Huawei H12-891_V1.0 HCIE-Datacom V1.0 Exam Practice Test

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

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

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.”

SSH Public Key Authentication

Inpublic key authentication mode, the SSH client must generate akey pair (public and private keys)before connecting to an SSH server.

✅C. ssh-keygen -t dsa (Correct Answer)

DSA (Digital Signature Algorithm) key generationfor SSH authentication.

Generates aprivate key (id_dsa)and apublic key (id_dsa.pub).

In theHuawei SD-WAN solution, LAN-side devices (such as CPEs and aggregation routers) usevarious routing protocolsto connect to Layer 3 networks and exchange routes dynamically. The supported protocols include:

✅A. IS-IS (Intermediate System to Intermediate System)

Alink-state protocoloften used in large enterprise networks forfast convergenceandscalability.

✅B. OSPF (Open Shortest Path First)

Awidely used dynamic routing protocolfor intra-domain (LAN) connectivity.

Commonly used in enterprise networkstoconnect SD-WAN edge routers to LAN networks.

✅C. BGP (Border Gateway Protocol)

BGP is primarily used forWAN and internet connectivity, but it can also be usedinside large enterprise networksfor LAN-side routing.

BGP enables inter-domain routing and policy-based route control.

✅D. RIP (Routing Information Protocol)

A legacy distance-vector protocolstill supported in some networks for basic LAN routing.

Less preferred due toslow convergence and hop-count limitations.

Reference from Huawei HCIE-Datacom Documentation:

Huawei SD-WAN Deployment Guide – LAN-Side Routing Protocols

HCIE-Datacom Training Material – Routing Configuration in SD-WAN

Understanding MPLS Forwarding Mechanism

MPLS (Multiprotocol Label Switching) is a high-performance forwarding mechanism that operates on two planes:

1️⃣Control Plane:

EstablishesLabel Switched Paths (LSPs)using protocols likeLDP (Label Distribution Protocol),RSVP-TE (Resource Reservation Protocol - Traffic Engineering), orBGP-LU (BGP Label Unicast).

Assignslabelsto packets based on routing policies.

2️⃣Data Plane (Forwarding Plane):

Uses aLabel Forwarding Information Base (LFIB)instead of traditional IP routing.

Packets areforwarded based on labels, not IP addresses.

Analysis of the Answer Choices

✅C. The system automatically assigns an ID to the upper-layer application that uses a tunnel. This ID is also called the tunnel ID.

Correct:MPLS assigns aTunnel IDto applications that utilize tunnels (e.g.,VPNs, MPLS-TE, or L2/L3 services).

This ID helpsdifferentiate between various tunnel applications, ensuring traffic follows the correct LSP.

❌A. After an IP packet enters an MPLS domain, the MPLS device forwards the packet based on FIB table queries.

Incorrect:MPLS routersdo NOT use the FIB (Forwarding Information Base)for forwarding once labels are assigned.

Instead, they useLFIB (Label Forwarding Information Base)to switch packets based on labels.

❌B. If the tunnel ID is 0x0, the MPLS forwarding process starts.

Incorrect:If theTunnel ID is 0x0, MPLSdoes NOT start; it means no label is assigned, and traditionalIP forwardingoccurs.

❌D. If the tunnel ID is not 0x0, the normal IP forwarding process starts.

Incorrect:If the Tunnel ID isnot0x0, MPLSforwards traffic using label switching, not IP forwarding.

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.

Infirewall hot standby (HRP - Hot Standby Routing Protocol) mode, certain data can be synchronized between the active and standby firewalls to ensure uninterrupted service.

Thefollowing data is backed up:

✅Server mapping table:Contains information about NAT mappings and other session mappings.

✅AAA user table (excluding the default user admin):Ensures that authenticated users do not need to re-authenticate in case of failover.

✅Session table:Ensures that existing connections remain active when switching to the standby firewall.

❌Dynamic MAC address table is NOT backed upbecause it is dynamically learned and not relevant to firewall session synchronization.

✅Reference:Huawei HCIE-Datacom Guide - Firewall HRP Synchronization

In MPLS (Multiprotocol Label Switching), Label Switching Routers (LSRs) handle packets based onFECs (Forwarding Equivalence Classes)and their positions in the label-switched path:

Ingress LSR:The entry point for labeled packets; it classifies packets into FECs and assigns the initial label.

Transit LSR:Intermediate routers that swap labels and forward packets along the LSP.

Egress LSR:The last router in the LSP that removes the label and forwards the packet normally.

An LSRcannotbeboth an ingress and a transit router for the same FEC, because an ingress LSR is defined as thestarting pointfor that specific FEC's LSP. If it’s the ingress, it means the labeled pathstarts there, so it can't be in themiddle (transit)of that same path.

Therefore, the statement isFALSE.

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:

Analyzing the output:

A. Key authentication is disabled for the tunnel:Correct. The output explicitly states"key disabled".

B. The destination IP address of the tunnel is 10.0.3.3:Correct. The output shows"destination 10.0.3.3".

C. The tunnel is a GRE tunnel:Correct. The output states"Tunnel protocol/transport GRE/IP".

D. Keepalive detection is enabled on the tunnel:Incorrect.The output clearly shows"keepalive disabled".

Therefore, the correct answer isDbecause the tunnel doesnot have keepalive enabled.

InHTTP status codes:

401 Unauthorized: The server has received the request butrequires authentication. This typically means:

No token or credentials were provided.

Credentials/token were incorrect or expired.

Other options:

403 (Access Denied)would mean correct credentials butinsufficient permissions.

404: Resource does not exist.

503: Service unavailable.

Correct answer: A. Unauthorized

Let’s analyze the scenario and each statement carefully based on OSPF path selection and BGP behavior in Huawei routers.

✅ Option A: The preferred path is R1–R3–R4.

According to the OSPF cost values:

R1–R3–R4: Cost = 1 + 1 = 2

R1–R2–R4: Cost = 2 + 2 = 4

OSPF chooses the lowest-cost path to reach a destination. Therefore, R1 will prefer the R1–R3–R4 path to reach 172.20.1.4/32.

Huawei Datacom Reference:

"OSPF selects routes based on the shortest path calculated using link costs. The router always selects the path with the lowest cost."

(Source: HCIE-Datacom Study Guide v3.0 – OSPF Path Selection, Chapter 5)

✅ Option B: If the stub router on-startup command is run on R3, packet loss occurs during the power-off process of R3 but no packet loss occurs during the startup process of R3.

When R3 is powered off, OSPF needs to reconverge, which causes temporary packet loss.

When R3 starts up, it will advertise itself as a stub router using the stub-router on-startup command. This tells OSPF not to use R3 as a transit path during the startup period, thus preventing traffic blackholing.

Huawei Datacom Reference:

"stub-router on-startup command prevents a newly started router from being used as a transit node by OSPF, allowing routing to remain stable during convergence."

(Source: HCIE-Datacom Study Guide v3.0 – OSPF Stub Router Functionality, Chapter 6.2)

❌ Option C: The preferred path is R1–R2–R4.

This is incorrect because the OSPF path cost via R2 is higher (4) than the cost via R3 (2).

❌ Option D: Packet loss occurs during both the power-off and startup processes of R3.

Incorrect. As explained above, when the stub-router on-startup command is used, packet loss is avoided during startup, but still occurs during power-off since the alternate path requires convergence.

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.

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.

MPLS Positioning in the TCP/IP Model

MPLS (Multiprotocol Label Switching) operatesbetween the Data Link Layer (Layer 2) and the Network Layer (Layer 3).

✅MPLS is protocol-independentand supports variousnetwork layer protocols (IPv4, IPv6, VPN, etc.)by using labels instead of traditional IP routing.

✅How MPLS Works:

MPLSassigns labels to packets, allowing fast forwarding based on the label rather than a routing table lookup.

SupportsLayer 3 VPNs (L3VPNs), Layer 2 VPNs (L2VPNs), and MPLS Traffic Engineering (MPLS-TE).

✅Why MPLS is Between Layer 2 and Layer 3?

MPLS adds a label between the Layer 2 (Ethernet, PPP) and Layer 3 (IP) headers, effectivelycreating a separate forwarding mechanism.

Label Switching Routers (LSRs) forward packets based on labels instead of IP addresses, reducing processing time.

Reference from Huawei HCIE-Datacom Documentation:

Huawei MPLS Technology Guide – MPLS Architecture and Label Switching

HCIE-Datacom Study Material – MPLS Positioning and Functionality in TCP/IP

Comprehensive and Detailed In-Depth Explanation:

TheHuawei SD-WAN Solutioninvolves four types of channels to ensure smooth and efficient network operation:

Management Channel (A):Used for managing and monitoring SD-WAN devices. It facilitates communication between theiMaster NCE-Campus controllerand SD-WAN devices.

Control Channel (B):Responsible for transmittingcontrol plane informationsuch as routing updates and protocol control messages.

Data Channel (C):Carries actualuser data trafficover the SD-WAN network.

Orchestration Channel (D):Used forservice orchestration, configuration delivery, and policy management.

All four channels work together to provide comprehensive network management, data transmission, and service orchestration in an SD-WAN environment.

Comprehensive and Detailed In-Depth Explanation:

1. Understanding SR-MPLS (Segment Routing with MPLS):

Segment Routing (SR)leverages MPLS labels to define paths through the network.

The labels representsegments(nodes or specific paths) rather than traditional LDP or RSVP-TE labels.

Thelabel stackdetermines the forwarding path through the network.

Top Label:Determines thenext hop.

Next Label:After label pop, it indicates thesubsequent hop.

2. Analyzing the Given Label Stack:

The label stack encapsulated byR1is as follows:

Layer2:2046

2013

2032

2024

2046

Layer3

Thetop label (2046)indicates that thenext-hop routerisR4.

AfterR4pops the top label, thenext label (2046)directs the packet toR6.

3. Forwarding Path Analysis:

Step 1:R1sends the packet toR2based on internal routing.

Step 2:R2forwards the packet directly toR4as dictated by the top label (2046).

Step 3:R4pops the top label (2046) and checks the next label (again2046), directing the packet toR6.

Step 4:R6receives the packet as the final destination.

4. Why Option B is Correct:

The pathR1-R2-R4-R6matches thelabel stack processingin SR-MPLS.

Thelabels indicate the shortest pathchosen by SR policies, which isR1 → R2 → R4 → R6.

TheSR-MPLS label stackefficiently guides the packet through the optimal path without complex signaling.

Why Other Options Are Incorrect:

Option A (R1-R2-R3-R5-R6):

This path does not match thelabel sequenceas the labels clearly indicate adirect path via R4, not throughR3 and R5.

Option C (R1-R3-R2-R4-R6):

This path is longer and unnecessary, as thelabel stackindicates a moredirect path via R2 and R4.

In Huawei’sFree Mobility solution:

Authentication Point (AP): Identifies users and associates them with aSecurity Group Tag (SGT)upon access.

Policy Enforcement Point (PEP): Enforces policiesbetween different security groups, such as allowing or denying traffic.

Key points:

Ais correct — The PEP enforces inter-group access based on defined policies.

Bis incorrect — AP and PEPcan be on separate devices, offering deployment flexibility.

Cis incorrect — Thepolicy enforcementhappens at thePEP, not the AP. AP's job is to authenticate and tag traffic.

Dis correct — AP and PEP can be deployed ondifferent devices.

Correct answers: A, D

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.

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

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 the Routing Table Entries on R4

0.0.0.0/0 (Default Route)is installedtwicein the routing table.

TheNextHopvalues for the default route:

10.1.24.1 (GigabitEthernet0/0/1)

10.1.34.1 (GigabitEthernet0/0/0)

Cost:Both routes have a metric (Cost) of10, meaning they areequal-cost routes.

Protocol:ISIS-L1 (Intermediate System to Intermediate System - Level 1) confirms these routes are coming fromIS-IS routing.

Flags:D (Dynamic) means these routes were dynamically learned via IS-IS.

Why is Option D Correct?

Since both routeshave the same cost (10), they are consideredequal-costdefault routes.

The routerwill use both routes in a load-sharingfashion.

The answeris NOT A(Four equal-cost routes) because there areonly twodefault routes, not four.

The answeris NOT B(One default route) because there aretwo default routesin the table.

The answeris NOT C(Two default routes with different costs) because both routes havethe same cost (10).

Real-World Application

Equal-Cost Multi-Path (ECMP):The router can performload balancingacross the two equal-cost paths.

Resilience & Redundancy:If one link fails, the other can take over without re-calculating the entire routing table.

✅Reference:Huawei HCIE-Datacom Study Guide – IS-IS Routing & ECMP Load Balancing

Comprehensive and Detailed In-Depth Explanation:

The regular expression100.$can be broken down as follows:

100:Matches the exact sequence of digits "100".

(dot): Representsany single character.

$:Indicates theend of the line.

Therefore, the pattern100.$matches anyfour-character sequencethat starts with "100" and ends withany single character.

1000 (A): Matches because it has four digits, starting with "100" and ending with "0".

1001 (B): Matches because it has four digits, starting with "100" and ending with "1".

10000 (C): Doesnot matchbecause it hasfive digits.

100 (D): Doesnot matchbecause it only hasthree digits.

SRv6 Instruction Naming Conventions

SRv6 (Segment Routing over IPv6)uses segment identifiers (SIDs) with specific functions, indicated byinstruction keywords:

✅A. T: Searches a specified routing table to forward packets.

T (Table Lookup)→ Performsa lookup in a specified routing tableand forwards packets accordingly.

❌B. M: Searches a Layer 2 forwarding table for unicast forwarding.

Incorrect!SRv6 does not use M for Layer 2 unicast forwarding.

✅C. V: Searches a VPN instance routing table to forward packets.

V (VPN Routing Table Lookup)→Performs a lookup in a VPN instance (VRF) tablefor forwarding.

✅D. X: Forwards packets through one or a group of specified Layer 3 interfaces.

X (Cross-connect forwarding)→Forwards packets via a specified Layer 3 interface or group of interfaces.

Reference from Huawei HCIE-Datacom Documentation:

Huawei SRv6 Configuration Guide – SRv6 SID Naming and Instruction Set

HCIE-Datacom Study Material – Segment Routing over IPv6 (SRv6) Functionality

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.

ForOSPF neighbors to reach Full state, they must exchangeLSAs (Link State Advertisements) properlyand synchronize their databases.

Possible Causes Preventing OSPF from Entering Full State:

✅A. A link works abnormally

If thephysical or Layer 2 linkis unstable,OSPF Hello packetsmay be lost, preventing the Full state.

✅B. The OSPF network types on both ends of the link are inconsistent

OSPF network types (Broadcast, P2P, NBMA, etc.) must matchon both ends.

Example: If one router isP2Pand the other isBroadcast, adjacency issues occur.

✅C. The router IDs of neighbors are the same

Router ID conflicts prevent OSPF adjacencies from forming.

Each router must have aunique Router ID.

✅D. The OSPF MTU values of interfaces on both ends of the link are different

If MTU settings do not match,OSPF Database Description (DD) packets may be dropped, preventing Full state.

Reference from Huawei HCIE-Datacom Documentation:

Huawei OSPF Configuration Guide – Troubleshooting OSPF Neighbor Issues

HCIE-Datacom Study Material – OSPF Adjacency and Route Synchronization

In IPsec, a symmetric encryption algorithm (e.g., AES) is used for encrypting data due to its speed. To securely exchange the symmetric key between peers, asymmetric encryption algorithms (like RSA) are used.

This method ensures:

High performance (due to fast symmetric encryption)

Secure key exchange (asymmetric protection)

Exact Extract - Huawei HCIE-Datacom Guide – IPsec Encryption:

“IPsec uses symmetric algorithms to encrypt data for performance and asymmetric algorithms to securely exchange symmetric keys during IKE negotiation.”

TheTime-To-Live (TTL) fieldin MPLS is essential forpreventing infinite loopsandenhancing security.

MPLS TTL Field Functionality:

It prevents packets fromcirculating indefinitelyin the MPLS network.

It allowstraceroute (tracert) to identify MPLS hopswhen TTL propagation is enabled.

Explanation of Correct Answers:✅B. The processing of IP TTL copy hides the LSR in an MPLS domain, improving security.

IfTTL propagation is disabled, MPLS routers do not decrease TTL, hidinginternal LSRsfrom traceroute, enhancing security.

✅C. MPLS provides two TTL processing modes:

Default Mode:The MPLS TTLcopies the IP TTL valuewhen an IP packet enters the MPLS network.

Uniform Mode:The ingress LERsets the MPLS TTL to 255, so it does not decrement.

✅D. MPLS encapsulation in frame mode supports the TTL field, while cell mode does not.

Frame Mode (Ethernet, PPP, etc.) supports TTL.

Cell Mode (ATM/MPLS) does not support TTL.

Incorrect Answer Explanation:❌A. If TTL copy is disabled, users can use the tracert function to view MPLS hops.

Wrong!If TTL propagation is disabled, tracertcannotsee LSRs inside the MPLS core network.

Reference from Huawei HCIE-Datacom Documentation:

Huawei MPLS Technology Guide – TTL Field & Loop Prevention

HCIE-Datacom MPLS VPN Configuration Guide – Traceroute in MPLS Networks

Comparison Between Paramiko (SSH) and Telnetlib (Telnet)

✅Paramiko (SSH) is more secure than Telnetlib (Telnet).

SSH (Secure Shell) encrypts login credentials and session datausing encryption protocols likeAES and RSA.

Telnet transmits data in plaintext, making it vulnerable to eavesdropping and man-in-the-middle attacks.

✅Why is Telnet Insecure?

No encryption→ Credentials (username/password) are sent in plaintext.

Easily interceptedby attackers using packet sniffers (e.g., Wireshark).

Correct Method for Secure Remote Login in Python:

UseParamiko for SSH-based secure automation.

Example of logging in withParamiko (SSH)in Python:

import paramiko

ssh = paramiko.SSHClient()

ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())

ssh.connect("192.168.1.1", username="admin", password="password")

stdin, stdout, stderr = ssh.exec_command("display version")

print(stdout.read().decode())

ssh.close()

Reference from Huawei HCIE-Datacom Documentation:

Huawei Security Best Practices – Avoiding Telnet and Using SSH for Secure Access

HCIE-Datacom Training Material – Network Automation with Python (Paramiko & Telnetlib)

When VLAN-based MAC address flapping detection is configured, the following actions can be taken:

Alarm sending (generates logs or SNMP traps)

MAC address blocking (blocks specific flapping MAC addresses)

Interface blocking (shuts down or disables the interface temporarily)

Traffic filtering, however, is not an action option directly supported as a response to MAC flapping. Traffic filtering is part of ACL or QoS, not a built-in flapping response.

Exact Extract - Huawei Switching Configuration Guide – MAC Address Management:

“Actions that can be configured upon detection of MAC address flapping include sending alarms, blocking MAC addresses, and blocking interfaces. Traffic filtering is not supported as a direct action.”

BGP EVPN Type 2 Route (MAC/IP Advertisement Route)

This route carriesMAC and IP address bindingsto inform remote VTEPs about locally learned endpoints.

Why Use arp collect host enable?

Collects ARP entriesof locally connected hosts.

EnablesBGP EVPN Type 2 route generationto distribute the learned ARP information.

Incorrect Answer Explanations:❌A. mac-address xxxx-xxxx-xxxx– Manually configures a MAC address butdoes not enable ARP collection for EVPN Type 2 routes.❌B. arp-proxy enable– Enables ARP Proxy butdoes not advertise ARP information using BGP EVPN.❌D. arp distribute-gateway enable– Used inDistributed Anycast Gateway (DAG) modebutnot for collecting host ARP data.

Reference from Huawei HCIE-Datacom Documentation:

Huawei VXLAN EVPN Configuration Guide – ARP Handling and EVPN Type 2 Routes

HCIE-Datacom Training Material – VTEP ARP Advertisement in VXLAN Networks

The Protocol Trace function of iMaster NCE-CampusInsight allows O&M teams to analyze the full packet exchange process (e.g., DHCP, authentication, IP acquisition) between clients and the network. In this scenario, it helped pinpoint DHCP address pool exhaustion as the cause.

Exact Extract - Huawei iMaster NCE-CampusInsight Product Documentation:

“The Protocol Trace function visualizes packet-level interaction processes for DHCP, ARP, 802.1X, and others, allowing fast identification of root causes for network access issues.”

Comprehensive and Detailed In-Depth Explanation:

1. Understanding VXLAN Asymmetric IRB Forwarding:

InVXLAN (Virtual Extensible LAN)networks, there are two types of IRB forwarding:Symmetric IRBandAsymmetric IRB.

InAsymmetric IRB, routing occurs only at the ingress VTEP (Virtual Tunnel Endpoint).

Theingress VTEP (VTEP1)encapsulates the original data frame and sends it to theegress VTEP (VTEP2)over the VXLAN tunnel.

Thedestination MAC addressof the original Ethernet frame is theMAC address of the Layer 3 gateway (VBDIF)at the egress VTEP.

2. Analyzing the Topology:

PC1 (172.16.2.1/24) withMAC Ais sending traffic to PC2 (172.16.1.2/24) withMAC D.

Both PCs are in different subnets, so inter-subnet routing is required.

VTEP1 (1.1.1.1)on SW1 is the ingress VTEP.

VTEP2 (2.2.2.2)on SW2 is the egress VTEP.

TheVXLAN Network Identifier (VNI)for the traffic is100.

SW1 has two VBDIF interfaces:

VBDIF10 (MAC B)- Interface for BD10 (172.16.2.254).

VBDIF20 (MAC C)- Interface for BD20 (172.16.1.254).

3. Packet Flow in Asymmetric IRB:

Step 1:PC1 sends a packet destined for PC2. The packet is routed at theingress VTEP (SW1)using theVBDIF interface (VBDIF10 with MAC B).

Step 2:Theingress VTEP (SW1)encapsulates the packet in aVXLAN header(VNI 100) and sends it toVTEP2.

Step 3:Theoriginal data frame inside the VXLAN packetmust have adestination MAC addressthat matches thegateway MAC address (VBDIF20 - MAC C)at theegress VTEP (SW2).

Step 4:On reachingVTEP2, the encapsulation is removed, and the original frame withdestination MAC Cis forwarded.

Step 5:VTEP2performs Layer 3 routing to forward the packet toPC2.

4. Why MAC C is Correct:

Inasymmetric IRB forwarding, the routing decision at the ingress VTEP ensures that thedestination MACin the original frame is set to theVBDIF (gateway) MAC of the egress VTEP.

Since theegress VTEP (SW2)hasVBDIF20 (MAC C)for the destination subnet (172.16.1.0/24), thedestination MAC addressof the original frame isMAC C.

Comprehensive and Detailed In-Depth Explanation:

InNETCONF (Network Configuration Protocol), the operation can includeoperation attributesto specify how configuration data is handled:

merge (B):Merges the new configuration with the existing one.

replace:Replaces the existing configuration with the new one.

create (C):Creates a new configuration node, but will fail if the node already exists.

delete:Deletes an existing configuration node.

remove (A):Removes an existing node, but if the node does not exist, it will not generate an error.

The attribute"update" (D)isnot a valid NETCONF operation attribute.

Dis the correct answer as it does not exist within theNETCONF operation attribute set.

VXLAN tunnel configuration, you donot use a control planelike BGP EVPN. Instead, youmanually configureall necessary forwarding parameters, including:VNI (VXLAN Network Identifier): Identifies the VXLAN segment.VTEP IP Address: The remote tunnel endpoint.Ingress Replication List: Required for multicast emulation (flooding/BUM traffic) in the absence of a multicast control plane.Whenconfiguring statically, theVNIis essential to map Layer 2/3 services to the correct VXLAN segment.Thus, the correct word to complete the sentence is:VNICorrect answer: VNI

Why is Free Mobility Not Based on VLANs or IP Addresses?

Free mobilityin Huawei CloudCampus implementspolicy-based user access controlbased onuser identity (rather than VLANs or IP addresses).

Users canmove across different network locationswhile maintaining their assignedsecurity and access policies.

✅How Free Mobility Works:

Policies are applied based onUser Groupsinstead of VLAN or IP.

UsesGroup-Based Policy Control (GBP)andSoftware-Defined Access (SDA)principles.

❌Incorrect Statement Explanation:

Traditional networks rely on VLANs and IP addresses for segmentation, butFree Mobility applies policies at the user level, allowing seamless access anywhere on the network.

Reference from Huawei HCIE-Datacom Documentation:

Huawei CloudCampus Solution Guide – Free Mobility and Policy Control

HCIE-Datacom Training Material – Identity-Based Networking

IS-IS Multi-Process:

Huawei devices support runningmultiple IS-IS processes simultaneously.

These processes arecompletely independentof one another: different LSDBs, interfaces, routing tables, etc.

Each process can be associated with aseparate VPN instance, and asingle VPN instance can be served by multiple IS-IS processes.

IS-IS Multi-Instance:

One IS-IS process canrun multiple instances, typically used formulti-VPN scenarios.

However, Huawei's current implementation prefersone VPN per processfor clarity and control.

Based on Huawei’s design:

Ais incorrect — an IS-IS processcanserve multiple VPNs in other vendors, but Huawei typically uses one process per VPN for clean separation.

Bis correct — a VPN instance can be associated withmultiple IS-IS processes.

Cis incorrect in Huawei implementation context.

Dis correct —IS-IS processes are independent.

Correct answers: B, D

In Huawei’sCloudCampus Solution, VNs (Virtual Networks) areisolated by defaultfor security purposes. To enableinter-VN communication, you must explicitly configure policies that allow traffic between different VNs.

The correct way to control and enable this communication is viarouting policies, especiallyinter-VN routing policieson thecore or border nodes.

Static routesorOSPF deploymentsare not sufficient or appropriate for policy-controlled VN communication in this context.

Correct answer: D. Deploy a routing policy

SSH (Secure Shell) is a protocol designed for secure remote access and is always built on TCP, typically on port 22. UDP is not supported for SSH, as it is connectionless and doesn't provide the required reliability and order.

Exact Extract – Huawei Security Protocol Fundamentals:

“SSH is a TCP-based protocol. It does not support UDP. TCP ensures session reliability and data integrity, which are critical for SSH.”

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

VXLAN networkssuffer from ARP floodingbecause ARP requests arebroadcasted across all VTEPsin a Layer 2 domain. Toreduce ARP flooding, the following mechanisms can be enabled:

✅A. Local Proxy ARP

Allows the local VTEP to respond to ARP requests without forwarding them across the VXLAN network.

The VTEPcaches MAC-IP mappingsand replies directly to ARP requests, reducing unnecessary flooding.

✅B. ARP Broadcast Suppression

Converts ARP broadcast packets into unicast or multicast packetsto minimize network-wide flooding.

✅C. Host Information Collection

Collects and stores MAC-IP bindings of endpoints, which can be used by proxy ARP to reduce flooding.

Incorrect Answer:

❌D. Port Isolation

Port isolation prevents communication between devices within the same VLANbut doesnot help reduce ARP floodingbetween VTEPs.

Reference from Huawei HCIE-Datacom Documentation:

Huawei VXLAN Configuration Guide – ARP Optimization Techniques

HCIE-Datacom Training Material – Reducing ARP Broadcasts in VXLAN Networks

Huawei IPsec supports multiple modes for establishing Security Associations (SAs):

A. Template negotiation — Used in IPsec policy templates and dynamic VPNs.

B. IKE auto-negotiation mode — Automatically negotiates parameters via IKE Phase 1/2.

C. Certificate negotiation — IPsec peers can authenticate each other using certificates during IKE negotiation.

D. Manual mode — Static IPsec SAs can be manually configured without IKE, often used in simple or static topologies.

Exact Extract - Huawei Security Configuration Guide (USG Series):

“IPsec SAs can be established manually or dynamically through IKE, including using PSKs or certificates. Template-based approaches simplify large-scale deployment.”

In OSPF-based SR-MPLS TE, Adjacency Segment Identifiers (Adj-SIDs) are locally assigned by each router for its directly connected interfaces. These labels are allocated from the Segment Routing Local Block (SRLB) configured on the router. By default, Huawei routers use an SRLB range starting at 9000, and Adj-SIDs are assigned sequentially (e.g., 9000, 9001, 9002, etc.) to each adjacency.

For P3, adjacency labels correspond to its outgoing interfaces. Assuming P3 has two adjacencies (e.g., to P2 and P4, as inferred from typical network topologies), it will allocate two unique Adj-SIDs from its SRLB. Based on Huawei’s implementation:

The first adjacency (e.g., to P2) is assigned the next available label in the SRLB (e.g., 9002).

The second adjacency (e.g., to P4) is assigned the subsequent label (e.g., 9003).

Analysis of Options:

Option B (9002): Likely assigned to P3’s first adjacency (e.g., link to P2).

Option C (9003): Likely assigned to P3’s second adjacency (e.g., link to P4).

Option A (9006) and D (9005): These labels are likely allocated by other routers (e.g., P4 or P5), as they fall outside the sequential range assigned by P3.

Key Points:

Adj-SIDs are local to the router and do not conflict with labels from other nodes.

The sequential allocation depends on the SRLB configuration. If the SRLB starts at 9000, labels 9000 and 9001 may be reserved for other purposes (e.g., node SIDs or reserved blocks), leaving 9002 and 9003 for adjacency labels.

Conclusion: P3 allocates 9002 and 9003 for its two adjacencies. Thus, B and C are correct.

In hot standby (active-active/load balancing) scenarios, Quick Session Backup is critical. This function ensures that session entries are immediately synchronized between firewalls to handle asymmetric traffic (where return traffic goes through a different firewall than the forward traffic).

Without it, the return packet may be dropped due to missing session information on the alternate firewall.

Exact Extract - HCIE-Datacom Security Module:

“When VGMP is in load balancing mode, quick session backup must be enabled to prevent traffic loss due to inconsistent forward and return paths.”

Understanding MPLS Label Retention Modes

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

1️⃣Liberal 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.

2️⃣Conservative 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

IS-IS was originally designed for IPv4, but extensions via TLVs (Type-Length-Value) allow it to support IPv6. These are referred to as New IS-IS TLVs, including TLV 236 (IPv6 Reachability), TLV 232 (IPv6 Interface Address), etc. These TLVs are crucial for IPv6 route computation within IS-IS.

Exact Extract - HCIE-Datacom Guide – IPv6 Routing Protocols Chapter

“IS-IS uses new TLVs such as TLV 236 and TLV 232 to carry IPv6 prefix and interface address information. These TLVs are essential to enable IPv6 route calculation.”

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 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.

InMPLS LDP (Label Distribution Protocol), label retention modes control how labels are stored in theLabel Forwarding Information Base (LFIB).

DU Label Advertisement Mode (Downstream Unsolicited):

Labels areadvertised to all LDP peers without a request.

The receiving routerdecides which label to usefor forwarding.

Liberal vs. Conservative Label Retention:

✅Liberal Label Retention Mode (Correct Answer)

All received labels from all LDP peers are stored.

Even if apeer is not the optimal next hop, its label is retained.

Allowsfaster convergenceduring failures.

❌Conservative Label Retention Mode

Only the label from the best next-hop peer is stored.

Reduces memory usage but can slow down convergence in case of failure.

Reference from Huawei HCIE-Datacom Documentation:

Huawei MPLS LDP Configuration Guide – Liberal vs. Conservative Label Retention

HCIE-Datacom Training Material – Label Advertisement in MPLS Networks

Comprehensive and Detailed In-Depth Explanation:

AfterPortal authenticationon a wireless network, the following parameters can be used for authorization:

free-rule (A):Allows traffic even before authentication.

UCL (B):User Control List, specifying user permissions.

ACL (D):Access Control List, defining permitted or denied traffic.

TheIP address (C), however, isnot used as an authorization parameterdirectly. Instead, IP addresses are typically assigned after successful authentication, and the control policies are applied based on user profiles or access lists.

In BGP, community attributes help control the advertisement scope of BGP routes. Here’s what each option means:

No_Export: This well-known community attribute prevents BGP routes from being advertised to external BGP (EBGP) peers. Routes with this attribute can still be advertised to internal BGP (IBGP) peers within the same AS. This ensures that the route remains within the originating AS.

No_Advertise: This attribute means that the route should not be advertised toanyBGP peer, whether internal or external.

Internet: Indicates that the route can be advertised to all BGP peers, both internal and external, with no restrictions.

No_Export_Subconfed: Similar to No_Export, but it also restricts advertisement to peers within a BGP confederation. It's more specific and not generally used just to keep routes inside one AS.

Therefore, the correct answer isB. No_Export, as it is the attribute that ensures BGP routes remain within the AS by not being sent to EBGP peers.

Ethernet Segment Identifier (ESI) is a 10-byte identifier used in EVPN (Ethernet VPN) to uniquely identify an Ethernet segment across a network, particularly in multi-homing scenarios. It ensures loop prevention and redundancy.

Exact Extract - HCIE-Datacom EVPN Section:

“The ESI is a 10-byte identifier and must be unique across the entire EVPN network. It plays a key role in identifying Ethernet segments in multi-homed environments.”

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.

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.

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.

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.”

MP-BGP is an extension of BGP-4 that supports multi-protocol address families such as IPv6, VPNv4, etc. When PE and CE exchange BGP routes, there is no need to create a BGP process per VPN on the CE. The CE typically runs a standard BGP process, while the PE maintains separate VPN routing tables (VRFs).

Exact Extract - Huawei HCIE-Datacom MP-BGP Chapter:

“CE devices use standard BGP, and multiple VPNs can share the same BGP process on the CE. The PE handles VPN route separation through VRFs and MP-BGP.”

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.

Option A: Correct — both terminal and interface security are important.

Option C: Correct —CAPWAP supports DTLSencryption for secure tunnel communication.

Option D: Correct — intranet security design considersboth wired and wireless.

Option B:Incorrect— traffic suppression (such as broadcast suppression) is implemented usingrate limiting or storm control,not by shutting down interfaces. Shutting down interfaces would disrupt legitimate traffic too.

Correct answer: B

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

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)

EVPN Route Types:

Type 1 (MAC/IP Advertisement Route):Advertises host MAC and IP information —used.

Type 2 (MAC/IP Advertisement Route):Advertises MAC + IP binding for end hosts —used.

Type 3 (Inclusive Multicast Ethernet Tag Route):Used to advertise VXLAN multicast group info —used.

Type 4 (Ethernet Segment Route):Used inmulti-homing scenarios, especially inDC (data center) environments, to coordinate DF election —typically not used in campus VXLAN.

So incampus virtualized networks, which are oftensingle-homed,Type 4 is not required.

Correct answer: C. Type 4

The command port-isolate enable is used on Huawei switches to completely isolate traffic at both Layer 2 and Layer 3 between different interfaces within the same VLAN. This isolation prevents any communication between isolated ports—even if they belong to the same subnet or VLAN—making it a critical security feature in multi-tenant environments.

Usage Context:

Often used in shared service or hotel network scenarios.

Can be applied in access port configurations.

Does not require additional VLAN creation or private VLAN features.

Huawei Datacom Reference:

"To completely isolate Layer 2 and Layer 3 communication between interfaces in the same VLAN, run the port-isolate enable command under the interface view."

(Source: HCIE-Datacom Study Guide V3.0 – Chapter: VLAN & Security Technologies, Section: Port Isolation)

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.”

Before performing anetwork cutover (migration or upgrade), it is essential to collectbaseline datato ensure that services operate normally before and after the change.

Importance of Pre-Cutover Information Collection:

Identifies Network Baseline– Helps comparepre-cutover and post-cutover performance.

Detects Hidden Issues– Ensures that no existing network issues interfere with the cutover process.

Prevents Service Interruptions– Ensures all dependent services are accounted for.

Provides Rollback Plan– If issues arise, administrators canrestore previous configurations.

Reference from Huawei HCIE-Datacom Documentation:

Huawei Network Change Management Guide – Pre-Cutover & Post-Cutover Best Practices

HCIE-Datacom Training Material – Service Assurance & Risk Analysis

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