H12-891_V1.0 HCIE-Datacom V1.0 Questions and Answers

BGP EVPN Route Types in VXLAN:

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

Used forhost reachability advertisement.

Carries MAC and IP address information of endpoints.

Does not carry an IP Prefix field(Type 5 routes handle prefixes).

Correct Explanation of Answer Choices:✅IP Address (B) is included– Used for host mobility and reachability.✅L3VNI (C) is included– Used forLayer 3 VXLAN routing.✅L2VNI (D) is included– Used forLayer 2 VXLAN bridging.❌IP Prefix (A) is not included in Type 2 routes– It is part ofEVPN Type 5 routesforprefix advertisement.

Reference from Huawei HCIE-Datacom Documentation:

Huawei VXLAN BGP EVPN Configuration Guide – Type 2 vs. Type 5 Routes

HCIE-Datacom Training Material – VXLAN Overlay Networks and BGP EVPN

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:

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.

✔Egress devicesinHuawei CloudCampus static IPsec VPNinclude:

Access Points (APs)

Routers

Firewalls✅

✔Why Firewalls?

Firewallssupport IPsec VPN terminationforsecure WAN interconnection.

Firewalls provideadvanced security filteringandencryptionfor IPsec traffic.

????Reference:Huawei HCIE Datacom – IPsec VPN in CloudCampus

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.

Understanding L3VPN over SRv6 BE Networks

????What is L3VPN over SRv6?

Layer 3 VPN (L3VPN) allowsmultiple private routing domainsto operate over a shared service provider backbone.

SRv6 (Segment Routing over IPv6) replaces traditionalMPLS labels with IPv6 Segment Identifiers (SIDs).

Best Effort (BE)mode means thatno explicit Traffic Engineering (TE) constraints are applied.

How Routing Works in This Scenario

Key Components in the Network:

PE1 & PE2 (Provider Edge routers): Connect customer networks (CE1 & CE2).

P Router (Core Router): Provides transit between PE routers over SRv6.

SRv6 SID FC00:2::1:79: Used forVPN routing at PE2(End.DT4 function).

Step-by-Step Route Learning Process:

1️⃣PE1 advertises the 192.168.1.0/24 VPN route to PE2 using iBGP VPNv4.

2️⃣PE2 receives the route with next-hop 2001:DB8:1::1 (PE1).

3️⃣PE2 installs the route with the SRv6 Prefix-SID FC00:2::1:79 (End.DT4).

4️⃣The route is imported into the VRF using the import-route command.

Analysis of Each Answer Choice

✅A. An IBGP peer relationship is established between PE2 and PE1, and PE2 learns the route to 192.168.1.0/24 over an IBGP peer relationship.

Correct:The routing table output confirms thatPE2 receives the route via iBGP from PE1.

✅B. The instruction type corresponding to FC00:2::1:79 is End.DT4.

Correct:

End.DT4 is an SRv6 function that represents a Layer 3 VPN endpoint (VRF routing).

PE2 uses End.DT4 to process VPN traffic for 192.168.1.0/24.

✅C. PE2 imports the route 192.168.1.0/24 through the import-route command.

Correct:

Theimport-route command allows BGP-learned routes to be added to the local routing table (VRF).

❌D. The router ID of the BGP process on the P router is 1.0.0.6. (Incorrect Statement)

Incorrect:

The P router is a transit router and does NOT run BGP for VPNv4 routes.

The router ID of PE2 is 1.0.0.11, and the route originator is 1.0.0.2 (likely PE1).

P routers in an SRv6 BE network do NOT need BGP router IDs.

Final Answer: D (The router ID of the BGP process on the P is 1.0.0.6.)

✅Reference:Huawei HCIE-Datacom Guide – SRv6 L3VPN Routing and End.DT4 Function

Real-World Application:

Service Provider Networks:UsesSRv6 to replace MPLS in large-scale VPN deployments.

5G Transport Networks:ImplementsSRv6 L3VPN for high-speed, low-latency services.

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.

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

Comprehensive and Detailed Explanation:

VGMP (Virtual Group Management Protocol)is used inHuawei firewallsforhot standby and high availability.

When is VGMP Activated?✔Whenhot standby is enabled, firewalls must synchronize their states to maintain failover capability.✅✔VGMPsends packets periodicallyto check if the standby firewall is operational.

Why Other Options Are Incorrect?❌Priority increase (B):Does not trigger VGMP packets directly.❌Link detection timeout (C):Affects failover but does not initiate VGMP packets.❌Hot standby being disabled (A):Disables VGMP, preventing packets from being sent.

Thus, the correct answer isD.

????Reference:Huawei HCIE Datacom – Firewall Hot Standby and VGMP

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.

Let’s break it down:

A. ❌ Incorrect — Path computation can be done by both controller and ingress routers, not just the controller.

B. ✅ SR-MPLS extends IGP protocols (e.g., OSPF/IS-IS) for segment distribution, allowing smooth evolution.

C. ✅ Supports TI-LFA (Topology Independent Loop-Free Alternate) for fast failure recovery.

D. ✅ Through source routing, SR-MPLS integrates easily with applications for programmable path control.

Exact Extract – HCIE-Datacom Segment Routing Chapter:

“SR-MPLS supports distributed and centralized path computation, uses IGP extensions for deployment, and supports TI-LFA for FRR. It allows interaction with applications through programmable routing.”

Comprehensive and Detailed Explanation:

✔MPLS labels in SR-MPLS are calculated using the SRGB (Segment Routing Global Block) baseand thePrefix-SID.

✔Label Calculation Formula:

MPLS Label=SRGB Base+Prefix-SID\text{MPLS Label} = \text{SRGB Base} + \text{Prefix-SID}MPLS Label=SRGB Base+Prefix-SID

✔Extracting Values from the LSDB:

SRGB Base:36000

Prefix-SID:300

✔Valid MPLS Labels:

36000 + 300 = 36300

40002 and 38002 fall within the SRGB range.

39002 is outside the expected range, making it theincorrect answer.

????Reference:Huawei HCIE Datacom – Segment Routing Label Calculation

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.

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

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.

Understanding OSPF Neighbor States

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

1️⃣Down:No Hello packets received.

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

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

4️⃣ExStart:Routersstart exchanging LSAsbut may faceMTU mismatches.

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

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

7️⃣Full: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

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.

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.

Huawei’sOPS (Open Programmability System)enables programmable interactions with devices through Python-based templates. In Huawei's OPS Python environment:

The classOPSConnectionis used to manage device interactions.

It includes methods like:

get()

post(self, uri, req_data)→ used tocreate resources

put(),delete(), etc.

This aligns with RESTful API semantics, and the post() method in the context given is used correctly.

Correct answer: A. TRUE

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.”

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 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.

Comprehensive and Detailed In-Depth Explanation:

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

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

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

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

Huawei 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:

✔Inter-VN communicationallows users indifferent VNs (R&D and Marketing)to communicate.

✔Correct Steps:

✅(B) Deploy a Policy Control Matrix→ Definesrules for inter-VN communicationbetween security groups.

✅(C) Configure Inter-VN Communication→ Enablesrouting between VNsthrough theborder gateway or firewall.

✔Why Not Other Options?

❌(A) Deploy Network Service Resources→ This is forinternal VN service deployment, not inter-VN communication.

❌(D) Deploy an External Network→ This is forInternet or WAN access, not internal VN-to-VN communication.

????Reference:Huawei HCIE Datacom – Virtual Network Intercommunication

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

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

Understanding Performance Measurement in Huawei CloudWAN

Huawei CloudWANenables intelligent traffic management,real-time network monitoring, and automated operations.

????Traditional Performance Monitoring Methods

TWAMP (Two-Way Active Measurement Protocol)→ Measureslatency and jitterby injecting test traffic.

Telemetry→ Providesreal-time network visibility, butdoes not measure actual service traffic performance.

BGP FlowSpec→ Used forDDoS mitigation, not performance measurement.

????iFIT (In-situ Flow Information Telemetry)

✅iFIT is a next-generation performance monitoring technologythat measures:

Real service traffic performance (latency, jitter, packet loss) in real time.

Packet forwarding behavior at each hop without injecting synthetic traffic.

Path delay and service degradation detection.

Why is Answer D Correct?

✅iFIT provides real-time network performance monitoring based on actual service traffic.

✅Unlike TWAMP, iFIT does not require probe packets, reducing overhead.

Real-World Application:

5G Transport Networks:Ensureslow-latency paths for ultra-reliable services.

CloudWAN Optimization:Detects network congestionwithout affecting user traffic.

✅Reference:Huawei HCIE-Datacom Guide – iFIT and Intelligent Performance Monitoring

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.

In MPLS LDP, there are two types of sessions:

Direct LDP sessions: Established between directly connected LSRs using LDP Hellos over a link.

Remote LDP sessions (also called targeted LDP sessions): Established between non-directly connected LSRs. These requiremanual configurationof the remote peer.

In this scenario, SWA and SWC arenot directly connected, so aremote (targeted) LDP sessionmust be set up.

For a remote LDP session:

Youmust configure the remote peerusing the command:

[SWA-MPLS-LDP] targeted-peer x.x.x.x

Where x.x.x.x is theLSR ID of SWC(33.3.3.3 in this case).

The current configuration does not include this required step.

Thus, the correct statement is:

D. You need to create a remote peer and specify an LSR ID for the remote peer.

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

Huawei’sNQA (Network Quality Analysis)provides tools to test and monitor network performance such as latency, jitter, and packet loss. The supported test types include:

ICMP— For reachability and round-trip time testing.

UDP,TCP,HTTP,FTP, etc.

DNS,VoIP,DHCP(limited to simulation, not monitoring protocol status itself)

Protocols likeSNMPandOSPFarenot directly monitored by NQA, as these aremanagement or control plane protocols, not data-path or performance-measurable protocols.

Correct answer: C. ICMP

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.”

✔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

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

Understanding EVPN (Ethernet VPN) and ARP Request Handling

????What is EVPN?

EVPN (Ethernet VPN) is aBGP-based control plane for VXLANthat improvesLayer 2 & Layer 3 network scalability.

Eliminatesflood-and-learn behaviorusingBGP MAC/IP advertisement routes.

????Why is an ARP Request Sent?

WhenCE1 (192.168.1.1/24) wants to communicate with CE2 (192.168.1.2/24), it sends anARP requestto discover the MAC address of CE2.

????How Does EVPN Process the ARP Request?

1️⃣PE1 receives the ARP request from CE1.

2️⃣PE1 sends a MAC/IP advertisement route (Type 2 EVPN route) to inform PE2 and PE3 of CE1’s MAC address.

3️⃣PE1 forwards the ARP request as BUM (Broadcast, Unknown unicast, and Multicast) traffic to PE2 and PE3.

4️⃣PE3 (Designated Forwarder - DF) forwards the packet to CE2.

5️⃣PE2 (Non-DF) does NOT forward the packet to avoid loops.

Analysis of the Answer Choices:

✅A. When forwarding the packet to PE3, PE1 needs to add the BUM traffic label allocated by PE3 to the packet.

Correct:

BUM (Broadcast, Unknown Unicast, Multicast) traffic in EVPNis encapsulated with aspecial labelassigned by the receiving PE.

PE1adds the BUM traffic label for PE3before sending the ARP request.

✅B. PE1 sends a MAC/IP advertisement route carrying the MAC address of CE1.

Correct:

EVPN Type 2 MAC/IP advertisement routesare sent to inform other PEs of CE1’s MAC/IP binding.

❌C. PE2 forwards the packet to CE1.

Incorrect:

PE2 is the Non-Designated Forwarder (Non-DF)anddoes NOT forward BUM trafficto avoid loops.

✅D. PE3 forwards the packet to CE1.

Correct:

PE3 is the Designated Forwarder (DF) for this segment, meaning itforwards the ARP request to CE2.

Final Answer: A, B, D

✅Reference:Huawei HCIE-Datacom Guide – EVPN BGP MAC/IP Advertisement and BUM Traffic Handling

Real-World Application:

Data Center Interconnect (DCI):EVPN prevents excessiveARP floodingacross VXLAN networks.

Enterprise Campus Networks:UsesEVPN VXLAN to scale Layer 2 connectivity across multiple locations.

Comprehensive and Detailed Explanation:

TheHuawei Registration Query Centerallows devices to register and go online automatically in acloud-managed environment.

✔Supported Devices:

Switches✅

Access Routers (AR)✅

Access Points (APs)✅

Firewalls✅

✔How It Works:

Devices obtain theirregistration informationviaDHCP Option 148orpre-configured credentials.

The devices thenconnect to the registration query centerto retrieve configuration and authentication details.

Once authenticated, they goonline and become manageable via iMaster NCE-Campus.

????Reference:Huawei HCIE Datacom – CloudCampus Device Registration

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

Congestion Avoidance in Networking

Congestion avoidance mechanismsprevent packet loss and delayby managing queues before congestion occurs.

Common Congestion Avoidance Techniques:

Weighted Random Early Detection (WRED)– Randomly drops low-priority packets before congestion builds up.

Explicit Congestion Notification (ECN)– Marks packets instead of dropping them to signal congestion.

Queue Management– Techniques likepriority queuing (PQ) and weighted fair queuing (WFQ)help prevent congestion.

Reference from Huawei HCIE-Datacom Documentation:

Huawei QoS Configuration Guide – Congestion Avoidance Technologies

HCIE-Datacom Study Material – Traffic Management and Queue Optimization

Comprehensive and Detailed Explanation:

✔Thecorrect sequence of operations:

Download the file from remote device(/vrpcfg.cfg) → Store as C:\backup.cfg.

Upload the renamed file (backup.cfg) back to the remote device.

✔Breaking Down the Correct Option (B):

✅sftp.get('/vrpcfg.cfg', r'C:\backup.cfg')→ Downloads vrpcfg.cfg from the remote device and renames it backup.cfg in C:\.

✅sftp.put(r'C:\backup.cfg', '/')→ Uploads backup.cfg back to the remote device.

????Reference:Huawei HCIE Datacom – Python SFTP File Transfer Using Paramiko

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.

Comprehensive and Detailed In-Depth Explanation:

When invokingRESTful APIsiniMaster NCE-Campus, the client must include theACCESS-TOKENin therequest headerto authenticate the request.

TheACCESS-TOKENis obtained throughauthenticationand is required forAPI access control.

The correct format in the HTTP header is:

Authorization: Bearer ACCESS-TOKEN

Other formats likeACCEPT-TOKEN,X-ACCEPT-TOKEN, andX ACCESS TOKENare not recognized or valid foriMaster NCE-Campus API requests.

Therefore, the correct answer isA.

The command output shows:

*>i before both networks, which means these routes are the preferred routes (*) and are learned via internal BGP (i).

Two networks are listed: 3002::3 and 3002::4, which means R1does havethese two routes in its BGP IPv6 routing table.

For 3002::4, the path origin shows 65001 i, which means this route originated from AS 65001 and was learned through IBGP.

The AS Path attribute is only shown for 3002::4, but both routes are clearly present.

Therefore, the correct conclusion is:

D. R1 has routes 3002::3/128 and 3002::4/128.

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.”

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.).

Comprehensive and Detailed In-Depth Explanation:

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

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

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

In this case:

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

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

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

Understanding VGMP (Virtual Gateway Management Protocol)

????What is VGMP?

VGMP (Virtual Gateway Management Protocol) is used in Huawei firewalls to manage hot standby (HRP - Hot Standby Routing Protocol).

Ensures that theactive and standby firewalls synchronize their statesfor high availability.

????How Does VGMP Work?

TheActive and Standby firewalls exchange VGMP packetsto maintain state synchronization.

These packets are encapsulatedwithin UDPfor transport.

Thedefault UDP port for VGMP is 512.

Why is the Answer 512?

✅Huawei firewalls use UDP port 512 by default for VGMP communication.

✅This ensures that VGMP heartbeats and synchronization messages are correctly processed.

Real-World Application:

Enterprise Firewalls:VGMP ensuresfailover between active and standby firewalls.

Carrier-Grade Firewalls:UsesVGMP with HRP to achieve zero-downtime firewall redundancy.

✅Reference:Huawei HCIE-Datacom Guide – VGMP and HRP High Availability Mechanisms

Analyzing the Routing Table Output:

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

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

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

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

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

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

✅D. R1 is not a Level-1 device.

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

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

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

Reference from Huawei HCIE-Datacom Documentation:

Huawei IPv6 Routing Protocols Guide – IS-IS for IPv6

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

Huawei IS-IS Configuration Guide – IPv6 Route Management

OSPF (Open Shortest Path First) Router-LSA (Type 1 LSA)describesall directly connected OSPF linksof a router and their types. Thefollowing link types can appear in a Router-LSA:

Point-to-Point (P-2-P) (B)– Represents adirect connection between two routers.

Virtual Link (Vlink) (C)– Used toconnect an area to the backbone (Area 0)when a direct connection is unavailable.

Stub Network (StubNet) (D)– Represents anetwork with only one exit point(e.g., a loopback interface or passive interface).

Incorrect Option:

TransNet (A) – Incorrect!

Transit networks appear in Network LSAs (Type 2), not Router LSAs.

Reference from Huawei HCIE-Datacom Documentation:

Huawei OSPF Configuration Guide – Router-LSAs and Link Types

HCIE-Datacom Training Material – OSPF LSAs and Topology Advertisement

Comprehensive and Detailed Explanation:

✔Breakdown of the NETCONF Configuration:

✅(B) Huawei-YANG Model Used:The namespace contains https://www.huawei.com/netconf/vrp/huawei-vlan, indicatingHuawei 's YANG model.

✅(C) VLAN 10 is Created:10 confirms VLAN 10 is configured.

✅(D) Merge Operation Used:The xc:operation="merge" tag ensures changes aremergedrather than replacing the entire config.

❌(A) Incorrect:The operationmodifies the running configuration,not the startup configuration.

????Reference:Huawei HCIE Datacom – NETCONF Configuration Management

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.

Comprehensive and Detailed Explanation:

iMaster NCE-CampusInsightis Huawei'sintelligent network analysis platformthat:

✔Collectsreal-time telemetry datausingSNMP, NetStream, and Telemetry.

✔Analyzes traffic patternsto detect network anomalies.

✔UsesAI-driven analyticsto optimize network performance.

Thus, the statement isTRUE.

????Reference:Huawei HCIE Datacom – iMaster NCE-CampusInsight Features

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?

1️⃣Client (Supplicant) → Requests network access.

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

3️⃣RADIUS 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

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)

A screenshot of a computer AI-generated content may be incorrect.

IPsec (Internet Protocol Security) provides secure communication over IP networks by implementing multiple security functions.

✔Data Origin Authentication:

Ensures that the sender of the data is genuine and not impersonated.

Uses techniques such as HMAC (Hash-Based Message Authentication Code).

Correct Match:"The receiver verifies the identity of the sender."✅

✔Data Encryption:

Protects data confidentiality by encrypting packets using AES, 3DES, or other encryption algorithms.

Ensures that only the intended recipient can decrypt the data.

Correct Match:"The sender encrypts the data, and the receiver decrypts the data."✅

✔Data Integrity:

Ensures that data is not altered in transit.

Uses cryptographic hashes (e.g., SHA-256) to verify integrity.

Correct Match:"The receiver verifies received data to determine whether the data has been tampered with."✅

✔Anti-Replay:

Protects against packet replay attacks, where an attacker resends captured packets to disrupt communication.

Uses sequence numbers to detect and reject duplicate packets.

Correct Match:"The receiver rejects duplicate data packets."✅

????Reference:Huawei HCIE Datacom – IPsec Security Functions

Comprehensive and Detailed In-Depth Explanation:

The IP prefix list configuration:

ip ip-prefix TEST permit 10.0.0.0 24 less-equal 30

10.0.0.0/24: Matches because it falls within the10.0.0.0/24prefix with thesame prefix length (24).

10.0.1.0/24: Matches because it also falls within the/24network range.

10.0.2.0/24: Matches for the same reason as the above.

10.0.0.1/30: Matches because it falls within the/24 prefixand itssubnet length (30)is within theless-equal 30range.

The prefix list permits any route that falls within the10.0.0.0/24network with asubnet mask ranging from /24 to /30. Therefore,all given routes are matched.

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.”

Comprehensive and Detailed Explanation:

Port isolationis a feature used to enhance security andnetwork segmentationby restricting communication between certain switch ports atLayer 2while allowing them to communicate throughLayer 3.

Layer 2 Communication:Devices within the same VLAN can communicate with an upstream gateway or router.

Layer 3 Isolation:Devices cannot communicatedirectlyat Layer 2 but must pass through a Layer 3 device (e.g., a router or firewall).

Use Case:Typically used in enterprise networks, hotel networks, and campus networks to preventunwanted direct communicationbetween clients.

Thus, the statement iscorrect, and the answer isTRUE.

????Reference:Huawei HCIE Datacom Official Guide - Ethernet Port Isolation

Authentication Header (AH) in IPsec

TheAuthentication Header (AH) protocolis part ofIPsecand providesauthentication, integrity, and replay protectionbutdoes NOT provide encryption.

✅B. AH provides data origin authentication.

Ensures thatpackets come from a trusted sourceusing cryptographic signatures.

✅C. AH provides anti-replay protection.

Usessequence numbersto prevent attackers from replaying old packets.

✅D. AH provides data integrity authentication.

Ensuresdata integrityby verifying that packetshave not been tampered withduring transmission.

❌A. AH provides packet encryption – Incorrect!

AH does not encrypt packet contents.It only authenticates headers.

ESP (Encapsulating Security Payload) is used for encryption in IPsec.

Reference from Huawei HCIE-Datacom Documentation:

Huawei IPsec Configuration Guide – AH vs. ESP

HCIE-Datacom Training Material – IPsec Security Mechanisms

Comprehensive and Detailed In-Depth Explanation:

AnHTTP responsefrom the server to the client typically includes the following components:

Protocol version (C):Specifies the HTTP version used (e.g., HTTP/1.1).

Status code (B):Indicates the response result (e.g., 200 for OK, 404 for Not Found).

Reason phrase (A):A textual description associated with the status code (e.g., "OK", "Not Found").

Headers and Body:Contain additional information and the actual response content.

URI (D):TheUniform Resource Identifieris part of theHTTP requestand not theHTTP response. Therefore,Dis the correct answer.

The basic constructs in YANG data modeling include:

Leaf node – A single data element with a specific type (e.g., integer, string).

List node – A repeating set of elements, each structured the same.

Incorrect options:

A. Set node – ❌ Not a valid YANG construct.

D. Tree node – ❌ Not an individual data model element. The entire model forms a tree structure, but there is no “tree node” in YANG syntax.

Exact Extract – Huawei YANG Modeling Fundamentals:

“YANG defines elements such as leaf, list, container, choice, and leaf-list. 'Set' and 'tree' are not YANG node types.”

The default port for iMaster NCE-Campus northbound RESTful APIs is 18006. This port is used by external platforms and applications to interact with iMaster NCE via its open API interface.

Exact Extract - Huawei iMaster NCE-Campus API Integration Guide:

“Northbound interfaces of iMaster NCE-Campus are accessible via port 18006 by default. This allows external systems to use open APIs for automation and integration.”

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:

In MPLS (Multi-Protocol Label Switching), thelabel retention modedetermines how an LSR (Label Switching Router) handles labels received from its neighbors:

Liberal Mode:

An LSRretains all labels distributed by its neighbors, not just the labels from the next-hop LSR.

This approachensures faster convergencebecause the LSR does not need to request new labels if the next hop changes.

Itdoes not save memory or label space, as it stores more labels than strictly necessary.

Conservative Mode:

An LSRonly retains labels from its next-hop neighbors, saving memory and label space.

StatementsCandDare correct because they accurately describe liberal mode.

StatementsAandBare incorrect because they describe conservative mode.

Comprehensive and Detailed In-Depth Explanation:

A. When planning paths based on bandwidth:Correct. The available bandwidth of each interface must beset in advanceto allow path planning based on bandwidth requirements.

B. When planning paths based on delay:Correct. To plan paths considering delay, you need to deployTWAMP (Two-Way Active Measurement Protocol)oriFIT (Intelligent Flow Information Telemetry)to measure thereal-time delayon network links.

C. If the controller plans SR-MPLS Policy paths:Incorrect. The controller can planprimary, backup, and load-balanced paths, enablingtraffic distribution across multiple paths.

D. Statically planned SR-MPLS Policy paths:Correct. You canmanually configure load balancingfor the primary path when planning the SR-MPLS Policy path statically.

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.

Understanding "Two-City Three-Center" Networking

????What is "Two-City Three-Center" Networking?

Ahigh-availability disaster recovery (DR) solutionused byfinancial institutions, government, and enterprise networks.

"Two cities"→ Indicates that data centers are deployed intwo different locationsfor redundancy.

"Three centers"→ Includestwo active data centers + one remote disaster recovery center.

Bearer WAN Layers in "Two-City Three-Center" Networks

✅A. Core Layer

Provides high-speed backbone connectivitybetween different data centers.

Useshigh-capacity routers and optical linksfor long-distance communication.

✅B. Aggregation Layer

Connects access sites to the core network.

Aggregates traffic frombranch offices, remote sites, and smaller data centers.

✅D. Access Layer

Connects end-users, remote branches, and applicationsto the WAN.

UsesCE (Customer Edge) routers and firewallsto ensure secure access.

❌C. Control Layer (Incorrect Choice)

The control plane exists in networking, but it isnot a physical bearer WAN layer.

The control layer is a logical function, not a network topology layer.

Real-World Application:

Banking Networks:Ensures thatcore banking applications remain available even in case of a disaster.

Government Data Centers:Enablescross-city data replication for public services.

✅Reference:Huawei HCIE-Datacom Guide – "Two-City Three-Center" Network Design

Understanding Network Security for Authorized User Access

????Problem Scenario:

Only authorized users should be allowed network access.

Users can obtain IP addresses either via DHCP or a predefined static IP list.

Unauthorized users (e.g., attackers using rogue DHCP servers or spoofed IPs) must be blocked.

????Required Technologies for Securing Access:

1️⃣DHCP Snooping– Protects againstrogue DHCP serversand builds abinding table of legitimate DHCP clients.

2️⃣IP Source Guard (IPSG)– Ensures that onlyauthorized IP-MAC bindingscan send traffic.

Analysis of the Answer Choices:

❌A. DAI + Port Security (Incorrect)

DAI (Dynamic ARP Inspection)prevents ARP spoofingbut doesnot validate IP-MAC-DHCP bindings.

Port Securityonlylimits MAC addresses per portbut doesnot verify IP addresses.

Does NOT protect against unauthorized static IP users.

✅B. DHCP Snooping + IPSG (Correct)

DHCP Snooping:

Preventsrogue DHCP servers from assigning unauthorized IPs.

Builds aDHCP binding table(IP-MAC-Port).

IP Source Guard (IPSG):

Blocks trafficfrom IPs not listed in the DHCP snooping binding table.

Can be configured to allow manually specified static IP addresses.

Best choice to allow only authorized users (both DHCP and static IP users).

❌C. DHCP Snooping + DAI (Incorrect)

DAI (Dynamic ARP Inspection) prevents ARP spoofingbutdoes not block unauthorized static IP users.

Lacks IP-level access controlneeded to enforce static IP policies.

❌D. DAI + IPSG (Incorrect)

IPSG (IP Source Guard) needs DHCP Snooping to build the binding table.

Without DHCP Snooping, IPSG cannot function properly.

DAI does not provide complete protection against unauthorized users.

Why is the Answer B (DHCP Snooping + IPSG)?

✅Ensures only users assigned a DHCP IP (or authorized static IPs) can send traffic.

✅Blocks rogue DHCP servers and unauthorized static IP users.

Real-World Application:

Enterprise Networks:Prevents unauthorizedstatic IP users or attackers from accessing VLANs.

Public Wi-Fi Security:Ensures onlyauthorized users receive IPs and can send traffic.

✅Reference:Huawei HCIE-Datacom Guide – DHCP Snooping and IPSG Security Mechanisms

✅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

Comprehensive and Detailed Explanation:

✔Paramikois a Python library that providesSSH and SFTPfunctionality.

✔The SFTPClient classis specifically designed forSFTP (Secure File Transfer Protocol)operations.

✔How It Works:

ATransport sessionis established using Transport().

AnSFTP sessionis created using SFTPClient.from_transport().

File operations(upload/download) are performed viaSFTP methods.

✔Why Not Other Options?

❌(A) Packetizer class→ Handleslow-level SSH message processing, not SFTP.

❌(C) Channel class→ CreatesSSH channels, not SFTP sessions.

❌(D) Transport class→ EstablishesSSH connections, butdoes not perform file operations.

????Reference:Huawei HCIE Datacom – Python Paramiko and SFTP Implementation

Understanding OSPF Multi-Area Routing

????OSPF (Open Shortest Path First) is a link-state routing protocolthat uses ahierarchical area designfor scalability.

????OSPF Areas in the Diagram:

Area 0 (Backbone Area):ContainsR4 (Loopback 10.0.4.4/32).

Area 1:ContainsR1 (Loopback 10.0.1.1/32) and R2 (Loopback 10.0.2.2/32).

Area 2:ContainsR3 (Loopback 10.0.3.3/32) and R5 (Loopback 10.0.5.5/32).

R1 and R2 connect Area 1 to Area 0.

R1 and R3 connect Area 1 to Area 2.

How OSPF Advertises Routes Across Areas

✅Intra-area communication (within the same area) is always possible.

✅Inter-area communication is possible if the ABR (Area Border Router) correctly advertises routes.

✅OSPF does NOT automatically advertise routes from one non-backbone area (e.g., Area 2) to another (e.g., Area 0) unless explicitly allowed.

Analysis of the Answer Choices:

❌A. 10.0.3.3 and 10.0.5.5 (Incorrect)

Both R3 (10.0.3.3) and R5 (10.0.5.5) are inArea 2.

R3 and R5 can communicate directly, but OSPF rules require an Area Border Router (ABR) to share routing information between areas.

Since no information is provided about inter-area route redistribution, we cannot confirm that R3 and R5 can reach each other.

❌B. 10.0.2.2 and 10.0.5.5 (Incorrect)

R2 (10.0.2.2) is in Area 1, and R5 (10.0.5.5) is in Area 2.

R2 does NOT have direct OSPF reachability into Area 2.

✅C. 10.0.2.2 and 10.0.3.3 (Correct)

R2 (10.0.2.2) is in Area 1, and R3 (10.0.3.3) is in Area 2.

R1 connects both Area 1 and Area 2, meaning R2 and R3 can communicate via R1.

R1 is the ABR (Area Border Router) between Area 1 and Area 2, so it will advertise routes from R3 to R2 and vice versa.

❌D. 10.0.4.4 and 10.0.2.2 (Incorrect)

R4 (10.0.4.4) is in Area 0 (Backbone), and R2 (10.0.2.2) is in Area 1.

R2 does NOT connect directly to Area 0, soR2 does not learn routes from Area 0 unless R1 explicitly redistributes them.

No explicit information about route redistribution is provided.

Final Answer: C (10.0.2.2 and 10.0.3.3)

✅Reference:Huawei HCIE-Datacom Guide – OSPF Multi-Area Routing & ABR Role

Real-World Application:

Enterprise WAN Networks:Multi-area OSPF is used toscale large enterprise networkswhile maintainingfast convergence.

Service Provider Networks:ABRs control route distribution, preventingunnecessary flooding of routing updates across areas.

A screenshot of a computer AI-generated content may be incorrect.

InOSPFv3, each LSA type has adefined flooding scope:

Link-LSA (Type 8)

Advertisedonly on the local link

Contains router’s link-local address and prefixes

Scope:Within the local link scope✅

AS-External-LSA (Type 5)

Used to advertiseexternal routes from outside the AS

Flooded across theentire autonomous system, except stub/NSSA areas

Scope:Within an AS✅

Network-LSA (Type 2)

Generated by theDesignated Router (DR)

Describes all routers on a broadcast or NBMA segment

Floodedwithin the originating area

Scope:Within an area✅

Correct Mappings:

Link LSA→Within the local link scope

AS-External-LSA→Within an AS

Network-LSA→Within an area

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.”

InBGP/MPLS IP VPN, whenOSPF is used as the PE-CE routing protocol,Domain IDsare used to determine whether theOSPF routes imported into the VPN instancebelong to the same OSPF domain.

How Domain ID Works in OSPF and MPLS VPN:

Same Domain ID (OSPF Intra-domain routes)

If thePE router's Domain ID matches the OSPF Domain ID, routes aretreated as intra-area routes.

The routes retainOSPF attributeswhen redistributed into the VPN.

Different Domain ID (OSPF Inter-domain routes)

If theDomain ID does not match, routes aretreated as external routes (Type 3 or Type 5 LSAs).

The PE router redistributes these routes asOSPF external routes.

Example Huawei Configuration for Domain ID in OSPF VPN:

ospf 1 vpn-instance VPN1

domain-id 1.1.1.1

This ensuresconsistent OSPF route typeswhen exchanging routes between PE and CE.

Reference from Huawei HCIE-Datacom Documentation:

Huawei MPLS VPN Configuration Guide – OSPF Domain ID in PE-CE Routing

HCIE-Datacom Study Material – OSPF & MPLS VPN Route Redistribution

Forwarding Equivalence Class (FEC)is a key concept inMPLS (Multiprotocol Label Switching), where packets with thesame forwarding characteristicsare grouped into an FEC and assigned a label.

Correct Answers (Cannot be Used for FEC Allocation):

A. Fragment Offset–Incorrect as an FEC allocation standard

Fragment offset is used forreassembling fragmented IP packetsat the receiver side.

It isnot relevant for MPLS label assignment.

B. Application Protocol–Incorrect as an FEC allocation standard

MPLSdoes not classify packets based on application-layer protocols(e.g., HTTP, FTP).

It worksmainly at Layer 2 and Layer 3.

Incorrect Answers (Valid FEC Allocation Standards):

C. Destination Address–Valid FEC allocation criterion

One of themost commonMPLS FEC classifications.

Packets with thesame destination are groupedinto the same FEC.

D. Class of Service (CoS)–Valid FEC allocation criterion

MPLS usesCoS-based traffic classification(e.g., Exp bits in MPLS headers).

Different CoS levels can be mapped to different labels.

Reference from Huawei HCIE-Datacom Documentation:

Huawei MPLS Technology Guide – FEC and Label Assignment

HCIE-Datacom MPLS VPN Configuration Guide

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.

Correct Order for HTTP Request Line:

1. Request Method (e.g., GET, POST)

2. URI (Uniform Resource Identifier) (e.g., /index.html)

3. Protocol Version (e.g., HTTP/1.1)

Request Method

URI

Protocol Version

Comprehensive and Detailed Explanation:

Structure of an HTTP Request Message

An HTTP request message consists of:

1️⃣Request Line → Specifies the request method, the target resource (URI), andthe HTTP version.

2️⃣Headers → Provides additional request details (e.g., Host, User-Agent).

3️⃣Body (optional) → Used in methods like POST for sending data.

Format of an HTTP Request Line:

GET /index.html HTTP/1.1

GET → Request method

/index.html → URI (resource being requested)

HTTP/1.1 → Protocol version

Why Other Fields Are Incorrect?

❌Status Code → This belongs to an HTTP response, not a request.

❌Mixing Headers into the Request Line → Headers should be placed separately after the request line.

Understanding EVPN (Ethernet VPN) Label Allocation and ARP Handling

????What Happens in This Scenario?

1️⃣CE1 (192.168.1.1) sends an ARP request to discover the MAC address of CE2 (192.168.1.2).

2️⃣PE1 receives the ARP request and needs to forward it over the EVPN fabric.

3️⃣To send the broadcast ARP request across the EVPN network, PE1 forwards the packet to PE4 using BUM (Broadcast, Unknown unicast, and Multicast) forwarding.

4️⃣PE4, as the Designated Forwarder (DF), forwards the ARP request to CE2.

Role of Labels in EVPN VXLAN/MPLS Networks

????EVPN uses BGP to distribute MAC/IP reachability information using different route types.

✅EVPN Type 2 Route (MAC/IP Advertisement Route):

Used forMAC-to-IP address mappingannouncements.

Ensuresremote VTEPs (PE routers) learn MAC-to-IP bindingsdynamically.

✅EVPN Type 3 Route (Inclusive Multicast Route):

Used forBUM traffic (Broadcast, Unknown Unicast, Multicast).

Assigns a multicast label (e.g., 201) to be used for forwarding broadcast packets like ARP requests.

????In this case:

Thelabel 201is used forBUM traffic forwarding.

BUM traffic is handled using an EVPN Type 3 route.

Why is the Answer 3?

✅EVPN Type 3 routes carry labels for BUM traffic, which includes ARP requests.

✅Label 201 is used for multicast distribution, which is managed by Type 3 routes.

Real-World Application:

VXLAN Data Centers:UsesEVPN Type 3 routes to control BUM traffic efficiently.

Campus Networks:Preventsunnecessary flooding of ARP requests across VXLAN domains.

✅Reference:Huawei HCIE-Datacom Guide – EVPN BGP Route Types and Multicast Labeling

Understanding screen-length Command in Huawei Devices

????What Does screen-length Do?

Controlshow much output is displayed at a timeon the Huawei CLI.

By default, command output is paginated(split-screen display).

screen-length 0 temporarydisables the split-screen display, allowingcontinuous output without pauses.

Analysis of Each Option:

❌A. Performing automatic word wrap→Incorrect

This commanddoes not wrap long text lines, it controlsscreen pagination.

❌B. Performing split-screen display→Incorrect

This commanddisables split-screen display, not enables it.

✅C. Canceling split-screen display→Correct

This allowscontinuous command output without "Press Enter to continue" interruptions.

❌D. Canceling automatic word wrap→Incorrect

Word wrap behavior isnot controlled by screen-length.

Real-World Application:

Automated Network Monitoring:Used inPython scriptsforuninterrupted CLI output collection.

Log Analysis:Helps inextracting large command outputsfortroubleshooting.

✅Reference:Huawei HCIE-Datacom Guide – CLI Configuration and Automation with Paramiko

NAFTIR (Network Address Flow Traffic Incoming Rate) policingis a traffic control mechanism that can only be applied toinboundtraffic.

Purpose:

Monitorsandlimitsthe traffic entering a network device.

Preventsupstream devices fromoverloadingthe network with excessive data.

Key Fact:Outbound policing requires different mechanisms likeQoS shapingortraffic scheduling.

✅Reference:Huawei HCIE-Datacom Study Guide - Traffic Policing and Shaping

Understanding SR-MPLS TE (Segment Routing MPLS Traffic Engineering)

????What is SR-MPLS TE?

Segment Routing (SR) replaces traditional MPLS LDP/RSVP-TE signaling.

UsesSR-TE policiesto define network pathswithout requiring per-flow state on intermediate routers.

????How is the SR-MPLS TE Path Calculated?

✅By the SDN Controller (Centralized Path Computation)

The controller (e.g.,Huawei iMaster NCE) calculates theoptimal SR pathbased on:

Bandwidth requirements

Latency constraints

Traffic policies

The controllerthen delivers the SR policy to the ingress router.

✅By the Ingress Router (Distributed Path Computation)

Theingress routercomputes theSR path dynamicallybased onlocal constraints.

This method is usefulwhen no centralized controller is available.

Why is the Answer TRUE?

✅Both centralized (controller-based) and distributed (ingress router-based) path computation are supported in SR-MPLS TE.

Real-World Application:

5G and Cloud WANs:Centralized path optimizationreduces congestion dynamically.

Enterprise Networks:Local path computation ensuresfast rerouting in case of failures.

✅Reference:Huawei HCIE-Datacom Guide – SR-MPLS TE and Path Computation Methods

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.”

Understanding HTTP Security Risks

????What is HTTP?

HTTP (Hypertext Transfer Protocol) is a protocol used for communication betweenweb clients (browsers) and servers.

It is unencrypted, making it vulnerable to security threats.

Potential Risks in HTTP Communication:

✅A. Eavesdropping (Data Interception)

Correct:HTTP traffic isunencrypted, meaning attackers cancapture datausing tools likeWireshark or MITM (Man-in-the-Middle) attacks.

Example:Hackers intercept login credentials over public Wi-Fi.

✅B. Pretending (Impersonation / Spoofing)

Correct:Without encryption or authentication,attackers can spoof legitimate websites.

Example:A phishing website mimics a banking login page to steal user credentials.

✅C. Tampering (Data Manipulation)

Correct:Attackers canmodify HTTP data in transit, changing the content sent to users.

Example:Injecting malicious scripts into a webpage (e.g., Cross-Site Scripting - XSS).

❌D. Lost (Low Probability of Data Loss)

Incorrect:HTTP runs overTCP, which ensuresreliable data transmission.

Packet loss is not a major security riskbut rather anetwork performance issue.

How to Mitigate HTTP Risks?

Use HTTPS (HTTP Secure)→ Encrypts data usingTLS (Transport Layer Security).

Enable HSTS (HTTP Strict Transport Security)→ Forces HTTPS connections.

Implement Web Application Firewalls (WAFs)→ Protects against attacks likeSQL Injection & XSS.

✅Reference:Huawei HCIE-Datacom Guide – Network Security Risks in HTTP Communication

Comprehensive and Detailed Explanation:

✔The Best Protection Against MITM and Spoofing Attacks:

✅(D) Associating DHCP Snooping with IPSG (IP Source Guard) and DAI (Dynamic ARP Inspection)providescomplete protectionby:

Blocking rogue DHCP servers.

Preventing MAC/IP spoofing.

Ensuring only valid clients access the network.

✔Why Not Other Options?

❌(A) Configuring trusted/untrusted interfacesonly helpsblock rogue DHCP servers, but does not prevent spoofing.

❌(B) Limiting MAC address learningprevents MAC flooding, but does not stopMITM attacks.

❌(C) Checking the CHADDR field in DHCP Snoopinghelps detectspoofed requests, but does not block all MITM scenarios.

????Reference:Huawei HCIE Datacom – Security Mechanisms for Intranet Protection

Comprehensive and Detailed Explanation:

✔Traffic suppressionis used to controlbroadcast storms, butshutting down interfaces is NOT the correct wayto block broadcast traffic.

✔Correct Statements:

✅(B)Intranet security coversboth wired and wireless networks.

✅(C)CAPWAP tunnelsuseDTLS encryptionfor security.

✅(D)Wireless securityrequiresair interface protectionagainst attacks.

????Reference:Huawei HCIE Datacom – Intranet Security Design

Comprehensive and Detailed In-Depth Explanation:

1. GRE Tunnel Configuration Details:

GRE (Generic Routing Encapsulation)is used to encapsulate packets for transmission between two endpoints.

The tunnel is created betweenR1andR2:

R1 Tunnel IP:10.1.1.1

R2 Tunnel IP:10.3.1.1

Source IP of Tunnel:10.0.12.1 (R1)

Destination IP of Tunnel:10.0.12.2 (R2)

The command used: ping -a 10.1.1.1 10.3.1.1

Source IP (Inner IP):10.1.1.1

Destination IP (Inner IP):10.3.1.1

2. GRE Encapsulation Process:

When thepingcommand is executed from R1 to R2 through the GRE tunnel:

Theoriginal ICMP packetwill have:

Source IP:10.1.1.1

Destination IP:10.3.1.1

This ICMP packet (inner packet) will be encapsulated using GRE.

GRE Encapsulation:

Outer IP Header:

Source IP:10.0.12.1 (R1 GE0/0/1 interface)

Destination IP:10.0.12.2 (R2 GE0/0/1 interface)

Inner IP Header:

Source IP:10.1.1.1 (Tunnel0/0/0 on R1)

Destination IP:10.3.1.1 (Tunnel0/0/0 on R2)

Theouter IP headeris used fortunnel routingbetween thephysical interfaces(GE0/0/1).

Theinner IP headerrepresents thelogical tunnel IPsused for communication between R1 and R2.

3. Correct Answer Analysis:

Option A:

Correct.

Theouter IP headeraddresses are10.0.12.1and10.0.12.2, representing thephysical interfaces (GE0/0/1)used to establish the tunnel.

Option C:

Correct.

Theinner IP headeraddresses are10.1.1.1and10.3.1.1, representing thelogical tunnel interfacesused for communication.

4. Why Other Options Are Incorrect:

Option B:

Incorrect.

Thedestination IP in the outer headershould be thepeer physical IP (10.0.12.2), not the tunnel IP (10.3.1.1).

Option D:

Incorrect.

Theinner IP destinationis thetunnel IP (10.3.1.1), not thephysical IP (10.0.12.2).

ForSRv6 (Segment Routing over IPv6)deployment on abearer WAN, the following are essential:

IGP (OSPFv3 or IS-IS): Required for SID advertisement and SRv6 route computation →✅

BGP: Required when deployinginter-domain SRv6or for control plane distribution of VPN/service routes →✅

Not required:

MPLS: SRv6 replaces MPLS labels withIPv6-based SIDs→❌

BGP-LU: Used inMPLS-based inter-AS scenarios,not applicableto SRv6 →❌

Correct answers: B, C

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.

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

Comprehensive and Detailed In-Depth Explanation:

OSPFv3, which supports IPv6, uses a router ID that is 32 bits in length, similar to OSPFv2. The router ID in OSPF is always a 32-bit number, typically represented in an IPv4 address format (dotted decimal). Although OSPFv3 is designed to support IPv6, itstill relies on a 32-bit router ID for identification, which must be unique within an OSPF domain. The router ID does not change even though the protocol itself supports IPv6 addresses (128 bits).