Free Practice Questions for Huawei H12-891_V1.0 Exam

Comprehensive and Detailed In-Depth Explanation:

In large- and medium-sized campus networks,Multi-mode authenticationis commonly used for PCs connected to IP phones. This is because multi-mode authentication allows:

Multiple authentication methods on the same interface,such as MAC address authentication for the IP phone and802.1X authentication for the PC.

This setup is ideal for scenarios where both devices share a single network port but require different authentication mechanisms.

MAC address authentication (A)and802.1X authentication (B)individually cannot accommodate both devices efficiently.

Portal authentication (D)is mainly used for guest access and is not practical for IP phone and PC connections.

TheDifferentiated Services (DiffServ) modelforQuality of Service (QoS)enables traffic management based on predefined priorities. This involvesclassifying, policing, queuing, and scheduling trafficto ensure efficient network resource utilization.

Breakdown of Each QoS Processing Step:

✅Step 1: Traffic Classification and Marking

Purpose:Identifies and marks packets based onQoS attributessuch asDSCP (Differentiated Services Code Point) or 802.1p priority bits.

Function:Assigns aQoS labelto packets for further processing.

Example:Packets carryingvoice traffic (EF - Expedited Forwarding)are marked forhigh-prioritytreatment.

✅Step 2: Traffic Policing (CAR - Committed Access Rate)

Purpose:Enforcesbandwidth limitson specific traffic flows to prevent excessive usage.

Function:Drops or re-marks packetsexceeding the assigned bandwidth threshold.

Example:If avideo stream exceeds 10 Mbps, excess packets may bedropped or re-marked.

✅Step 3: Congestion Management (Queuing and Scheduling)

Purpose:Managestraffic flow through queuesbased on assigned QoS levels.

Function:Places packets in appropriatepriority queues (e.g., Strict Priority, Weighted Fair Queuing - WFQ, CBWFQ).

Example:Voice packets are assigned tohigh-priority queuesforlow-latency forwarding.

✅Step 4: Congestion Avoidance

Purpose:Prevents networkbuffer overflows and excessive packet drops.

Function:Uses mechanisms likeWRED (Weighted Random Early Detection)to drop lower-priority packets before congestion occurs.

Example:If a queuereaches 80% capacity, WRED may droplow-priority packetsto maintain QoS.

✅Step 5: Traffic Shaping

Purpose:Smooths out traffic burststo maintain a consistenttransmission rate.

Function:Buffers and delays packetsto prevent excessive packet drops.

Example:Ifoutgoing traffic exceeds 50 Mbps, shaping ensures itdoes not exceedthis limit while maintaining steady flow.

Analyzing the Routing Table Output:

The command display ipv6 routing-table protocol isis showsall IPv6 routes learned via IS-IS.

The output shows"Summary Count: 6", meaning R1 hassix IS-IS IPv6 routes.

Explanation of Correct Answers:✅A. R1 has six IS-IS IPv6 routes.

The "Summary Count: 6" confirms thatsix IS-IS IPv6 routes existin R1's routing table.

✅C. IS-IS IPv6 must have been enabled on GigabitEthernet0/0/1 of R1.

Theinterface GigabitEthernet0/0/1is listed as thenext-hop, meaning IS-IS IPv6 must beenabled on that interface.

✅D. R1 is not a Level-1 device.

The protocol is listed as"ISIS-L2", indicating that R1 is anIS-IS Level-2 (backbone) router,not a Level-1 router.

Incorrect Answer Explanation:❌B. R1 does not have IS-IS IPv6 routes.

Wrong!The output clearlyshows six IS-IS IPv6 routes, proving this statement false.

Reference from Huawei HCIE-Datacom Documentation:

Huawei IPv6 Routing Protocols Guide – IS-IS for IPv6

HCIE-Datacom Routing & Switching Training – IS-IS L1 & L2 Operations

Huawei IS-IS Configuration Guide – IPv6 Route Management

Comprehensive and Detailed In-Depth Explanation:

Thetelemetry protocol stackis structured as follows:

Communication layer (A):Managesdata transmissionbetween the telemetry client (device) and the server.

Transport layer (B):Uses protocols such asgRPC, HTTP/2, or TCPto transmit telemetry data.

Data encoding layer (C):Encodes data using formats likeJSON, Protobuf, or XML.

TheData analysis layer (D)isnot part of the telemetry protocol stackitself.

Data analysis typically occursafter the data has been collected and receivedon the server or collector.

Telemetry focuses ondata collection, encoding, transport, and transmission, not on analysis.

Therefore, the correct answer isD.

Comprehensive and Detailed In-Depth Explanation:

In SR-MPLS, ifprefix SIDs conflict, the following principles are applied:

Prefix with a smaller value (numerically lower SID) wins.

If the prefix length is the same, the lower SID value is selected.

In this case:

Both1.1.1.1/32 2 (A)and1.1.1.1/32 1 (B)have the same prefix length.

SinceSID 1is numericallysmallerthanSID 2,B (1.1.1.1/32 1)is selected.

The other routes (C and D) have different prefixes and do not directly conflict.

Stateless Address Autoconfiguration (SLAAC)is an IPv6 mechanism where a host automatically configures its ownglobal unicast addresswithout requiring a DHCPv6 server.

IPv6 Address Format in SLAAC:

First 64 bits→Network Prefix(received from the router's RA message).

Last 64 bits→Interface Identifier(generated using EUI-64 or a randomly assigned value).

Why is the Prefix Always 64 Bits?

SLAAC requires a/64 prefixbecause the host needsthe lower 64 bitsto generate a unique address.

IPv6 Neighbor Discovery (ND) and Address Autoconfiguration are designed for a /64 subnet mask.

Reference from Huawei HCIE-Datacom Documentation:

Huawei IPv6 Configuration Guide – SLAAC Addressing and Prefix Allocation

HCIE-Datacom Training Material – IPv6 Stateless Address Autoconfiguration (SLAAC)

BGP routing policiesallow administrators to:

Control incoming and outgoing routes.

Filter routes based onprefix, AS-PATH, communities, MED, next hop, etc.

Apply route maps, prefix lists, or filter policies during:

Route advertisement

Route reception

Route import/export into local RIB or VPN instance

This is a fundamental capability of BGP and is widely used in production environments for traffic engineering, route filtering, and policy-based routing.

Correct answer: A. TRUE

Comprehensive and Detailed In-Depth Explanation:

During a network migration test, it is crucial not only to verify that the network itself is functioning correctly but also to ensure thatupper-layer application servicesare running properly on the newly migrated network. Migration testing aims to confirm that the transition has not disrupted service functionality.

Option A and C focus solely on network performance, which is necessary but insufficient.

Option B refers to command outputs, which are technical checks and do not guarantee service continuity.

Option D correctly identifies that successful migration is indicated byproper operation of upper-layer application services, as the primary purpose of a network is to support these applications.

Huawei Datacom Reference:

“In RESTful APIs, GET is used for reading data, POST for creation, PUT/PATCH for updates, and DELETE for deletion. PATCH allows partial updates while PUT replaces the entire resource.”

(Source: HCIE-Datacom V1.0 – OPS & NETCONF API Chapter)