network uses a series of segments, which are predefined instructions that guide the packet along the path. These segments can be encoded directly in the packet header, eliminating the need for complex routing tables and reducing protocol overhead.

One of the most common implementations of Segment Routing is SR-MPLS. SR-MPLS (Segment Routing based on MPLS label forwarding) integrates the principles of Segment Routing with the established Multiprotocol Label Switching (MPLS) protocol. In SR-MPLS, the network uses MPLS labels as segments. Each label instructs the router on how to forward the packet, guiding it through predefined paths based on the source’s instructions.

This combination of Segment Routing with MPLS label forwarding enhances traffic engineering and path optimization in the network, allowing for flexible and scalable routing without the complexity of traditional MPLS-based networks.

Now, let’s look at why the other option is incorrect:

• Option B is incorrect because SR-MPLS is indeed based on the source routing paradigm and uses MPLS labels as segments for forwarding. This enables precise control over traffic paths and efficient management of network resources.

Question 5:

In 6PE and 6VPE networks, there is no need to create a VPN instance on Provider Edge (PE) routers.

A. True
B. False

Answer: B. False

Explanation:
6PE (IPv6 Provider Edge) and 6VPE (IPv6 Virtual Private Edge) are technologies used to extend IPv6 connectivity across an IPv4 MPLS network. These technologies enable the transmission of IPv6 traffic over an MPLS infrastructure that is primarily designed for IPv4 traffic.

In these networking configurations, Provider Edge (PE) routers play a crucial role. These routers connect the MPLS network to the customer networks and are responsible for encapsulating and forwarding packets between different types of networks.

However, despite the fact that 6PE and 6VPE technologies allow IPv6 traffic to be transported over an IPv4 MPLS backbone, they still require the creation of VPN instances on PE routers. These VPN instances are necessary to ensure that the correct routing policies and forwarding behaviors are applied for the various customer traffic flows, particularly for isolating and managing different VPNs.

For 6PE, the VPN instance is responsible for mapping the IPv6 prefixes to the MPLS labels, ensuring that the correct label is attached to IPv6 traffic as it is forwarded across the MPLS network. Similarly, in 6VPE, VPN instances are required to enable the correct label-switching and to manage the different IPv6 VPNs.

Without configuring these VPN instances on the PE routers, the MPLS network would not be able to handle IPv6 traffic properly, as the routers would not have the necessary information to forward packets correctly based on their labels and associated VPN instances.

Now, let’s review why Option A is incorrect:

• Option A is incorrect because VPN instances must be created on PE routers to correctly forward and encapsulate IPv6 traffic across the MPLS backbone in both 6PE and 6VPE networks. Without these instances, proper routing and forwarding cannot occur, and the VPN traffic would not be isolated or routed properly within the MPLS network.

Question 6

The command display current-configuration shows the running configuration stored in memory.

A. True
B. False

Answer: A. True

Explanation:
The command display current-configuration is commonly used on network devices, especially in Huawei devices running the Huawei VRP (Versatile Routing Platform) operating system, to display the current configuration that is actively running in the system's memory. The "running configuration" refers to the configuration settings that the device is currently using, and it is stored in the device's volatile memory (RAM). This is in contrast to the startup configuration, which is saved in non-volatile memory (NVRAM) and is loaded when the device is rebooted.

The command provides a detailed output of the device’s current configuration, which includes settings related to routing, interfaces, security, VLANs, and more. The current configuration is dynamic and reflects any changes made to the device configuration since the last reboot or since the last time the configuration was saved.

Understanding the difference between the running configuration and startup configuration is crucial in network management. The running configuration can be modified in real-time, and changes will be lost if not saved. If the device is rebooted without saving the running configuration, the device will revert to using the startup configuration, which might not include any recent changes.

Thus, Option A is correct because the display current-configuration command indeed shows the running configuration stored in memory. Option B is incorrect because it contradicts the functionality of the command.

Question 7

In a firewall hot standby configuration, heartbeat interfaces can be connected either directly or via an intermediary device such as a switch or router.

A. True
B. False

Answer: A. True

Explanation:
In a firewall hot standby scenario, two firewalls are configured to work together to provide redundancy and high availability. This type of configuration is typically known as High Availability (HA). The main idea behind HA is to ensure that if one firewall fails, the other can take over without interrupting service to the network. This failover is triggered by the heartbeat signal between the two firewalls.

The heartbeat interfaces are responsible for monitoring the health of both firewalls in the HA pair. These interfaces send periodic "heartbeat" signals to each other to ensure that both devices are operational. If one firewall fails to send a heartbeat within a specific timeframe, the other firewall assumes that the failed unit is down and takes over its role.

These heartbeat interfaces can indeed be connected in multiple ways, depending on the network design. The interfaces can be directly connected to each other, meaning that each firewall has a direct, point-to-point connection. Alternatively, they can be connected through an intermediate device such as a switch or router. This flexibility allows the design of highly available systems in more complex network environments, where firewalls might not be directly connected or where redundant links are required.

The critical point is that regardless of whether the interfaces are connected directly or through an intermediary device, the heartbeat signals must remain stable and reliable to ensure proper failover behavior. The use of a switch or router does not impact the core functionality of the HA system as long as the connection remains stable and does not introduce significant delay or packet loss.

Thus, Option A is correct because heartbeat interfaces in a hot standby configuration can be connected directly or through an intermediary device. Option B is incorrect because it fails to recognize the flexibility in the network design for HA configurations.

Question 8

By default, the domain ID of an OSPF process is the same as the process ID. You can use the domain-id command in the OSPF process view to change the domain ID.

A. True
B. False

Answer: B. False

Explanation:
Open Shortest Path First (OSPF) is a widely used link-state routing protocol that operates within an Autonomous System (AS). OSPF routers use process IDs to identify different OSPF processes running on a device. Each OSPF process can have its own routing table and configuration, and the process ID is used to distinguish between these different processes.

The domain ID in OSPF is an identifier used in OSPF Multi-Topology Routing (MTR) or OSPFv3 for IPv6 deployments. It provides the ability to run multiple independent OSPF instances or topologies on the same physical network infrastructure. The domain ID in OSPF is not the same as the process ID, and it is typically used for more advanced routing scenarios where multiple OSPF instances or topologies need to coexist on the same network.

By default, the domain ID of an OSPF process is not automatically the same as the process ID, and there is no domain-id command available in standard OSPF configurations. The process ID is locally significant and does not affect the OSPF domain ID. To change the domain ID in an OSPF configuration, you would use specific commands related to Multi-Topology Routing (MTR) or in specific OSPFv3 configurations, but this is not a default or common practice in standard OSPF configurations.

Thus, Option B is correct because the domain ID and process ID are not the same by default, and the domain-id command is not typically used in standard OSPF configurations. Option A is incorrect because it falsely claims that the domain ID is the same as the process ID by default, which is not accurate in standard OSPF configurations.

Question 9

In the DU label advertisement mode, if the liberal label retention mode is used, the device reserves labels received from all LDP peers regardless of whether the LDP peer is the optimal next hop for reaching the destination network.

A. True
B. False

Answer: A. True

Explanation:
Label Distribution Protocol (LDP) is a protocol used in Multiprotocol Label Switching (MPLS) networks to distribute labels between routers, allowing them to forward traffic based on labels rather than traditional IP routing. LDP works by establishing label mappings between routers, where each router advertises labels for the destinations it can reach.

In DU (Downstream Unicast) label advertisement mode, routers advertise labels for unicast destinations. These labels are essential for MPLS-based forwarding because they enable routers to forward packets using labels instead of performing a standard IP lookup.

The liberal label retention mode refers to a mode in LDP where a router retains all labels it receives, irrespective of whether the router is the best next-hop router for that particular destination. This mode essentially means that the router will accept and keep labels from all its LDP peers, even if those peers are not optimal in terms of forwarding traffic to the destination network.

In contrast, under more restrictive label retention modes, routers may choose to only accept labels from peers that provide the optimal forwarding path to a destination. However, the liberal label retention mode enables a more flexible and fault-tolerant approach, where the router does not discard labels from other peers, allowing for the possibility of faster rerouting in case of link failure or network changes.

The True option is correct because in the liberal label retention mode, a router does indeed keep labels from all peers, even those that are not the best next-hop for reaching the destination network. This can help with network resiliency and faster rerouting in dynamic environments.

Option B, False, is incorrect because it contradicts the behavior described in the question. In liberal label retention mode, the device will retain labels even from non-optimal LDP peers.

Question 10

In the Huawei SD-WAN Solution, after a CPE (Customer Premises Equipment) goes online, it automatically selects an RR (Region Route) without the help of iMaster NCE-WAN.

A. True
B. False

Answer: B. False

Explanation:
Huawei SD-WAN (Software-Defined Wide Area Network) is a solution designed to optimize the performance and management of wide area networks by leveraging software-defined technologies. The solution enables dynamic traffic routing across different links and simplifies network configuration and monitoring.

In Huawei's SD-WAN architecture, CPE (Customer Premises Equipment) refers to the devices or routers installed at the customer’s premises to connect to the SD-WAN network. These devices are responsible for routing traffic between the customer’s network and the SD-WAN backbone.

iMaster NCE-WAN is a central management system used in Huawei SD-WAN solutions. It plays a crucial role in controlling and managing the SD-WAN network. It provides functionalities such as policy management, configuration deployment, and real-time monitoring of the SD-WAN network’s health and performance.

One of the key components in the Huawei SD-WAN solution is the RR (Region Route). RRs are responsible for determining the best routes for traffic in different geographic regions, ensuring that the traffic is optimized and routed efficiently.

When a CPE device goes online, it does not independently select an RR. Instead, it requires the assistance of iMaster NCE-WAN to automatically select the appropriate RR. This ensures that the CPE device is able to make informed decisions about the best route for traffic, based on the policies and configurations deployed by the central controller (iMaster NCE-WAN). The controller coordinates the selection of RRs and ensures that traffic is routed based on the optimal conditions specified in the SD-WAN policies.

The False option is correct because, in Huawei’s SD-WAN solution, the CPE device does not automatically select an RR by itself. The process of selecting an RR is managed by the iMaster NCE-WAN, which provides the intelligence and control needed to ensure optimal routing decisions.

Option A, True, is incorrect because it suggests that the CPE device can independently select an RR without relying on the iMaster NCE-WAN, which is not how the solution is designed to work. The iMaster NCE-WAN plays a central role in the network management and decision-making process.