Huawei Updated H12-821_V1.0 Exam Questions and Answers by elis

Comprehensive and Detailed In-Depth Explanation:

A NET (Network Entity Title) consists of three parts:

Area Address → Identifies the IS-IS area.

System ID → Uniquely identifies the router.

SEL (NSEL - N-selector) → Always 0 in IS-IS.

The Area Address part contains:

AFI (Authority and Format Identifier) → Identifies the address type.

IDI (Initial Domain Identifier) → Identifies the routing domain.

System ID is NOT part of the Area Address , so the correct answers are B (AFI) and C (IDI) .

???? Reference: Huawei HCIA-Datacom Study Guide, IS-IS Addressing and NET Structure.

Comprehensive and Detailed Step-by-Step Explanation:

1. Features of Wi-Fi 6:

Wi-Fi 6 (802.11ax) introduces several new technologies to improve network efficiency, reduce latency, and optimize power usage:

OFDMA (Orthogonal Frequency Division Multiple Access): Allows multiple devices to transmit simultaneously, improving concurrency.

TWT (Target Wake Time): Reduces power consumption by scheduling communication times for devices.

High Bandwidth: Supports up to 9.6 Gbps, significantly faster than Wi-Fi 5.

2. Why Zero Latency is Incorrect:

While Wi-Fi 6 reduces latency compared to earlier standards, zero latency is not achievable due to inherent delays in network communication.

The statement " Realizes zero latency " is misleading and technically inaccurate.

3. Analysis of Each Option:

Option A: Uses OFDMA technology to achieve high concurrency.

Correct (True Statement).

OFDMA is a core feature of Wi-Fi 6 that improves concurrent communication.

Option B: Realizes zero latency, ensuring efficient service running.

Incorrect (False Statement).

Wi-Fi 6 reduces latency but cannot eliminate it entirely.

Option C: Provides high bandwidth, up to 9.6 Gbps.

Correct (True Statement).

Wi-Fi 6 supports a theoretical maximum bandwidth of 9.6 Gbps.

Option D: Uses TWT technology to reduce terminal power consumption.

Correct (True Statement).

TWT schedules communication times, allowing devices to enter low-power states and conserve battery life.

4. Summary:

The false statement is B , as Wi-Fi 6 does not achieve zero latency.

Explanation of VLAN Pool Assignment Algorithms:

In WLANs, VLAN pools help reduce broadcast domains and improve network performance by distributing users across multiple VLANs. Two algorithms are used for VLAN assignment:

Even Assignment Algorithm:

The number of users in each VLAN is even.

This algorithm assigns users evenly across VLANs, ensuring a balanced distribution of users in each VLAN.

When STAs go offline and online again, their VLANs and IP addresses may easily change.

Since the assignment is based on maintaining even distribution, a device (STA) may not be assigned the same VLAN when it reconnects, leading to potential IP address changes.

Hash Assignment Algorithm:

The number of users in each VLAN is uneven.

The hash algorithm assigns users to VLANs based on a hash value (e.g., derived from the MAC address). This may result in an uneven distribution of users across VLANs.

VLANs and IP addresses remain unchanged for STAs that go offline and online again.

The hash algorithm ensures that a device reconnects to the same VLAN, preserving its IP address.

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Comprehensive and Detailed in-depth Step-by-Step Explanation:

To understand this question, let ' s first review the functional planes in network devices, particularly Huawei switches:

Control Plane :

The control plane is responsible for generating and maintaining routing tables and forwarding entries.

It uses protocols like OSPF, BGP, and RIP to exchange routing information with other network devices. Once the routing information is processed, it installs forwarding entries into the forwarding plane for actual packet forwarding.

On Huawei switches, the control plane is mandatory for building and updating the forwarding table. Without it, the data plane cannot forward traffic correctly.

Forwarding Plane (or Data Plane) :

This plane handles the actual forwarding of packets based on the forwarding table created by the control plane.

The forwarding plane operates at high speed to ensure that traffic flows efficiently.

Monitoring Plane :

This plane is responsible for network management and monitoring. It gathers statistics and provides tools for troubleshooting and visibility.

In this case, the control plane provides the routing information and forwarding entries required for the data plane to perform packet forwarding. Therefore, the correct answer is B. Control plane.