H12-891_V1.0 Practice Exam Questions with Answers HCIE-Datacom V1.0 Certification

GRE (Generic Routing Encapsulation)supports encapsulation of many protocol types:

SupportsIPv4 and IPv6 unicastencapsulation —?

Doesnot support IPv6 broadcastencapsulation. GRE doesn’t natively handle multicast or broadcast IPv6 traffic well —?

It is a lightweight tunneling protocol and relativelyeasy to deploy, placing minimal overhead on devices —?

Correct answer: C. GRE can encapsulate IPv6 broadcast packets— is incorrect.

Comprehensive and Detailed Explanation:

Theregular expression100.s follows these rules:

100 matchesexactlythe sequence 100.

(dot) representsany single character(digit, letter, or symbol).

s specifically looks for the character s, but it isnot included in the given choices.

Now, analyzing each option:

?1000matches ? 1000 (fourth character matches . as a wildcard).

?100does not match ? No extra character after 100.

?10000does not match ? Too many extra characters.

?1001does not match ? s is not present.

Thus,1000 is the correct answer(C).

????Reference:Huawei HCIE Datacom Regex Guide - Regular Expressions in Networking

OSPFv3 Configuration Principles:

OSPFv3, the OSPF version supporting IPv6, differs from OSPFv2 in several aspects:

Interface-based Configuration:

OSPFv3 is configured on interfaces directly, unlike OSPFv2 which uses the network command.

Router ID:

The Router ID is still a 32-bit number, typically represented as an IPv4 address.

It must be explicitly specified since OSPFv3 requires a Router ID for operation, even though it supports IPv6.

Analysis:

A. [R1-GigabitEthernet0/0/1] ospfv3 1 area 0:

Correct. This command enables OSPFv3 process 1 on the GE0/0/1 interface in Area 0.

B. [R1-ospfv3-1] router-id 10.1.1.1:

Correct. This correctly sets the Router ID for OSPFv3 process 1.

C. [R1-ospfv3-1-area-0.0.0.0] network 2001:DB8:2345:12::1 ::

Incorrect. OSPFv3 does not use the network command as in OSPFv2. Instead, OSPFv3 is directly configured on interfaces.

D. [R1] router id 10.1.1.1:

Incorrect. The Router ID should be set within the OSPFv3 process view, not the global configuration view.

Therefore, the correct answers are A and B.

Comprehensive and Detailed In-Depth Explanation:

In theHuawei iMaster NCE-Campussolution, when using athird-party Portal authentication application, the following process occurs:

After the Wi-Fi user connects to the network, any attempt toaccess a website for the first timetriggersHTTP redirection.

The user isredirected to the login pageprovided by the third-party authentication application.

This mechanism ensures that the userauthenticatesbefore accessing external resources.

The redirection behavior is consistent withcaptive portal functionality, which is standard for user authentication on Wi-Fi networks.

Therefore, the statement isTRUE.

In OSPFv3 (used for IPv6), Link LSAs (Type 8) are not advertised throughout the entire area. Instead, they are only advertised on a specific link (i.e., the local link). This differs from OSPFv2, where LSAs like Type 1 or Type 2 are advertised across the area.

Exact Extract - Huawei HCIE-Datacom V1.0 Courseware - Chapter: OSPFv3 Operation

“Link LSAs are generated by routers for each attached link and sent only on that link, not flooded throughout the area.”

????Analyze the Configuration:

[R2] acl 2000

[R2-acl-basic-2000] rule deny

[R2] ospf

[R2-ospf-1] area 1

[R2-ospf-1-area-0.0.0.1] filter 2000 import

[R2-ospf-1-area-0.0.0.1] quit

[R2-ospf-1] default-route-advertise always

????Understanding Key Concepts:

Type 3 LSAs (Inter-Area Routes):

Generated by ABRs to advertisesummary routesbetween areas.

Filtering Type 3 LSAsis possible using import filters (like in Area 1).

Type 5 LSAs (External Routes):

Flooded only within the same ASbutdo not enter stub or NSSA areas.

?Breakdown of the Options:

A. Type 5 LSAs are flooded in Area 1??Incorrect

If Area 1 is astub or NSSA, thenType 5 LSAs are not allowed.

Although the diagram does not explicitly say Area 1 is a stub/NSSA,real deployments often use stub areas at the edge (like Area 1).

More importantly,the filter is applied to Area 1, and there isno redistributionof external routes into Area 1 in the config.

Therefore, Type 5 LSAs wouldnot be floodedthere.

B. Type 3 LSAs are not flooded in Area 1??Correct

The command filter 2000 import with ACL rule deny meansType 3 LSAs are filtered from Area 0 into Area 1.

C. Type 3 LSAs are not flooded in Area 2??Correct

There isno filter applied to Area 2, so thiscould be false,butsince the question asks for the incorrect statement, this is not the answer.

D. Type 5 LSAs are flooded in Area 2??Correct

Area 2 is not shown to be stub or NSSA, and there’s no filter or restriction configured.

Hence,Type 5 LSAs are allowedandflooded in Area 2.

?Correct Answer: A. Type 5 LSAs are flooded in Area 1.

Challenges of Static VXLAN Tunnel Configuration

Astatic VXLAN tunnelrequires manualVTEP-to-VTEP configuration, making it complex to maintain.

?A. Heavy configuration workload in a distributed gateway scenario

Static VXLAN requires manual configuration of VTEP mappings, making itdifficult to scale and adjustwhen adding new VTEPs.

?B. Remote MAC addresses are learned through data flooding

UnlikeBGP EVPN-based VXLAN, whichadvertises MAC/IP bindings through BGP,static VXLAN relies on flooding for MAC learning, causingexcessive traffic.

?D. N(N-1)/2 tunnels are required for full mesh connectivity

IfN devices need to communicate, each must be manually configured withN(N-1)/2 VXLAN tunnels, leading tohigh administrative overhead.

Incorrect Statement Explanation:

?C. Static VXLAN tunnels use protocols on the control plane, consuming device resources.

Wrong!Static VXLANdoes not use a control plane protocollike BGP EVPN.

Instead,it relies entirely on static mappings, reducing control plane usage.

Reference from Huawei HCIE-Datacom Documentation:

Huawei VXLAN Configuration Guide – Static vs. Dynamic VXLAN Tunnel Establishment

HCIE-Datacom Training Material – Manual Configuration Challenges in Static VXLAN

Understanding Inter-AS MPLS L3VPN Option C

????MPLS L3VPN provides Layer 3 VPN services over an MPLS backboneby using BGP to exchange VPN routes.

????Inter-AS MPLS L3VPN Option C (Carrier-to-Carrier Model) works as follows:

ASBRs (Autonomous System Boundary Routers) exchangeVPNv4 routes using MP-BGP.

ASBRsdo NOT store VPN routing tables. Instead, theyadvertise labeled IPv4 routesto enable inter-AS forwarding.

How ASBR-PE2 Enables Inter-AS Communication?

?VPNv4 Address Family (Answer A - Required)

Used to exchangeMPLS VPN routes between PE routers.

MP-BGP (Multiprotocol BGP) exchanges VPNv4 prefixesbetween ASBR-PE1 and ASBR-PE2.

?Unicast BGP Address Family (Answer D - Required)

Required to exchangeIPv4 labeled routesbetween ASBRs.

EnsuresMPLS label forwarding between AS100 and AS200.

?BGP-LS Address Family (Answer B - Not Required)

BGP-LS (BGP Link-State) is used for SDN controllersto learn topology information.

It isnot required for Inter-AS MPLS L3VPN.

?VPN Instance Unicast Address Family (Answer C - Not Required)

This is used forPE-CE communicationbut isnot required between ASBRs.

Why is the Answer A, D?

?VPNv4 routes enable inter-AS VPN communication.

?IPv4 unicast routes are required for ASBR-PE2 to forward packets across AS boundaries.

Real-World Application:

Service Provider Networks:Used incarrier-to-carrier MPLS VPN deployments.

Enterprise WAN Interconnection:Enablesmulti-AS MPLS VPN connectivityfor large enterprises.

?Reference:Huawei HCIE-Datacom Guide – Inter-AS MPLS L3VPN Option C (Carrier-to-Carrier Model)

In Huawei iMaster NCE-WAN controller active/standby deployment, to ensure seamless switchover and uninterrupted management and control channel communication, the following IPs must be configured consistently:

A. Southbound public IP addresses — Required for southbound communication from remote WAN devices via public networks.

C. Southbound private IP addresses — Used for devices accessing controllers over private links. Must remain unchanged between controllers.

D. Northbound IP addresses — For API and external system integration, ensuring upper-layer platforms don't need reconfiguration during switchover.

Internal interconnection addresses (B) are used for internal HA communication between controllers and do not need to be identical, hence not selected.

Exact Extract - Huawei HCIE-Datacom iMaster NCE-WAN Deployment Guide:

“To maintain service continuity, configure consistent southbound and northbound IP addresses across active and standby controllers. Internal interconnection addresses differ between nodes.”

Comprehensive and Detailed In-Depth Explanation:

In theinter-AS MPLS VPN Option Bsolution:

Option Bestablishes amulti-hop eBGPconnection between the ASBRs (ASBR-PE1 and ASBR-PE2) to exchangeVPNv4 routes.

In this setup, theASBRs exchange labeled VPNv4 routesviaMP-BGP(Multiprotocol BGP).

The command:

[ASBR-PE1-bgp-af-vpnv4] undo peer 10.0.34.4 enable

is used todisable VPNv4 route exchangebetween theASBR-PE1andASBR-PE2.

If this command is executed,ASBR-PE1willnot transmit VPNv4 routestoASBR-PE2, breaking theinter-AS VPN connectivity.

Therefore, the statement isFALSEbecauseASBR-PE1andASBR-PE2mustexchange VPNv4 routes to maintain connectivity between the VPN sites across different ASes.

In BGP4+ (used for IPv6 routing), the MP_REACH_NLRI attribute is used to advertise reachable routes. The Next Hop field must:

Contain a global unicast IPv6 address

Link-local addresses are not used in MP_REACH_NLRI because they are valid only on a local link and not suitable for inter-AS routing.

RFC 2545 (Multiprotocol Extensions for BGP-4) also states that the Next Hop must be a routable global address.

Therefore:

C. It must be a global unicast address — is correct.

The other options involving link-local addresses are incorrect.

Comprehensive and Detailed In-Depth Explanation:

InHuawei Open Programmability System (OPS), theURL structureis used to specify managed objects in a standardized way.

The URL path/ifm/interfaces/interfaceis used inNETCONF/YANG-based APIsto representinterface-related dataon a device.

This path allows users toquery, configure, or manage network interfacesthrough programmatic means.

TheIFM (Interface Management)model is commonly used for managing network interfaces, and this URL path correctly follows the convention.

Therefore, the statement isTRUE.

X = 0

Y = 0

Z = 1

Understanding MPLS Label Headers

????What is MPLS (Multiprotocol Label Switching)?

MPLS is ahigh-performance forwarding technologythat replacesIP lookups with label switching.

Packets are forwardedbased on labels instead of destination IP addresses.

MPLS labels are stacked when passing throughmultiple hops.

????MPLS Label Stack Structure

Each MPLS label hasfour fields:

Label– 20-bit identifier used for forwarding.

EXP (Experimental Bits / Traffic Class)– 3-bit field used forQoS (Quality of Service).

S (Bottom of Stack)– 1-bit flag that indicates whether this is thelast (bottom) label in the stack.

TTL (Time-To-Live)– 8-bit field to prevent loops.

Understanding the EXP Fields (X, Y, Z) in the Figure

The image shows a packet with three MPLS labels.

Each label has anEXP field (X, Y, Z) representing the QoS bits.

By default,MPLS EXP bits are copied from the top label to lower labels unless modified by QoS policies.

If no QoS policy modifies the EXP bits, they remain thedefault value of 0.

Thebottom label in the stack (Label 3) often has an EXP value of 1 to indicate specific QoS policies.

Why Are the Answers X = 0, Y = 0, Z = 1?

?X = 0 (Default EXP for Label 1, the top label in the stack).

?Y = 0 (EXP for Label 2, unchanged from the default value).

?Z = 1 (EXP for Label 3, indicating a QoS setting applied to the bottom label).

Real-World Application:

MPLS QoS (Quality of Service):EXP values determinepacket priorityinService Provider networks.

Traffic Engineering (TE):MPLS labels guide packets throughoptimized paths, ensuringlow-latency services.

Enterprise WAN Optimization:MPLS traffic is prioritized forcritical applications like VoIP, Video Conferencing, and Cloud Services.

?Reference:Huawei HCIE-Datacom Guide – MPLS Label Stack and QoS EXP Field Processing

Route Target (RT)is aBGP extended community attributeused inMPLS Layer 3 VPNs (L3VPNs)to control theimport and exportof VPN routes between differentVPN instances (VRFs).

Explanation of Correct Answers:

?A. Each VPN instance is associated with one or more pairs of VPN Target attributes, used to control VPN routing information advertisement and reception between sites.

Each VRF (VPN Routing and Forwarding instance) has an associated RTthat determines which routes areimported and exportedbetween VPNs.

RTs enableinter-VPN communicationwhile maintaining separation between VPN customers.

?B. Export Target and Import Target are independent of each other and support multiple values to implement flexible VPN routing information advertisement and reception control.

TheExport RTspecifies which routes should be advertised.

TheImport RTspecifies which routes should be accepted into a VRF.

These can beconfigured independentlyto control traffic flow between VPNs.

?C. RTs are classified into two types: Export Target and Import Target.

Export Target: Defineswhich VPN routes are advertised.

Import Target: Defineswhich VPN routes are accepted.

A VPN instance can have multiple RTsto allow flexibility.

?D. The RT value is advertised to neighbors through the BGP extended community attribute in Update messages.

RTs are carried in BGP UPDATE messagesas part of theBGP extended community attribute, enabling VPN route exchange between PEs.

Reference from Huawei HCIE-Datacom Documentation:

Huawei MPLS VPN Configuration Guide – Route Target (RT) Concepts

HCIE-Datacom Study Material – BGP Route Advertisement in MPLS VPNs

Telemetry Data Collection in Huawei Devices

Telemetry allowsreal-time streaming of network performance databased on predefinedsampling paths. Supported sampling paths include:

?A. Interface statistics

Monitors real-time traffic usage, errors, and packet loss on interfaces.

?C. CPU information

Tracks CPU utilization and performance metrics.

?D. Memory information

Monitors RAM usage and system memory consumption.

Incorrect Answer:

?B. Information about the optical module on an interface

Telemetry does not natively support direct optical module monitoring; instead, SNMP or CLI commands like display transceiver are used.

Reference from Huawei HCIE-Datacom Documentation:

Huawei Telemetry Configuration Guide – Supported Sampling Paths

HCIE-Datacom Study Material – Network Performance Monitoring with Telemetry

The provided Python code uses the requests.post() function to make an HTTP POST request to retrieve a token from iMaster NCE. The body is structured using the json={} parameter, which serializes the dictionary into JSON format. The proper content-type and accept headers are included.

Let's analyze each option:

? Option A is correct: The print(r.json()) is a valid method to display JSON response from the server.

? Option B is correct: The token URL is constructed correctly: https://139.9.213.72:18002/controller/v2/tokens.

? Option C is correct: The request body is clearly in JSON format, specified by the json={...} argument.

? Option D is incorrect: The HTTP method used is POST, not GET. The statement is false, making it the correct answer to select.

Huawei Official Documentation Reference:

“To obtain a token, the client sends a POST request to /controller/v2/tokens, including credentials in the request body in JSON format.”

(Source: Huawei iMaster NCE RESTful API Reference Guide – Authentication Section)

FEC (Forwarding Equivalence Class) in MPLS is a group of packets that are forwarded in the same manner. MPLS can classify packets into FECs based on factors such as:

Destination IP address

Source address

CoS (Class of Service)

Application type

However, Fragment Offset, which is part of the IP header used for IP fragmentation, is not used in FEC classification. Fragment offset is more relevant to how IP packets are reconstructed and not suitable or used as a classification standard for forwarding decisions in MPLS.

Exact Extract - Huawei HCIE-Datacom V1.0 MPLS Chapter:

“FEC classification may be based on various parameters including destination address, source address, and even CoS values. However, fragment offset is not used as an FEC criterion, as MPLS forwarding occurs before IP reassembly.”

Understanding Inter-AS MPLS VPN Option C (Solution 2)

In MPLS L3VPN Inter-AS Option C, the Route Reflectors (RRs) are used for VPN route distribution but do not participate in data forwarding. The traffic forwarding path is based on MPLS labels assigned at different routers.

Each data packet carries two MPLS labels:

Transport Label (T1) – Used for forwarding within the backbone.

VPN Label (V1) – Used for VPN route identification.

Breaking Down the Labels:

?VPN Label (V1) – Allocated by PE1 (Answer: C?)

V1 (Inner Label) is the VPN label assigned by the egress PE router (PE1).

This label ensures that when the packet reaches PE1, it knows how to forward the traffic to CE1 (192.168.1.1).

?Transport Label (T1) – Allocated by P2 (Answer: B?)

T1 (Outer Label) is the transport label assigned by P2 to forward the packet across the AS core.

This label ensures the packet reaches the next-hop router (ASBR-PE1 in AS100).

Why Are the Other Options Incorrect?

?A. "T1 is allocated by RR2" (Incorrect)

RR2 is used only for route reflection; it does not participate in label allocation or forwarding.

?D. "V1 is allocated by P2" (Incorrect)

P2 is an intermediate router and does not allocate VPN labels.

VPN labels are always assigned by the egress PE router (PE1 in AS100).

????Reference:Huawei HCIE Datacom – MPLS L3VPN Inter-AS Option C

InSRv6 (Segment Routing over IPv6),flavorsare extensions to standard SRv6 instructions that define how theSegment Routing Header (SRH)is handled at specific points:

PSP (Penultimate Segment Pop): Instructs thepenultimate nodeto remove the SRH before reaching the last node ??

USD (Ultimate Segment Decapsulation): Instructs thefinal segmenttoremove the SRH and IPv6 header, exposing the payload ??

PSD (Penultimate Segment Decapsulation): Instructs thepenultimate nodeto remove the SRH and deliver the payload ??

USP (Ultimate Segment Pop)isnot a standard flavorin Huawei SRv6 implementations ??

Correct answers: A, B, D

Comprehensive and Detailed Explanation:

?gRPC supports four types of RPCs:

Unary RPC? Client sendsonerequest, server respondsonce.

Server streaming RPC? Server sendsmultiple responses.

Client streaming RPC? Client sendsmultiple requests.

Bidirectional streaming RPC?Bothsides exchange multiple messages.

?Why B and C Are Incorrect:

?(B) Incorrect? The method rpc dataPublish(stream serviceArgs) returns(stream serviceArgs) {} violates gRPC syntax.

?(C) Incorrect? rpc stream LotsOfGreetings(HelloRequest) returns (HelloResponse) {} containsincorrect stream positioning.

????Reference:Huawei HCIE Datacom – gRPC API and Streaming Mechanisms

Static information collection and analysisrefers to gatheringnon-changing (static) parametersof the network devices. These parameters are mostlyconfiguration-relatedand do not fluctuate dynamically.

Explanation of Correct Options:

?A. Device types

Includes information about thehardware platform, model, and series of the device.

Example:Huawei NE40E, CE12800, or AR routers.

?C. License

Licenses define feature capabilities, such as MPLS, BGP, or security functions.

Licenses arestatic parametersbecause they do not change unless manually updated.

Incorrect Options:

?B. Interface types

Interface types (GigabitEthernet, FastEthernet, Serial, etc.)can changedepending on hardware or software configurations.

They arenot staticbecause interfaces can beadded or removed dynamically.

?D. Packet loss rate

Packet loss rate is a dynamic parameter, as it varies depending on network conditions, congestion, or faults.

It is used inperformance monitoringrather than static data collection.

Reference from Huawei HCIE-Datacom Documentation:

Huawei Network Management Best Practices – Static & Dynamic Data Collection

HCIE-Datacom Guide – Network Monitoring and Analysis

Huawei NCE-Campus Network Health Check Manual

Huawei Open Programmability System (OPS) is a programmable network architecture that uses RESTful APIs. In RESTful operations:

GET ? Retrieve data

PUT ? Configure/replace the value of a managed object

POST ? Create new resources or perform non-idempotent operations

PATCH ? Partially update a resource

When configuring or updating the value of a managed object (fully replacing it), PUT is the correct method.

Exact Extract – Huawei OPS and RESTful API Guide:

“The PUT method is used to configure the value of a managed object, replacing the entire object if it exists.”

Comprehensive and Detailed Explanation:

?HTTP Status Code 401 Unauthorizedindicates thatauthentication credentialswere either:

Missing(e.g., no API key or token).

Invalid(e.g., expired session, incorrect credentials).

?Error Code Breakdown:

?(D) "Unauthorized" (Correct)? Indicates the clientmust authenticate first.

?(A) "Service Unavailable" (503)? Used when theserver is down.

?(B) "Access Denied" (403)? Used when the clientlacks permissioneven after authentication.

?(C) "Not Found" (404)? Used when theresource does not exist.

????Reference:Huawei HCIE Datacom – iMaster NCE-Campus RESTful API Error Codes

Huawei’sNetwork Access Control (NAC)Portal authentication supports various identity authentication methods for user login via a web page. These include:

Username and password— standard method.

Passcode— one-time password or PIN.

SMS verification code— users receive a dynamic code via SMS for identity verification.

However:

MAC addressauthentication is used inMAC-based authentication, not Portal. MAC authentication allows a device to be authenticated using its MAC address without user interaction (i.e., not via a Portal page).

Correct answer: D. User’s MAC address

When port security is enabled and the maximum number of learned MAC addresses is reached, the switch can trigger multiple security actions depending on configuration:

Discard packets with unknown source MACs

Generate alarms

Shut down the port (set to error-down)

Do all the above combined (default behavior)

The most comprehensive and commonly configured behavior is error-down + alarm generation, which corresponds to Option D.

Exact Extract - Huawei HCIE-Datacom Switching Guide:

“When the MAC address limit is reached on a port with port security enabled, the system can generate alarms and set the port to error-down state based on security policies.”

Comprehensive and Detailed In-Depth Explanation:

1. Free Mobility in Huawei Campus Networks:

Free mobility allows users to move freely within a campus network while retaining their access rights and security policies. It leveragesiMaster NCE-Campusas the controller to simplify the deployment and management of user policies.

2. Role of the Administrator:

Administrators are responsible for defining high-level policies and security configurations. Specifically:

Define a Policy Control Matrix:

Administrators create a matrix that specifies how users from different security groups interact.

This matrix outlines access permissions and is a part of the policy planning phase.

Define Security Groups:

Administrators categorize users, devices, or endpoints intosecurity groupsbased on their roles or functions.

These groups form the basis for applying uniform policies within the network.

3. Role of iMaster NCE-Campus (Controller):

The controller handles the automatic delivery of configured policies and security settings to network devices.

Deliver IP-Security Group Entries:

Once the administrator defines the policies and groups,iMaster NCE-Campusautomaticallydistributes the IP-Security Group Binding entriesto the relevant network devices.

This ensures consistent policy enforcement across the campus.

4. Why This Mapping Is Correct:

Administrators define the structure and policies, while thecontroller (iMaster NCE-Campus)handles the implementation and distribution.

This division of responsibilities optimizes the network management process, reducing human error and ensuring that policies are consistently applied.

Understanding the Network Scenario:

R2 is the boundary router between OSPF and IS-IS.

OSPF and IS-IS do not automatically redistribute routes between each other.

R4's loopback (10.1.4.4/32) exists in the IS-IS domain.

To allow R1 (OSPF) to reach R4’s loopback, R2 must redistribute IS-IS routes into OSPF.

Why Option C Is Correct (?)

?default-route-advertise in OSPF on R2:

This advertises a default route into the OSPF domain, allowing OSPF routers (R1, R3) to forward unknown traffic to R2.

Since IS-IS routes are not automatically injected into OSPF, this ensures R1 can reach R4.

?IS-IS Already Has Routes to OSPF

IS-IS routers (R3, R4) already learn routes from OSPF via R2 (assuming route redistribution is properly configured).

No need to run default-route-advertise in IS-IS.

Why Other Options Are Incorrect (?)

?A. Run default-route-advertise in both OSPF and IS-IS views on R2

Unnecessary in IS-IS. The IS-IS domain already learns OSPF routes from R2 via redistribution.

Only OSPF needs a default route to forward unknown traffic to R2.

?B. No configuration is required

Incorrect, because OSPF does not automatically learn IS-IS routes.

A default route or redistribution is needed for R1 to reach R4.

?D. Run default-route-advertise only in the IS-IS view on R2

Incorrect, because IS-IS already has routing information from OSPF.

The issue is with OSPF not learning IS-IS routes, so the command needs to be in OSPF view.

????Reference:Huawei HCIE Datacom – OSPF and IS-IS Route Redistribution and Interoperability

Comprehensive and Detailed Explanation:

?SRv6 Locator and Segment Structure:

TheSRv6 Locatoris2001:DB8:ABCD::/64? This defines the segment routing namespace for this node.?

Dynamic Segment (SID)=32 bits? Defined dynamically per segment.?

Args Field=32 bits? Used for function arguments.?

?(B) Incorrect?Static segments are NOT explicitly defined as 32-bit fieldsin Huawei SRv6.

????Reference:Huawei HCIE Datacom – SRv6 Locator and SID Structure

InOSPFv3,Link-LSA (Type 8)is generated by a routerfor each of its interfacesto advertise:

Therouter's link-local addresson that interface.

TheIPv6 prefixesassociated with the interface.

Flags and options, such as router priority or loopback indicators.

From the output:

Link-LSA (Interface GigabitEthernet0/0/0)

Originating Router: 10.1.2.2

Link-Local Address: FE80::2E0:FCFF:FECD:4F79

Prefix: 2001:DB8:2345:23::/64

A. The link-local address of R2’s GE0/0/0 is FE80::2E0:FCFF:FECD:4F79? This matches the Link-Local Address field in the LSA.?

B. The IPv6 address prefix of R2’s GE0/0/0 is 2001:DB8:2345:23::/64? This matches the Prefix field in the LSA.?

C. This LSA indicates that R2 does not support external routes but can participate in IPv6 route calculation??Incorrect.

TheLink-LSAdoesnot provide any indicationabout external route capabilities.

It simply advertisesinterface-specific IPv6 and link-local info.

Whether R2 supports external routes depends onType 5 (External) or Type 7 (NSSA) LSAs, not Link-LSAs.

D. This LSA is generated by R2? The Originating Router: 10.1.2.2 is R2’s router ID, so this LSA is definitely generated by R2.?

Correct Answers:A, B, D

The Link-LSA in OSPFv3 contains:

The link-local address used by the originating router on the link.

A list of all IPv6 prefixes associated with the link.

Flags such as router priority and the Router-LSA options.

These LSAs are alwaysgenerated by the router itselfand arenot flooded beyond the link.

Understanding BFD (Bidirectional Forwarding Detection)

BFDis ahigh-speed fault detection protocolused to monitor link failures inmilliseconds.

It operates atLayer 2 (Data Link Layer) and Layer 3 (Network Layer)to providefast convergence.

Why Can BFD Detect Failures in Milliseconds?

Useslightweight control packetsthat are exchanged between routers.

Works withOSPF, IS-IS, BGP, and MPLSto trigger fast convergence.

Detection time = (Transmit Interval) × (Detect Multiplier)

Example: If the interval is3msand the multiplier is3, failure detection takes9ms.

Why is the Answer TRUE?

?BFD achieves millisecond-level detectionby sending rapid probe packets.

?Used in high-availability networkswhere link failures must be detected inreal-time.

Real-World Application

Service Provider Networks:BFD improves network resilience by detecting link failuresfaster than traditional routing timers.

Enterprise WANs:Used inSD-WANsto switch paths dynamically.

MPLS Fast Reroute (FRR):Works withMPLS Traffic Engineeringfor near-instantaneous failover.

?Reference:Huawei HCIE-Datacom Guide – BFD for Fast Link Failure Detection

Comprehensive and Detailed Explanation:

?BIER vs. PIM Multicast Routing:

BIER (Bit Index Explicit Replication)eliminates the need formulticast distribution trees (MDTs)by encodingreceiver information into the packet header.

PIM (Protocol Independent Multicast)requiresMDTs to manage multicast forwarding paths.

?Correct Statements:

?(A) BIER uses a Bitstring fieldin packet headers for forwarding.

?(B) PIM builds MDTsto define multicast paths.

?(C) BIER does NOT require MDTs, making it more scalable.

?(D) Incorrect? BIER does not require hop-by-hop join messages.

????Reference:Huawei HCIE Datacom – BIER and PIM Comparison

Understanding Huawei CloudCampus Access Control

Huawei’sCloudCampus solutionprovidescentralized authentication and policy managementviaiMaster NCE-Campus.

????Analysis of Each Option:

?A. iMaster NCE can function as an authentication server.

Correct:iMaster NCE includesAAA (Authentication, Authorization, and Accounting) capabilities, reducing dependency on external servers.

?B. Cloud APs support local Portal authentication.

Incorrect:HuaweiCloud APs do NOT support local Portal authentication.

Instead,Portal authentication is managed centrally by iMaster NCE, NOT by individual APs.

?C. iMaster NCE can function as a Portal relay device.

Correct:It can relay authentication requests to aRADIUS or AAA server.

?D. iMaster NCE can interconnect with a third-party RADIUS server.

Correct:It supports integration withexternal RADIUS authentication serversforenterprise authentication.

Real-World Application:

Used inWi-Fi 6 enterprise deploymentswhere centralizedauthentication, security, and policy enforcementare needed.

?Reference:Huawei HCIE-Datacom Guide – CloudCampus Authentication Architecture

On the2.4 GHzband, onlythree non-overlapping channelsexist:1, 6, and 11.

Inhigh-density WLAN scenarios, channels like1, 5, 9, and 13can be used withlower transmit powerto reduce co-channel interference — though they slightly overlap, they can work in dense deployments when managed properly.

On the5 GHzband, there are many non-overlapping channels. It’s recommended tostagger high and low channelsamong adjacent APs toavoid interference.

Correct answer: A. TRUE

To determine R3’s role (Level-1, Level-2, or Level-1-2) based on the provided output of the display ipv6 routing-table protocol isis command on R3, we need to analyze the IS-IS routing information and understand IS-IS hierarchy and behavior, particularly in the context of IPv6 routing. Let’s break it down step by step:

Understanding the IS-IS Levels and Hierarchy:

IS-IS (Intermediate System to Intermediate System) is a link-state routing protocol that supports a two-level hierarchy:

Level-1: Routers within the same area, responsible for intra-area routing. Level-1 routers only maintain routing information for their area and rely on Level-1-2 routers to reach other areas.

Level-2: Routers that form the backbone, connecting different areas for inter-area routing. Level-2 routers maintain routing information across areas.

Level-1-2: Routers that operate both at Level-1 (within their area) and Level-2 (to connect to other areas). These routers act as boundary routers between Level-1 areas and the Level-2 backbone.

A router’s role (Level-1, Level-2, or Level-1-2) determines which types of adjacencies it can form and what routing information it advertises or receives.

Analyzing the Output:

The output shows R3’s IPv6 routing table with routes learned via IS-IS, specifically:

Destination: 2082:EDFC:DDCC::B824:0/127, Protocol: ISIS-L1

This route is learned via IS-IS Level-1 (ISIS-L1), indicating that R3 has a Level-1 adjacency and is receiving or advertising routes within its area.

The next hop (FE80::2E0:FCFF:FE45:6A3E) and interface (GigabitEthernet0/0/0) suggest this route is intra-area.

Destination: 2082:EDFC:DDCC::B891:0/127, Protocol: ISIS-L2

This route is learned via IS-IS Level-2 (ISIS-L2), indicating that R3 has a Level-2 adjacency and is receiving or advertising routes for inter-area or backbone routing.

The next hop (FE80::2E0:FCFF:FE50:406F) and interface (GigabitEthernet0/0/1) suggest this route is for a different area or the backbone.

Both Level-1 and Level-2 routes are present in R3’s routing table, which provides critical insight into R3’s role.

Determining R3’s Role:

Level-1 Routers:

Level-1 routers only participate in Level-1 adjacencies and maintain routing information for their area. They do not have Level-2 routes or adjacencies unless connected to a Level-1-2 router. Since R3 has a Level-2 route (ISIS-L2), it cannot be exclusively a Level-1 router.

Level-2 Routers:

Level-2 routers focus on inter-area routing and typically do not maintain Level-1 routes unless they are also configured as Level-1-2. Since R3 has a Level-1 route (ISIS-L1), it cannot be exclusively a Level-2 router.

Level-1-2 Routers:

Level-1-2 routers operate both at Level-1 (for intra-area routing) and Level-2 (for inter-area routing). They can form adjacencies with both Level-1 and Level-2 neighbors and maintain both types of routes. The presence of both ISIS-L1 and ISIS-L2 routes in R3’s routing table indicates that R3 is participating in both Level-1 and Level-2 adjacencies, making it a Level-1-2 router.

Evaluating Each Option:

A. R3 must be a Level-2 device.

This is incorrect because R3 has ISIS-L1 routes, indicating it is also participating in Level-1 adjacencies, which Level-2-only devices do not do. Level-2 devices focus solely on inter-area routing and do not maintain Level-1 routes.

B. The device role of R3 cannot be determined.

This is incorrect because the presence of both ISIS-L1 and ISIS-L2 routes in the routing table clearly indicates R3’s role. The combination of Level-1 and Level-2 routes confirms R3 is a Level-1-2 router.

C. R3 must be a Level-1-2 device.

This is correct. The routing table shows both ISIS-L1 (Level-1) and ISIS-L2 (Level-2) routes, meaning R3 is operating as both a Level-1 and Level-2 router, which defines a Level-1-2 device.

D. R3 must be a Level-1 device.

This is incorrect because R3 has ISIS-L2 routes, indicating it is also participating in Level-2 adjacencies, which Level-1-only devices do not do. Level-1 devices only maintain intra-area routes and rely on Level-1-2 routers for inter-area reachability.

Additional Considerations:

The Flags: D in the output typically indicates a directly connected route or a route downloaded to the forwarding table, but it does not affect the determination of R3’s IS-IS level.

The preference (15) and cost (20) are standard for IS-IS routes and do not impact the level determination.

In Huawei’s IS-IS implementation, routers can be configured explicitly as Level-1, Level-2, or Level-1-2 using commands like isis level-1-2 under the IS-IS process. The presence of both Level-1 and Level-2 routes confirms R3’s configuration as Level-1-2.

Huawei HCIE-Datacom Context:

According to Huawei HCIE-Datacom documentation, IS-IS routers can operate at different levels, and the routing table’s protocol type (ISIS-L1 or ISIS-L2) indicates the level of adjacency. A router with both Level-1 and Level-2 routes is necessarily a Level-1-2 device, as it participates in both intra-area and inter-area routing.

The display ipv6 routing-table protocol isis command on Huawei devices shows routes learned via IS-IS, and the protocol type (L1 or L2) directly reflects the router’s role in the IS-IS hierarchy.

Conclusion:

Based on the presence of both ISIS-L1 and ISIS-L2 routes in R3’s IPv6 routing table, R3 must be a Level-1-2 device, as it is participating in both Level-1 (intra-area) and Level-2 (inter-area) adjacencies. Therefore, the correct answer is C.

References to Huawei HCIE-Datacom Documents:

Huawei HCIE-Datacom V1.0 Training Material, Chapter on IS-IS Configuration and Hierarchy.

Huawei NE Series Router Configuration Guide, IS-IS Section (Level-1, Level-2, and Level-1-2 Operations).

Huawei Technical Whitepaper on IS-IS Protocol, discussing IPv6 Routing and Level Determination.

Correct Matching of Authentication Methods:

1?802.1X authentication?PC (GE0/0/2 on SW3)

2?MAC address authentication?IP Phone (GE0/0/3 on SW3)

3??Portal authentication?Wireless Clients (Connected via SW2/AP)

Understanding Network Admission Control (NAC) Authentication Methods

????Network Admission Control (NAC)enforcessecurity policies before allowing devices onto the network.

????Different types of devices requiredifferent authentication methodsbased oncapabilities and security requirements.

Analysis of Each Authentication Type:

?1??802.1X Authentication (Used for PC on GE0/0/2 of SW3)

Best for devices that support user authentication (e.g., PCs, Laptops).

Requiressupplicant software (e.g., Windows or macOS built-in 802.1X client).

Providesstrong security using EAP (Extensible Authentication Protocol) over RADIUS.

?2??MAC Address Authentication (Used for IP Phone on GE0/0/3 of SW3)

Best for devices that do not support username/password authentication (e.g., IP Phones, IoT devices).

UsesMAC addresses as identity credentials.

Suitable forVoIP networks, industrial IoT, and surveillance cameras.

?3??Portal Authentication (Used for Wireless Clients on SW2/AP)

Best for guests or mobile users accessing Wi-Fi networks.

Redirects users to aweb-based login pagebefore granting access.

Used inpublic hotspots, campus Wi-Fi, and enterprise guest networks.

Why These Assignments Are Correct?

1??802.1X for PC:

PCs support 802.1X authentication via supplicants (EAP-MD5, PEAP, etc.).

Ensureshigh security by verifying user credentials.

2??MAC Address Authentication for IP Phone:

IP Phones lack a username/password interface, so authentication is done via MAC addresses.

Simplifies authentication while maintaining security.

3??Portal Authentication for Wireless Clients:

Wireless users do not use 802.1X authentication directly; instead, they are redirected to a web login page.

Common in enterprise guest Wi-Fi and public hotspots.

Real-World Application:

Enterprise NAC Deployment:Ensuresonly authorized users and devices access the corporate network.

Campus & Hotel Wi-Fi Security:UsesPortal Authentication for guests, 802.1X for employees, and MAC-based for VoIP.

?Reference:Huawei HCIE-Datacom Guide – NAC Authentication Methods & Best Practices

Comprehensive and Detailed Explanation:

TheOSPF error outputshows:

?Hello timer mismatch (1 error)?Hello intervals must match for adjacency formation(A)?

?No Netmask mismatch errors?Subnet masks are consistent, so option C is incorrect?

?No Extern option mismatch?No evidence of area type inconsistency (option D)?

?If area IDs were mismatched, adjacency would not form (option B is correct)?

Thus, the correct answers areA and B.

????Reference:Huawei HCIE Datacom – OSPF Troubleshooting

SR-MPLS leverages IGP (OSPF/IS-IS) extensions to advertise Segment IDs (SIDs) and can also integrate with TE (Traffic Engineering) for bandwidth reservation using RSVP-TE or SR-TE.

Exact Extract – Huawei SR-MPLS Configuration Guide:

“SR-MPLS uses extensions in IGP to distribute label bindings and, combined with traffic engineering, supports bandwidth assurance and high-bandwidth services.”

Comprehensive and Detailed In-Depth Explanation:

Telemetry in a narrow senserefers specifically to thedevice-side telemetryprocess, which includes the following key modules:

Data generation (A):The device collects and generates telemetry data, such as performance metrics or operational statistics.

Data push (B):The deviceactively pushes the collected datato the configured destination (such as a collector or management system) using a data streaming protocol.

Data source (C):The entity on the device that generates or provides themonitored data.

Data subscription (D)isnot part of the device-side telemetry; it is related to themanagement system side, where users subscribe to specific telemetry data streams.

Therefore, the correct answers areA, B, C.

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.

Huawei iMaster NCE-Campus as an Authentication Relay Agent

HuaweiiMaster NCE-Campuscan act as arelay agentfor authentication services, forwarding authentication requests between users and authentication servers (e.g., RADIUS, LDAP).

?B. User Authentication

Validates user credentialsbefore granting network access.

Supports802.1X, Portal, MAC, and RADIUS authentication.

?C. User Analysis

Analyzes user behavior and access patternsto optimize security and network policies.

?D. Marketing

Providescustomized authentication portalswithadvertisements and promotional messages.

Incorrect Answer:

?A. User Accounting–Accounting is handled by the authentication server (e.g., RADIUS), not the relay agent.

Reference from Huawei HCIE-Datacom Documentation:

Huawei iMaster NCE-Campus Authentication Guide – Relay Agent Functions

HCIE-Datacom Study Material – User Authentication and Analysis in CloudCampus

Comprehensive and Detailed In-Depth Explanation:

MACsec (Media Access Control Security)is a security protocol that provides securecommunication over Ethernet links. It operates at the MAC layer (Layer 2) and offers the following key security services:

Integrity Check (B):Ensures that data has not been tampered with during transmission.

User Data Encryption (C):Protects data confidentiality by encrypting the payload.

Data Source Authenticity Verification (D):Confirms that the data originates from a legitimate source by using security associations.

Controllability Check (A)is not a service provided by MACsec. The term "controllability" typically relates to network management and configuration control rather than data security. MACsec primarily focuses on protecting data integrity, confidentiality, and authenticity, rather than controlling network elements or configurations.

When Spanning Tree Protocol (STP) is not enabled on a network, loops can occur in Layer 2 Ethernet networks, leading to various network issues. STP is designed to prevent loops by blocking redundant paths, and its absence can cause broadcast storms, MAC address table instability, and resource exhaustion. Let’s analyze each option in the context of Huawei HCIE Datacom documentation and network behavior:

A. A loop alarm is generated on the LAN switch.

This option is incorrect. Huawei switches, as per HCIE Datacom standards, do not automatically generate a specific "loop alarm" unless configured with loop detection features (e.g., Huawei’s Loop Detection Protocol or similar mechanisms). Without STP or loop detection enabled, the switch may not explicitly generate an alarm for a loop; instead, it will exhibit symptoms like broadcast storms or flapping MAC entries. Therefore, this is not a direct symptom of an STP-less loop. Reference: Huawei HCIE Datacom V3.0 Training Materials, Section 4.2 – Spanning Tree Protocol and Loop Prevention.

B. CPU usage is too high.

This option is correct. When a loop occurs without STP, broadcast packets (and sometimes multicast or unknown unicast packets) circulate endlessly in the network. This leads to excessive processing by switches as they handle these packets, resulting in high CPU usage. Huawei switches, as described in HCIE Datacom documentation, can experience CPU overload due to continuous packet forwarding and processing in a looped environment. Reference: Huawei HCIE Datacom V3.0, Chapter 5 – Switch Performance and Loop Management.

C. MAC entries flap.

This option is correct. In a loop without STP, switches continuously receive frames from multiple ports, causing MAC address tables to update repeatedly as the same MAC address appears on different ports. This "flapping" of MAC entries destabilizes the network and can lead to incorrect frame forwarding. Huawei HCIE Datacom emphasizes MAC address table stability as a critical aspect affected by loops, as outlined in Section 4.3 – Ethernet Switching and Loop Mitigation. Reference: Huawei HCIE Datacom V3.0, Section 4.3.

D. Host receives a large number of broadcast packets.

This option is correct. A loop without STP causes broadcast packets to circulate indefinitely, creating a broadcast storm. Hosts connected to the network will receive an overwhelming number of these packets, potentially leading to performance degradation or even network timeouts. This is a well-documented symptom in Huawei HCIE Datacom training, specifically in discussions about loop prevention mechanisms. Reference: Huawei HCIE Datacom V3.0, Chapter 4 – Layer 2 Loop Prevention.

Thus, the correct symptoms of a loop occurring due to the absence of STP include high CPU usage, flapping MAC entries, and hosts receiving a large number of broadcast packets. Option A is incorrect as it requires specific loop detection configuration, which is not implied in the question.

BGP in Huawei SD-WAN

Huawei SD-WAN usesBGP (Border Gateway Protocol) as the primary routing protocolto exchange VPN routes between Customer Premises Equipment (CPEs) and the controller.

?Why BGP is Used in SD-WAN?

Scalability: BGP can handle a large number of VPN routes.

Policy-Based Routing: BGP allowstraffic engineering and policy controlacross SD-WAN tunnels.

Multiprotocol Support: Huawei SD-WAN usesMP-BGP to exchange IPv4, IPv6, and VPNv4 routes.

Understanding IPsec SA (Security Association) Establishment

????IPsec (IP Security) provides encrypted communicationover IP networks.

????Security Associations (SAs) define encryption, authentication, and key parameters for IPsec tunnels.

Two IPsec SA Modes:

1??Manual Mode:

All parameters (keys, encryption methods, authentication settings) must be manually configured.

Keys do not change automatically, making it less secure.

2??IKE (Internet Key Exchange) Auto-Negotiation Mode:

UsesIKE Phase 1 and Phase 2to automaticallynegotiate, generate, and exchange keys.

Keys are periodically refreshed, increasing security.

UsesDiffie-Hellman (DH) key exchangefor secure key generation.

Why is Answer D Incorrect?

?D. SAs established in both manual and IKE auto-negotiation modes can be dynamically updated.

Incorrect:Inmanual mode, the IPsec SA isstaticand does not support dynamic updates.

Correct behavior:OnlyIKE auto-negotiation modesupportsdynamic re-keying and SA updates.

?Reference:Huawei HCIE-Datacom Guide – IPsec SA Modes and IKE Negotiation

Huawei AR routers used as egress gateways in CloudCampus solutions support multiple onboarding and deployment methods, including:

DHCP Option 148-based auto-deployment

Web-based management

CLI-based deployment and configuration (also supported)

So, the statement is incorrect—CLI-based deployment is supported.

Exact Extract - Huawei CloudCampus AR Router Deployment Guide:

“AR series routers support multiple deployment methods including CLI, DHCP Option 148, and web-based registration.”

Comprehensive and Detailed In-Depth Explanation:

InOSPFv3, theAS-external-LSA (Type 5 LSA)is the only LSA type that can beflooded throughout the entire Autonomous System (AS). It is used to advertise external routes (routes redistributed from other routing protocols or static routes) into the OSPF domain.

B. Intra-Area-Prefix-LSA (Type 9):Used to advertise IPv6 prefixes within an OSPF area, not across the AS.

C. Link-LSA (Type 8):Advertises link-local addresses and options, only within the local link, not the entire AS.

D. Inter-Area-Prefix-LSA (Type 3 or Type 4):Advertises prefixes between OSPF areas but not throughout the entire AS.

OnlyAS-external-LSAs (Type 5)can be propagated across the whole OSPF AS, making them essential for exchanging routes learned from other routing protocols.

Comprehensive and Detailed In-Depth Explanation:

A. Correct:OPS can use themaintenance assistantto triggerPython scriptsperiodically or based on events.

B. Correct:OPS supportsautomatic deploymentusing Python scripts to download software and configuration files.

C. Incorrect:OPS doesnot inherently provide local storagefor temporarily saving execution results when the network is disconnected. This would require additional programming logic in the script itself, which is not a built-in feature of OPS.

D. Correct:OPS can run scripts toautomatically check device healthand report the status.

Therefore, the incorrect statement isC.

Comprehensive and Detailed In-Depth Explanation:

The diagram shows aWAN networkwhereSegment Routing (SR)is used in conjunction with theiMaster NCEcontroller. The network consists ofData Centers (DCs),Branches,Provider Edge (PE)routers, andRoute Reflectors (RR)withinAS 65600. Let's analyze each network technology and its placement in the scenario.

1. BGP-LS (Border Gateway Protocol - Link State):

Application Location:1 (PE to RR)

BGP-LS is used tocollect and distribute network topology informationfrom theIGP (Interior Gateway Protocol)domain.

It enables theiMaster NCE(controller) to learn about the network topology and SR information from PE routers.

The PE routers send theirlink-state informationto theRRusingBGP-LS.

Why Location 1:

The RR collects topology data from PEs and forwards it to the controller for path computation.

2. BGP (Border Gateway Protocol):

Application Location:2 (RR to iMaster NCE)

Standard BGP is used forroute distributionandnetwork connectivity.

The RR usesBGPto exchange route information with thecontroller(iMaster NCE).

Why Location 2:

TheRRaggregates routes and exchanges them with the iMaster NCE for centralized management.

3. MP-IBGP (Multiprotocol Internal BGP):

Application Location:3 (PE to PE)

MP-IBGP is used toexchange VPNv4 and VPNv6 routesbetween PE routers within thesame AS.

It allows PEs toadvertise VPN routesacross thebackbone network.

Why Location 3:

PEs need to communicate VPN-related information within the AS, ensuring end-to-end connectivity between DCs and branches.

4. BGP SR-Policy/PCEP (Path Computation Element Protocol):

Application Location:4 (iMaster NCE to PE)

BGP SR-Policy andPCEPare used by thecontrollertodistribute SR policiesto the PE routers.

TheiMaster NCEcalculates optimal paths and sends the SR policies to PEs viaBGP SR-PolicyorPCEP.

Why Location 4:

The controller programs theSegment Routing pathsdirectly to the PEs for optimal traffic engineering.

Why This Mapping Is Correct:

The mapping is based on theroles and functions of each protocolwithin theSR-based WAN architecture. The controller uses BGP-LS to learn topology, BGP for route reflection, MP-IBGP for VPN route exchange, and BGP SR-Policy/PCEP for path computation and distribution.

?A. encoding: indicates the character set encoding format. Currently, only UTF-8 encoding is supported.

UTF-8 is the default and only supported character encoding in NETCONF XML.

?B. /: indicates the end of the current tag.

In XML, closes an element, defining the end of a structure.

?C.

The

?D. ?>: indicates the end of an instruction.

Closes theXML declaration.

Reference from Huawei HCIE-Datacom Documentation:

Huawei NETCONF Development Guide – XML Formatting Rules

HCIE-Datacom Training Material – Understanding XML in Network Automation

Understanding HTTP/1.1 Response Headers

????What is an HTTP Response?

When a web server responds to an HTTP request, itsends an HTTP response message.

The response containsheaders, a status line, and a response body.

Elements of an HTTP Response Header:

?A. Status Code?Correct

Indicates the response status (e.g., 200 OK, 404 Not Found).

?B. Reason Phrase?Correct

Provides ahuman-readable explanationof the status code (e.g., OK, Not Found).

?C. Protocol Version?Correct

Specifieswhich HTTP version is being used(e.g., HTTP/1.1).

?D. Response Method?Incorrect

TheHTTP method (GET, POST, etc.) is part of the request, not the response.

?TI-LFA (Topology Independent Loop-Free Alternate)is an enhancedFast Reroute (FRR) mechanismused inSR-MPLSnetworks.

?How TI-LFA Works:

A virtual node is created, aggregating multiple route advertisements.

Backup paths are precomputedusingSegment Routing (SR) SIDs.

When a link failure occurs, traffic isrerouted in <50mswithout waiting forIGP convergence.

????Reference:Huawei HCIE Datacom – TI-LFA and SR-MPLS TE Protection

Dynamic VLAN Authorization in Huawei CloudCampus

Dynamic VLAN assignmentallows users to be placed into specific VLANsbased on authentication methods, ensuring security and network segmentation.

Correct Explanations:

?A. Wired users using 802.1X authentication receive VLAN assignments dynamically.

After authentication,the access control system (e.g., iMaster NCE-Campus)assigns VLANs dynamically.

?C. Wireless users using 802.1X authentication also receive VLAN assignments.

Similar to wired users,wireless 802.1X authentication allows dynamic VLAN assignmentvia the RADIUS server.

?D. Wired users using MAC authentication can receive VLAN assignments.

If a userdoes not support 802.1X, MAC authentication can still be used to assign VLANs dynamically.

Incorrect Statement Explanation:

?B. When wireless users pass Portal authentication, they join the authorization VLANs delivered to edge nodes.

Wrong!InPortal authentication, VLAN assignmentis not dynamically deliveredbecausePortal authentication typically applies access policies, not VLAN changes.

Dynamic VLAN assignment is mainly used with 802.1X or MAC authentication.

Reference from Huawei HCIE-Datacom Documentation:

Huawei CloudCampus Configuration Guide – Dynamic VLAN Assignment and Authentication

HCIE-Datacom Training Material – VLAN Authorization in Virtualized Campus Networks

Comprehensive and Detailed Explanation:

In the given configuration:

Traffic from PC1 (192.168.1.1)is classified byACL 2000.

Traffic is remarked with DSCP value 26(DSCP 26).

DSCP 26 corresponds to AF31, which maps to theAF3 queuein DiffServ QoS.

DiffServ QoS Queue Mapping:

EF (Expedited Forwarding)? DSCP 46

AF4 (Assured Forwarding Class 4)? DSCP 40-47

AF3 (Assured Forwarding Class 3)?DSCP 26-31?

AF2 (Assured Forwarding Class 2)? DSCP 18-23

SinceDSCP 26 falls within AF3, the packets enter theAF3 queue on R2.

????Reference:Huawei HCIE Datacom – QoS and DSCP Mapping

Network Slicing Using Channelized Sub-Interfaces and FlexE

Bothchannelized sub-interfacesandFlexE (Flexible Ethernet)are used fornetwork slicing, but they have differentapplication scenarios:

?A. Channelized sub-interface is recommended for interfaces with bandwidth < 50 Gbit/s.

Channelized sub-interfacessplit a physical interfaceinto multiple logical sub-interfaces.

Best for lower-bandwidth links (<50 Gbit/s).

?B. FlexE is recommended for 50GE and higher-rate interfaces.

FlexEdivides a high-bandwidth physical link(e.g.,100GE, 400GE) into multiple virtual slices.

Used in high-speed backbone and data center networks.

?C. Only FlexE-based network slicing can be deployed across OTN devices.

FlexE is compatible with Optical Transport Network (OTN)and can be used for long-haul slicing across OTN.

?D. Only channelized sub-interface-based network slicing can be deployed across MSTP devices.

Incorrect!While MSTP supports channelized interfaces,FlexE is not restricted to MSTP deployment.

Reference from Huawei HCIE-Datacom Documentation:

Huawei FlexE Technology Whitepaper – Network Slicing in Transport Networks

HCIE-Datacom Training Material – Channelized Sub-Interface and FlexE in Network Slicing

Understanding OSPF Neighbor States

OSPF (Open Shortest Path First) establishes neighbor relationships through several states:

1??Down:No Hello packets received.

2??Init:Routerreceives Hello packetsbutits own Router ID is missingin the received packets.

3??2-Way:Routerssee each other in Hello packets. (Stable state for non-DR/non-BDR routers).

4??ExStart:Routersstart exchanging LSAsbut may faceMTU mismatches.

5??Exchange:Routers sendDatabase Description (DBD) packetsto synchronize link-state databases.

6??Loading:Routers exchangeLink-State Requests (LSRs) & Updates (LSUs)to fully sync.

7??Full:Routers are fully synchronized.

Analysis of the Answer Choices

?A. For non-DR and non-BDR routers on an Ethernet link, the 2-Way state is acceptable.

Correct:Non-DR/Non-BDR routers remain in2-Way statesince they don’t need to form full adjacency.

?B. The Init state indicates that the router has received Hello packets from its neighbors, but the received Hello packets do not contain the OSPF RID of the receiving router.

Correct:If an OSPF router receives a Hello butdoes not see its own Router ID, it stays in theInit state.

?C. The ExStart state indicates that two neighbor routers have inconsistent MTUs or the same OSPF Router ID (RID).

Correct:If MTUs mismatch or RIDs conflict, theDBD exchange fails, causing routers to remain inExStart state.

?D. The Attempt state indicates that the router does not send unicast Hello packets to configured neighbors.

Incorrect:

InAttempt state, routerssend unicast Hello packetsto manually configured neighbors (common inNBMA networks).

If no Hello responses are received, they remain inAttempt state, but theyDO send Hellos.

Real-World Application

OSPF Troubleshooting:Identifying routers stuck inInit or ExStart statescan point toMTU mismatches or neighbor misconfigurations.

NBMA Networks (Frame Relay, DMVPN):Manually configured neighbors may stay inAttempt state if Hello packets are lost.

?Reference:Huawei HCIE-Datacom Study Guide – OSPF Neighbor States & Troubleshooting

Comprehensive and Detailed In-Depth Explanation:

By default, OSPF does not automatically associate a domain ID with a process ID. The concept of "domain ID" is primarily used when redistributing routes between OSPF and BGP, particularly in MPLS VPN scenarios. The domain ID in OSPF helps maintain loop prevention and correct route advertisement between different OSPF domains. You can manually configure the domain ID using the domain-id command within the OSPF process view, but it is not inherently set to the process ID.

Comprehensive and Detailed In-Depth Explanation:

To supportSR-MPLS (Segment Routing over MPLS),OSPFusesType 10 Opaque LSAsto advertiseSegment Routing (SR) capabilities and information.

Type 10 Opaque LSA (B): Used fordistributing application-specific informationwithin an OSPF area. In SR-MPLS, it carries theSID/Label mappingsand other SR-related information.

Type 7 NSSA External LSA (A):Used to advertise external routes within an NSSA, not related to SR-MPLS.

Type 1 Router LSA (C):Advertises the router’s interfaces and links but does not carry SR-specific information.

Type 2 Network LSA (D):Advertises the links of abroadcast or NBMA network, not used for SR-MPLS.

Therefore, the correct answer isB (Type 10 Opaque LSA), as it enables theadvertisement of SR information.

Let’s break this down step-by-step based on Huawei IS-IS VPN and multi-process behavior.

???? Configuration Summary:

Process 1: IS-IS for the global routing table

Process 2: IS-IS for VPN instance tt

Process 3: IS-IS for VPN instance rr

? Option C: Correct

Process 1 contains only global routing information.

The configuration of isis 1 does not include any vpn-instance keyword, meaning it is bound to the global routing table.

It does not interact with VPN routing tables unless explicitly configured with import/export mechanisms or route leaking (which is not shown here).

Huawei Datacom Reference:

“When an IS-IS process is not associated with a VPN instance, it belongs to the global routing table and only maintains global routes.”

(Source: HCIE-Datacom Study Guide v3.0 – Chapter: IS-IS for IPv4 and IPv6, Section: Multi-Instance Routing)

? Option D: Correct

Routing information of process 2 is isolated from that of process 3.

isis 2 is bound to VPN instance tt

isis 3 is bound to VPN instance rr

Each IS-IS process in Huawei VRF context maintains independent LSDBs and routing tables, and by default, they do not share routing information unless route leaking or redistribution is configured (which is not shown in the config).

Huawei Datacom Reference:

“IS-IS processes bound to different VPN instances operate independently and do not share routing information.”

(Source: HCIE-Datacom Study Guide v3.0 – Chapter: MPLS L3VPN with IS-IS)

InMPLS VPN, packets are forwarded usingtwo labels:

Outer label (Transport Label)– Used by the MPLS backbone for forwarding.

Inner label (VPN Label)– Used by theegress PEto identify the correct VPN instance.

Explanation of Correct Options:

?A. The egress PE sends the data packet to the correct VPN based on the inner label.

Theinner label is assigned by the egress PEand determines the final destination VPN instance.

?B. The penultimate hop removes the outer label before forwarding the data packet to a peer egress PE.

Penultimate Hop Popping (PHP)occurs when thesecond-to-last router(P router) removes the outer MPLS label before forwarding to theegress PE.

This reduces theprocessing overheadon the egress PE.

?D. The penultimate-hop device receives a packet with an outer label.

Theouter label is used to forward the packet across the MPLS backbone.

Before reaching the egress PE, thepenultimate router still has the outer labeland processes it.

Incorrect Option:

?C. The IP data packet received by the egress LSR is without labels.

This isincorrectbecause theinner label (VPN label) is still presentwhen the packet reaches the egress PE.

Only theouter labelis removed by PHP, not the inner VPN label.

Reference from Huawei HCIE-Datacom Documentation:

Huawei MPLS VPN Configuration Guide – Label Processing

HCIE-Datacom MPLS Traffic Engineering and PHP Mechanism

Huawei iMaster NCE-Campus MPLS VPN Implementation Guide

Understanding MPLS Label Retention Modes

In MPLS (Multiprotocol Label Switching), aLabel Switching Router (LSR)can operate in one of two label retention modes:

1??Liberal Label Retention Mode (LLRM)

Stores all labels receivedfrom neighbors, even if they are not immediately used.

Advantage:Fast convergenceduring link failures.

Disadvantage:Consumes more memory & label space.

2??Conservative Label Retention Mode (CLRM)

Only keeps labels for the best next-hop path.

Advantage:Saves memory & label space.

Disadvantage:Slower convergence when topology changes.

Why are C and D Correct?

?C. An LSR reserves all labels distributed by its neighbor.

Correct:InLiberal Mode, the routeraccepts and stores all labelsreceived, even for non-best paths.

?D. The liberal mode requires more memory and label space.

Correct:Since the routerkeeps all labels, it requireshigher memory & storage.

Why are A and B Incorrect?

?A. An LSR retains labels from a neighboring LSR only when the neighbor is its next hop.

Incorrect:This describesConservative Mode, not Liberal Mode.

?B. This label retention mode saves memory and label space.

Incorrect:Liberal Mode consumes more memory, not less.

Real-World Application

Liberal Mode is used in large-scale MPLS networks where fast failover is critical.

Conservative Mode is preferred in memory-constrained environments.

?Reference:Huawei HCIE-Datacom Study Guide – MPLS Label Retention Modes

The Loopback interface is not advertised by default in IS-IS, unless a specific command is used (like network entity with loopback settings or enabling it manually). In this case, the GE0/0/0 and GE0/0/1 interfaces are both UP, and have IS-IS L1/L2 enabled. These two interfaces qualify to advertise IS-IS routes.

Exact Extract - Huawei HCIE-Datacom V1.0 IS-IS Chapter

“By default, only physical interfaces in UP state and configured with IS-IS (L1, L2, or L1/L2) participate in IS-IS. Loopback interfaces must be explicitly advertised using route import policies.”

Comprehensive and Detailed In-Depth Explanation:

In BGP EVPN,Type 2routes (MAC/IP Advertisement routes) are used to advertise:

MAC addressesof endpoints.

ARP entries(MAC-to-IP bindings).

IRB (Integrated Routing and Bridging) routes, allowing the advertisement of both Layer 2 and Layer 3 reachability.

These routes are essential for enabling dynamic VXLAN tunnel establishment and seamless host mobility.

Type 1 (Ethernet Auto-Discovery):Used for multi-homing information.

Type 3 (Inclusive Multicast Ethernet Tag):Used for BUM (Broadcast, Unknown unicast, and Multicast) traffic.

Type 4 (Ethernet Segment):Used for identifying Ethernet segments in multi-homing scenarios.

IS-IS (Intermediate System to Intermediate System) protocolhas a limit on the size ofLink-State PDUs (LSPs).

Why Fragmentation?

LSPs contain routing and topology information.

If the LSPexceeds the maximum size, fragmentationallows the device to store and forward more routesby breaking them into smaller LSPs.

Key Point:IS-ISfragmentation is essentialin large-scale networks where routing tables grow beyond the default LSP size limit.

?Reference:Huawei HCIE-Datacom Guide - IS-IS Protocol and Route Scaling

Comprehensive and Detailed In-Depth Explanation:

The statementAis incorrect because enablingDHCP snooping in the VLAN viewonly takes effect on interfaces within that specific VLAN that have DHCP snooping configured. It doesnot automatically apply to all interfaces of the device. Each interface within the VLAN must individually be configured or marked as trusted/untrusted.

B:Correct, as DHCP snooping, when enabled globally without any additional specifications, defaults to processingDHCPv4messages.

C:Correct, as DHCP snooping can protect against DHCP spoofing attacks by marking interfaces astrustedoruntrusted.

D:Correct, enabling DHCP snooping on an interface means it will monitor all DHCP messages on that specific interface.

Option B is incorrect because it falsely states that EBGP cannot be configured on Spoke-PE or Spoke-CE if the Hub-CE and Hub-PE run IGP. In reality, EBGP can still be used between Spoke sites and PE devices, regardless of the protocol between the Hub PE and CE. EBGP is often used for PE-CE communication, including in Hub-and-Spoke architectures.

Exact Extract - Huawei HCIE-Datacom VPN Section:

“In Hub&Spoke deployments, EBGP can be deployed between Spoke-CE and Spoke-PE. The choice of routing protocol between Hub-CE and Hub-PE does not limit this.”

WRED (Weighted Random Early Detection)helpsprevent congestionby randomly discarding packetsbefore buffers are full.

Drop Probability Behavior:

Below lower threshold=0% drop(packets pass normally).

Between lower & upper threshold=Progressively increasing drop probability.

Above upper threshold=100% drop (probability = 1).

?Reference:Huawei HCIE-Datacom Guide - WRED Mechanism

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)

Comprehensive and Detailed Explanation:

?SRv6 (Segment Routing over IPv6)works byencoding a segment list in the IPv6 header.

?How SRv6 Works:

TheSegments Leftfield indicates theremaining segmentsin the path.

Eachendpoint node processes the next segmentand decrementsSegments Leftby 1.

TheIPv6 Destination Address (DA) is updatedto the next segment.

Thus, the statement isTRUE.

????Reference:Huawei HCIE Datacom – SRv6 Packet Forwarding

Comprehensive and Detailed Explanation:

?iMaster NCE-WANis thecentralized SD-WAN controllerthat:

Manages SD-WAN network devices(CPEs, routers).

Optimizes traffic steeringusing AI-driven policies.

Enables automation, security, and analytics.

Thus, the statement isTRUE.

????Reference:Huawei HCIE Datacom – SD-WAN Architecture

Huawei Switch Deployment Methods in CloudCampus

?A. DHCP Option 148– Used forautomatic device registrationin iMaster NCE-Campus.

?B. CLI (Command-Line Interface)– Traditionalmanual configuration methodusing the command-line interface.

?C. Web Interface–Web GUI-basedconfiguration for easy management.

?D. Huawei Registration Center–Cloud-based automatic registration and provisioningfor plug-and-play deployment.

Reference from Huawei HCIE-Datacom Documentation:

Huawei CloudCampus Deployment Guide – Device Onboarding Methods

HCIE-Datacom Training Material – Zero-Touch Deployment (ZTP) in CloudCampus

Understanding VXLAN and BGP EVPN Control Plane

VXLAN (Virtual eXtensible LAN)is anoverlay network technologythat enablesLayer 2 (L2) extension over an IP-based networkusingMAC-in-UDP encapsulation.

????Traditional VXLAN Flooding Issue:

Without BGP EVPN, VXLAN usesflood-and-learnbehavior for MAC address learning.

Broadcast, Unknown Unicast, and Multicast (BUM) trafficis flooded to all VTEPs, which is inefficient.

????How Does BGP EVPN Solve Flooding?

BGP EVPN (Ethernet VPN) replaces the flood-and-learn model with a distributed control plane.

MAC/IP bindings are advertised through BGP EVPN Type 2 routes, eliminating the need forflooding ARP requests.

VXLAN routers learn MAC addressesproactivelyinstead of relying on flooding.

Why is the Answer TRUE?

?BGP EVPN fully prevents ARP flooding by distributing MAC/IP bindings via control plane updates.

?VTEPs only send traffic to known destinations, reducing network congestion.

?BGP EVPN is the industry standard for large-scale data center and campus VXLAN deployments.

Real-World Application:

Data Centers:Avoids unnecessaryARP request floodingin large cloud networks.

Campus Networks:ReducesL2 broadcast storms, improving network efficiency.

Service Provider Networks:Enablesscalable multi-tenant VXLAN solutions.

?Reference:Huawei HCIE-Datacom Guide – VXLAN BGP EVPN Control Plane Architecture

Comprehensive and Detailed In-Depth Explanation:

NSR (Non-Stop Routing)andNSF (Non-Stop Forwarding)are high-availability mechanisms used to maintain network stability during routing process failures:

NSR (Non-Stop Routing):

Operates within thelocal router only.

Keeps routing information synchronized between theactive and standby processes.

Does not require collaboration from neighboring routers.

NSF (Non-Stop Forwarding):

Requires collaboration from neighboring routersthat support graceful restart.

The router undergoing failover relies on its neighbors tomaintain forwarding tableswhile control plane recovery takes place.

Neighboring routers must supportGR (Graceful Restart)for NSF to function correctly.

Therefore, the correct answer isBbecauseNSF requires neighboring router collaboration, whileNSR does not.

Understanding SR-MPLS Prefix and Adjacency Segments

????What Are Prefix Segments?

Globally uniquelabels assigned to network prefixes.

Advertised viaIGP (OSPF, IS-IS) with SRGB (Segment Routing Global Block).

????What Are Adjacency Segments?

Locally significant labelsassigned to direct router adjacencies.

Not globally visible—only used within a local router’sLFIB (Label Forwarding Information Base).

Why is the Answer FALSE?

?Prefix Segments are globally unique, but Adjacency Segments are only locally significant.

?Adjacency Segments are not distributed globally through IGP.

?Only Prefix Segments use globally advertised SRGB labels.

Real-World Application:

Segment Routing Traffic Engineering (SR-TE):Usesprefix segments for global routingandadjacency segments for local path steering.

5G Core Networks:UsesSR-MPLS with Prefix SIDs for scalable path selection.

?Reference:Huawei HCIE-Datacom Guide – SR-MPLS Prefix & Adjacency Segments

In Huawei'sSRv6 instruction namingsystem, each letter keyword represents a specific forwarding behavior:

X (Cross): Forwards packets viaspecified Layer 3 interfaces??

M (MAC): SearchesLayer 2 forwarding tableforbroadcast/multicast,not unicast??

V (VPN): Searches theVPN routing table (VRF)for forwarding ??

T (Table): Searches aspecific routing table (e.g., user-defined)??

Correct answers: A, C, D

Comprehensive and Detailed In-Depth Explanation:

In theCloudCampus public cloud scenario, when devices are deployed through theHuawei registration query center, there isno need to configure DHCP Option 148on the campus network’s DHCP server.

Theregistration query centerautomatically provides thecontroller IP addressto the devices during the registration process.

DHCP Option 148is typically used to provide theiMaster NCE-Campus addressin on-premises or private cloud scenarios.

In thepublic cloud scenario, the devices obtain this information directly from the Huawei cloud platform, makingOption 148 unnecessary.

HTTP/2 is a TCP-based protocol, not UDP-based. It runs on top of TCP port 443 (usually via TLS). The protocol enhances performance using multiplexing, header compression, and stream prioritization, but it still relies on TCP, unlike newer protocols like HTTP/3, which uses UDP and QUIC.

Exact Extract - Huawei Application Networking Fundamentals:

“HTTP/2 continues to use TCP as its transport layer, introducing improvements like multiplexing over a single TCP connection. UDP-based HTTP/3 is a separate protocol built on QUIC.”

Understanding SR-MPLS Label Calculation

SR-MPLS usesSegment Routing Global Block (SRGB)andPrefix SIDsto assign labels dynamically. TheMPLS labelfor a node’s loopback interface is calculated as follows:

MPLS Label=SRGB Base+Prefix SID Index

Where:

SRGB Base=20000(as given in the figure)

Prefix SID Index=30(configured for R3’s Loopback1)

Label Calculation:

20000+30=20030

Thus, theMPLS label corresponding to the loopback1 interface of R3 is 20030.

Why the Answer is 20030?

?The SRGB defines the base label range.

?Each router is assigned a unique Prefix SID index.

?The label is dynamically computed by adding the Prefix SID Index to the SRGB Base.

Why Other Numbers Are Incorrect?

?Any value outside the range 20000-21000

Would be incorrect because it must be withinR3’s SRGB range.

?Using the Prefix SID Index directly (30)

Incorrect becauseMPLS labels are not assigned directly using Prefix SIDs; they are computed using the SRGB.

????Reference:Huawei HCIE Datacom – SR-MPLS Label Calculation and SRGB

From theIS-IS error output, the key error is:

Mismatched Area Addr(L1): 13

This clearly indicates that thearea addresses are different, which prevents theLevel-1 adjacencyfrom forming.

Why is Option D Correct?

IS-IS Level-1 routers must have the same area IDto form an adjacency.

Since the log shows amismatched area address, the adjacency fails at Level-1.

If R3 and R4 wereLevel-2 routers, they could form an adjacencyeven with different area IDs.

Why Are the Other Options Incorrect?

?Option A:No authentication failure is reported.

?Option B:No "Mismatched Level" errors appear, so their levels are compatible.

?Option C:No "Bad Circuit Type" errors indicate mismatched circuit types.

Thus, the correct answer isD.

????Reference:Huawei HCIE Datacom – IS-IS Neighbor Troubleshooting

Huawei SD-WAN supports various intelligent traffic steering mechanismsto optimize link utilization andbalance network trafficacross multiple links.

?D. Traffic bandwidth-based traffic steering

This method ensures that traffic isdistributed across multiple links based on available bandwidth.

SD-WAN dynamically selects linksbased on their real-time bandwidth utilization,ensuring optimal performance and load balancing.

Understanding Huawei SD-WAN Tunneling Technologies

Huawei SD-WAN usessecure tunnelingto connect branches, data centers, and cloud services.

????Tunneling Technologies in SD-WAN:

?IPsec (Answer B)? Providessecure encrypted tunnelsover public or private networks.

?GRE over IPsec (Answer D)?Encapsulates traffic inside GRE, then encrypts with IPsec, enabling support for multicast and non-IP traffic.

?A. WLAN (Incorrect Choice)? WLAN is awireless technology, not a tunneling protocol.

?C. MPLS (Incorrect Choice)? MPLS is acore network transporttechnology but is not used to establish SD-WAN data channels directly.

Why are Answers B and D Correct?

?Huawei SD-WAN primarily uses IPsec for data encryption.

?GRE over IPsec is used when supporting multicast or dynamic routing protocols over tunnels.

?Reference:Huawei HCIE-Datacom Guide – SD-WAN Tunneling Mechanisms

VRRP (Virtual Router Redundancy Protocol) and Flapping

VRRP ensuresgateway redundancyby allowing multiple routers to work together as avirtual router.Flappingoccurs when themaster and backup routers frequently switch roles.

Causes of VRRP Flapping:

?A. Too small interval between Advertisement packet transmissions–Can cause flapping

If theAdvertisement interval is too short, frequent VRRP state changes can occur.

?C. Packet loss on an interface of the backup device–Can cause flapping

If thebackup router loses VRRP packets, it might assume themaster is downand initiate an election.

?D. Flapping on the link transmitting VRRP Advertisement packets–Can cause flapping

If the link used for VRRPexperiences instability, packets may be lost, triggering VRRP role changes.

Incorrect Answer Explanation:

?B. Inconsistent preemption delay settings – Does NOT cause VRRP flapping

Preemption delay only affectswhen a router takes over as masterafter recovering from a failure.

It doesnot directly cause flappingbecause the role change happens onlyafter a delay, preventing frequent transitions.

Reference from Huawei HCIE-Datacom Documentation:

Huawei VRRP Configuration Guide – Preventing VRRP Flapping

HCIE-Datacom Study Material – VRRP Timers and Stability

VXLAN Inter-Subnet Routing with Symmetric IRB

VXLAN supportsinter-subnet routingusingIntegrated Routing and Bridging (IRB). Insymmetric IRB, both ingress and egress VTEPs performLayer 3 forwardingto ensure efficient packet forwarding across subnets.

?A. Both the ingress VTEP and egress VTEP forward packets based on the Layer 3 forwarding table.

Insymmetric IRB, bothingress and egress VTEPs perform Layer 3 lookup and forwarding.

The ingressroutes packets before encapsulating them in VXLAN, and the egressperforms another Layer 3 lookup to determine final delivery.

?D. When VTEPs forward inter-subnet user communication packets, the VNI carried in the VXLAN header is the L3VNI.

L3VNI (Layer 3 VXLAN Network Identifier)is used forinter-subnet routingbetween VXLAN segments.

Understanding VXLAN and ARP Suppression in BGP EVPN

VXLAN (Virtual Extensible LAN) is used toextend Layer 2 networks over Layer 3 infrastructure.

VXLAN uses VTEPs (VXLAN Tunnel Endpoints) to encapsulate and forward Layer 2 traffic.

BGP EVPN (Ethernet VPN)is used forMAC/IP address learning and distributionacross VXLAN networks.

How ARP Request Forwarding Works in This Scenario?

1??ARP Broadcast Suppression Enabled (VXLAN Optimized Forwarding)

SinceARP broadcast suppressionis enabled onVTEP1, theARP request is not flooded.

Instead, VTEP1checks its EVPN learned databaseto findPC2’s MAC address (MAC C).

2??VTEP1 Encapsulates the ARP Request

VTEP1encapsulates the ARP request in a VXLAN packetand sends it toVTEP2.

Theoriginal ARP frame inside the VXLAN tunnel still has:

Source MAC:MAC A(PC1's MAC)

Destination MAC:MAC C(PC2's MAC, learned via EVPN)

3??VXLAN Outer Headers

Theouter VXLAN headeruses:

Source IP:1.1.1.1 (VTEP1)

Destination IP:2.2.2.2 (VTEP2)

VNI (VXLAN Network Identifier):200(BD 20)

4??VTEP2 Receives and Forwards the ARP Request

VTEP2 decapsulates the VXLAN packetand forwards theoriginal ARP requesttoPC2 (MAC C).

This ensures thatonly the intended receiver (PC2) gets the ARP request, preventing unnecessary broadcast flooding.

Why the Answer is MAC C?

?B. MAC C is Correct

Thedestination MAC of the inner data frameisPC2’s MAC (MAC C).

This is becauseVTEP1 forwards the ARP request directly to VTEP2, which then forwards it to PC2.

Why Other Answers Are Incorrect?

?A. MAC B (Incorrect)

MAC B is VTEP1’s MAC address, which is used in theouter VXLAN header, not in the inner Ethernet frame.

?C. MAC A (Incorrect)

MAC A is the source MACof the ARP request (PC1), not the destination.

?D. MAC D (Incorrect)

MAC D is not mentioned in the topology, so it is irrelevant.

????Reference:Huawei HCIE Datacom – VXLAN BGP EVPN and ARP Suppression

In YANG model syntax:

cpu-info can be a list node (?)

cpu-infos can be a container node (?)

The sampling path does follow the YANG model hierarchy (?)

However, the prefix huawei-debug: indicates the YANG module name, not an actual data node. Therefore, debug is not necessarily the top node in the YANG hierarchy — it is a node under the huawei-debug namespace/module.

Exact Extract – Huawei Telemetry and YANG Modeling Guide:

“The format : is used in telemetry to indicate paths. The actual top-level node may differ from the module name.”

Comprehensive and Detailed In-Depth Explanation:

The correct configuration is qos car inbound cir 50000 pir 100000.

CIR (Committed Information Rate):The guaranteed minimum bandwidth, set to 50 Mbit/s (50000 kbps).

PIR (Peak Information Rate):The maximum allowable bandwidth, set to 100 Mbit/s (100000 kbps).

This configuration ensures that during peak hours, the minimum guaranteed bandwidth is 50 Mbit/s, while during off-peak hours, the bandwidth can increase to a maximum of 100 Mbit/s. The settings align with the carrier's requirements for dynamic bandwidth allocation based on network load.

HuaweiSD-WAN establishes secure tunnels between SD-WAN edge devices (CPEs, AR routers, and controllers) using tunneling protocols.

?B. GRE over IPsec(Correct Answer)

GRE (Generic Routing Encapsulation) over IPsecisthe primary tunneling method used in Huawei SD-WAN.

GRE provides multi-protocol encapsulation, whileIPsec ensures encryption and security.

Used forsecure communication over public WAN links (e.g., the internet, LTE, MPLS, etc.).

HuaweiiMaster NCE-Campusprovidesopen APIsfor seamless integration with third-party applications and services. Each API serves a specific purpose in managingnetwork security, operations, analytics, and user interactions.

1. Authentication and authorization ? Third-party authentication API

This API is used to integrate third-party authentication systems, such as:

LDAP (Lightweight Directory Access Protocol)

RADIUS (Remote Authentication Dial-In User Service)

OAuth/OpenID authentication

It ensures secureuser identity verification, access control, and single sign-on (SSO)in CloudCampus networks.

2. Network O&M ? Infrastructure API

TheInfrastructure APIprovides tools fornetwork monitoring, diagnostics, and automated management.

It is used for:

Device status monitoring

Network topology visualization

Fault detection and real-time alerts

Performance optimization

3. LBS (Location-Based Services) ? LBS API

TheLBS APIenables applications to accesslocation datacollected by the network.

It is used for:

Tracking users or assets within a campus network

Heatmap generation and movement analytics

Geo-fencing and location-based policies

4. Crowd profiling ? VAS API

VAS (Value-Added Services) APIis designed foradvanced analytics and business intelligence.

It supports:

User behavior analytics

Demographic profiling

Marketing strategies based on network usage patterns

Reference from Huawei HCIE-Datacom Documentation:

HCIE-Datacom Training Guide – CloudCampus Solution

Huawei iMaster NCE-Campus API Documentation

Huawei CloudCampus Solution Whitepaper – Open API and Use Cases

The incorrect statement is Option C, which says “A site can only belong to only one VPN.” This is false because a single site can belong to multiple VPNs if needed. For example, in some enterprise designs, a site may be part of both the Finance VPN and the Management VPN by configuring multiple routing instances (VRFs) and policies accordingly.

Exact Extract - HCIE-Datacom VPN Technologies Chapter:

“A site may be associated with one or more VPNs, depending on business requirements. This is achieved through VRF and route-target configurations.”

PQ (Priority Queuing) ensures low-latency services like voice and video are prioritized.

WFQ (Weighted Fair Queuing) fairly allocates remaining bandwidth to services like FTP.

Option B provides a balanced approach: guarantees for voice/video via PQ, and fairness for FTP via WFQ.

Exact Extract - Huawei HCIE-Datacom QoS Module:

“Voice and video traffic should be handled by PQ to minimize delay and jitter. Non-critical services such as FTP should be placed in WFQ queues to ensure bandwidth fairness.”

Understanding 802.1X Authentication in Enterprise Networks

????What is 802.1X?

802.1X is a network access control (NAC) protocol that enforces authentication before allowing a device to connect to a LAN.

It usesEAP (Extensible Authentication Protocol)overRADIUSfor user verification.

Typically deployed incorporate and campus networksforsecure wired and wireless access.

????How Does 802.1X Work?

1??Client (Supplicant) ? Requests network access.

2??Switch (Authenticator) ? Forwards request to RADIUS server.

3??RADIUS Server ? Verifies credentials & grants access.

Mandatory Steps to Enable 802.1X on SW3

?A. Configure an AAA Scheme

Defines authentication, authorization, and accounting (AAA) methods.

Links802.1X authentication to the RADIUS server.

?B. Configure an Authentication Profile

Specifies how authentication is handled on the switch.

Associates802.1X authentication with an AAA scheme.

?C. Configure an Authentication Domain

Groups authentication policies for different user types.

MapsAAA scheme to user login requests.

?D. Configure an 802.1X Access Profile

Applies 802.1X authentication to specific switch ports (GE0/0/2 & GE0/0/3).

Ensures thatonly authenticated users can pass traffic.

Why Are All Four Steps Necessary?

?Each step plays a critical role in enabling 802.1X authentication and linking it to the RADIUS server.

?Without any one of these configurations, the 802.1X authentication process would fail.

Real-World Application:

Enterprise Wired Security:Ensures thatonly authenticated devicesaccess corporate networks.

University Campuses & Public Wi-Fi:Prevents unauthorized access tosecure LAN environments.

?Reference:Huawei HCIE-Datacom Guide – 802.1X Authentication & RADIUS Server Configuration