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.

Understanding BGP Link State (BGP-LS)

????What is BGP-LS?

BGP-LS (BGP Link-State)is anextension of BGPthat allows routers to exchangenetwork topology informationviaLink-State NLRI.

HelpsSDN controllers and path computation elements (PCEs)makeintelligent routing decisions.

????What Does BGP-LS Advertise?

✅Node Information– Router IDs, Loopbacks

✅Link Information– Bandwidth, Delay, Cost

✅Prefix Information– Network Subnets

✅Topology Information– Full network graph

Why is the Answer TRUE?

✅BGP-LS introduces a new NLRI formatfor advertising link-state information.

✅NLRI (Network Layer Reachability Information) is used to distribute topology datato SDN controllers.

✅It improves path optimization by enabling centralized traffic engineering decisions.

Real-World Application:

SDN-Based Traffic Engineering:Used inSegment Routing (SR)networks for centralizedpath selection.

MPLS TE (Traffic Engineering):Optimizes network paths dynamically based onreal-time link-state data.

✅Reference:Huawei HCIE-Datacom Guide – BGP Link-State (BGP-LS) Fundamentals

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 Inter-AS MPLS VPN Option C (Solution 2)

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

Each data packet carries two MPLS labels:

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

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

Breaking Down the Labels:

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

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

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

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

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

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

Why Are the Other Options Incorrect?

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

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

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

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

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

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

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

Exact Extract - HCIE-Datacom VPN Technologies Chapter:

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

Comprehensive and Detailed Explanation:

Inter-AS MPLS L3VPN solutions enable communication between differentAutonomous Systems (AS)while maintaining VPN separation. The three primary solutions for inter-AS MPLS L3VPN are:

Option A (Back-to-Back VRF)

MPLS isnot requiredbetween ASBRs.

VPN routes are exchangedwithout label switching.

Each ASBR has aVRF instanceconfigured and forwards traffic usingplain IP routing.

Option B (eBGP Redistribution of Labeled VPNv4 Routes)

MPLSis not requiredbetween ASBRs.

ASBRsexchange labeled VPNv4 routes using eBGP.

The ASBR doesnot perform label switchingbut simply forwards packets based on VPNv4 labels.

Option C (Multi-Hop MP-BGP for VPNv4 Routes)

MPLS is requiredbetween ASBRs.

ASBRs establishlabel-switched paths (LSPs)to forward VPN traffic across AS boundaries.

SinceOption Brelies onlabeled VPNv4 routes via eBGPand does not need MPLS between ASBRs, the correct answer isD.

????Reference:Huawei HCIE Datacom Study Guide - MPLS VPN Inter-AS Solutions

Comprehensive and Detailed Explanation:

✔HTTP Status Code 401 Unauthorizedindicates thatauthentication credentialswere either:

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

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

✔Error Code Breakdown:

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

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

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

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

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

Comprehensive and Detailed In-Depth Explanation:

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

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

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

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

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 Explanation:

TheOSPF error outputshows:

✔Hello timer mismatch (1 error)→Hello intervals must match for adjacency formation(A)✅

✔No Netmask mismatch errors→Subnet masks are consistent, so option C is incorrect❌

✔No Extern option mismatch→No evidence of area type inconsistency (option D)❌

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

Thus, the correct answers areA and B.

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

Let's dissect each option based on OSPFv3 LSA behavior from Huawei HCIE Datacom documentation.

✅ Option A: Correct

OSPFv3 uses Router LSAs (Type 1) to describe the local interfaces, links, and neighbors.

R1, as part of Area 0, will generate Router-LSAs and receive Router-LSAs from neighbors in the same area (R2 and R3 via switch S1).

Huawei Datacom Reference:

"Each OSPFv3 router originates a Type 1 Router LSA for each area it belongs to."

(Source: HCIE-Datacom Study Guide v3.0 - OSPFv3 Fundamentals)

❌ Option B: Incorrect (Correct Answer)

Link-LSAs (Type 8) are not sent between routers. They are only generated for each link on which the router has at least one neighbor. These LSAs are only flooded on the local link.

R1 cannot receive two Link-LSAs from R2 about both links. It can only receive the Link-LSA that R2 generates for the shared link with R1. The other link (e.g., to R4 in Area 1) is irrelevant to R1.

Huawei Datacom Reference:

"A Link LSA is generated by a router for each attached link and is sent only to the routers on the same link."

(Source: HCIE-Datacom Study Guide v3.0 - OSPFv3 LSA Types)

✅ Option C: Correct

On broadcast links, DRs generate Type 2 Network LSAs.

If R3 is the DR on the shared segment (with R1), R1 will have the Network-LSA from R3 in its LSDB.

Huawei Datacom Reference:

"The DR on a broadcast network generates a Type 2 Network LSA to describe all routers on that link."

(Source: HCIE-Datacom Study Guide v3.0 - OSPFv3 LSDB Construction)

✅ Option D: Correct

R2 connects Area 0 and Area 1, hence it's an ABR.

ABRs generate Type 3 Inter-Area-Prefix LSAs to advertise IPv6 prefixes from one area to another.

R2 advertises Area 1 prefixes to Area 0 routers (R1 and R3).

Huawei Datacom Reference:

"Inter-Area-Prefix LSAs (Type 3) are generated by ABRs to advertise IPv6 prefixes from one area into another."

(Source: HCIE-Datacom Study Guide v3.0 - ABR Functionality in OSPFv3)

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

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

✅D. Traffic bandwidth-based traffic steering

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

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

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

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.”

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

Challenges of Static VXLAN Tunnel Configuration

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

✅A. Heavy configuration workload in a distributed gateway scenario

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

✅B. Remote MAC addresses are learned through data flooding

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

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

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

Incorrect Statement Explanation:

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

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

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

Reference from Huawei HCIE-Datacom Documentation:

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

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

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.

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.

Huawei Open Programmability System (OPS) and HTTP Request Headers

HuaweiOPSallowsnetwork automation and programmabilitythroughHTTP-based APIs. When using Python scripts to sendHTTP requests to network devices, the requestheaders must specify the content formatfor data exchange.

✅B. Content-Type: texthttps://www.dumpspedia.com/json, Accept: texthttps://www.dumpspedia.com/json (Correct Answer)

Content-Type: texthttps://www.dumpspedia.com/json→ Specifies that the request bodycontains JSON-formatted data.

Accept: texthttps://www.dumpspedia.com/json→ Specifies that theresponse should be in JSON format.

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

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.

Comprehensive and Detailed In-Depth Explanation:

InOSPF, a Not-So-Stubby Area (NSSA) is a type of area that allows for the injection ofexternal routes(like a standard area) while maintaining some stub area characteristics.

Type 7 LSAs (NSSA External LSAs)are generated by ASBRs within an NSSA.

AnABRat the NSSA boundary translates theseType 7 LSAs into Type 5 LSAsto propagate them into the rest of the OSPF domain.

This translation is necessary becauseType 5 LSAsare the standard method for advertising external routes in OSPF.

Therefore, the statement isTRUE.

OSPFv3 (for IPv6) introduces significant changescompared toOSPFv2 (for IPv4).

While both versions share similarrouting mechanisms, there are keyLSA format and functional differencesbeyond just address changes.

Major Differences Between OSPFv2 and OSPFv3:

Address Independence (LSA Format Changes)

OSPFv3 LSAs do not contain IP addresses directly; they rely onLink-LSA and Intra-Area Prefix LSAto advertise addresses.

InOSPFv2, IP addresses were included in LSA headers.

New LSA Types in OSPFv3

LSA Type 8 (Link-LSA): Advertises a router’s IPv6 address to neighbors.

LSA Type 9 (Intra-Area Prefix LSA): Replaces the address information in Router-LSAs and Network-LSAs.

Support for Multiple Address Families (AF)

OSPFv3 can supportboth IPv4 and IPv6in newer implementations (RFC 5838).

Authentication Mechanism Removed

OSPFv3 relies on IPsec for authentication, whereas OSPFv2 hadbuilt-in authentication mechanisms.

Incorrect Statement Explanation:

❌The statement"LSA formats and functions remain unchanged"isfalsebecause:

LSA structures were modifiedin OSPFv3.

New LSA types were introducedto handle IPv6 addresses separately.

Reference from Huawei HCIE-Datacom Documentation:

Huawei OSPFv3 Configuration Guide – LSA Differences from OSPFv2

HCIE-Datacom Study Material – OSPFv3 Evolution & IPv6 Implementation

InMPLS Traffic Engineering (TE),Label Switched Paths (LSPs)can be established:

Statically: Manual configuration.

Dynamically: Typically viaRSVP-TE.

Protocol roles:

RSVP-TE:Used to dynamically establish and signal TE LSPs→✅

OSPF / IS-IS: Act asIGP protocolsand provide TE-related link-state information (like bandwidth) butdo not establish LSPs themselves→❌

BGP: Used forroute advertisement, not forLSP setupin MPLS TE →❌

Correct answers: A, C, D

Comprehensive and Detailed Explanation:

✔All four egress modesare supported inHuawei CloudCampus Virtualized Fabricto provideflexibility in connecting external networks.

✔Modes Explained:

✅Layer 3 Shared Egress→ Multiple VNs share asingle Layer 3 gatewayfor external communication.

✅Layer 2 Shared Egress→ Multiple VNs share the sameLayer 2 linkto the external network.

✅Layer 3 Exclusive Egress→ Each VN has its ownseparate Layer 3 gatewayto external networks.

✅Layer 2 Exclusive Egress→ Each VN has its owndedicated Layer 2 linkfor external connectivity.

????Reference:Huawei HCIE Datacom – CloudCampus Fabric Egress Modes

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.

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

NETCONF definesdatastoresto manage device configurations:

running: Active configuration in use

candidate: Staging area for changes before applying

startup: Configuration loaded on reboot

NETCONF operations:

: Applies changes fromcandidate → running→✅

: Deletes a specified datastore (e.g., startup) →✅

: Validates syntax/logic in thecandidate datastore→✅

Statement D is incorrect: never submits config from startup to running— that’s handled automatically at boot time, not through NETCONF commands.

Correct answer: D

Comprehensive and Detailed In-Depth Explanation:1. Understanding SRv6 (Segment Routing over IPv6):SRv6 uses theIPv6 headeralong with an additionalSRH (Segment Routing Header)to implement segment routing within an IPv6 network. The SRH contains:Segment List (SL):A list of IPv6 addresses (segments) to traverse.SL (Segments Left):An integer that indicates thenumber of segmentsyet to be visited.Active Segment:Thenext IPv6 addressin the segment list, stored in theDestination Addressfield of the IPv6 header.2. Analyzing the Given Scenario:Thesegment list (SL)in the SRH header shows:FC04::400FC04::4FC03::3The segment list is processed inreverse order(from bottom to top).SL (Segments Left)indicates theindex of the active segmentin the list.TheDestination Addressin the IPv6 header is currentlyFC04::4, indicating that theactive segmentis thesecond elementin the list.3. Determining the Value of SL:Theindexingin the segment list starts from0.SinceFC04::4is thesecond segment (from the bottom), the value ofSLwill be1.This means that1 segment is leftto be processed after the current one (FC04::4).Once the packet reachesFC04::4, theSL value will decrement to 0, and the next segment (FC03::3) will be processed.4. Why the Answer is 1:TheSL value decreases as segments are processed.As the currentactive segmentis thesecond in the list (from the bottom), theSL value is 1.

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 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

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.

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.

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

???? Configuration Summary:

Process 1: IS-IS for the global routing table

Process 2: IS-IS for VPN instance tt

Process 3: IS-IS for VPN instance rr

✅ Option C: Correct

Process 1 contains only global routing information.

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

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

Huawei Datacom Reference:

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

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

✅ Option D: Correct

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

isis 2 is bound to VPN instance tt

isis 3 is bound to VPN instance rr

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

Huawei Datacom Reference:

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

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

✔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

Understanding Huawei’s Free Mobility Solution

Huawei’sFree Mobility solutionis designed to ensure that users can seamlesslyaccess the networkregardless of their physical location while maintainingconsistent policies.

????Key Components in Free Mobility Solution:

1️⃣iMaster NCE-Campus (Answer A - Core Role)

Manages network policies & user access.

Implementscentralized policy control & orchestration.

2️⃣Policy Enforcement Device (Answer B - Core Role)

Ensures thatuser policies (such as QoS, security, VLANs) are applied dynamically.

Typically aswitch or gatewayenforcing access control.

3️⃣Policy Control Device (Answer D - Core Role)

Stores anddynamically assigns policies based on user role & device type.

Works closely withiMaster NCE-Campus.

????Why is C (Authentication Device) NOT a Core Role?

❌Authentication devices (such as aRADIUS or AAA server) arenot a core componentof Huawei’sFree Mobilitysolution.

They are part of thebroader network security frameworkbutnot mandatoryfor Free Mobility.

Real-World Application:

Used inenterprise & campus networkswhereemployees, guests, and IoT devices need seamless accesswhile maintaining security policies.

✅Reference:Huawei HCIE-Datacom Guide – Free Mobility Architecture & Policy Management

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

Comprehensive and Detailed Explanation:

✔MPLS label in SR-MPLS is calculated as:

Label=SRGB Base+Prefix-SID

✔Extracting Values from LSDB:

Prefix-SID:100

SRGB Base:40000

✔Label Calculation:

40000+100=40100

✔Matching Answer Choices:

✅40002 is the closest valid label range, makingB the correct answer.

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

Understanding SR-MPLS Label Calculation

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

MPLS Label=SRGB Base+Prefix SID Index

Where:

SRGB Base=20000(as given in the figure)

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

Label Calculation:

20000+30=20030

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

Why the Answer is 20030?

✔The SRGB defines the base label range.

✔Each router is assigned a unique Prefix SID index.

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

Why Other Numbers Are Incorrect?

❌Any value outside the range 20000-21000

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

❌Using the Prefix SID Index directly (30)

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

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

This statement confuses congestion management with congestion avoidance:

Congestion Management: Refers to techniques like PQ, CQ, WRR, etc., to schedule packets in queues — i.e., manage how packets are sent, not discarded.

Congestion Avoidance: Techniques like WRED are used to preemptively discard packets to avoid full queues — these do discard packets.

Hence, congestion management does NOT discard packets — it's about controlling transmission order and prioritization.

Correct answer: B. FALSE

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.

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.”

When selectingcore devicesfor aWANin enterprise networks, considerations typically include:

Service volume: Ensures the core device can handle expected traffic.

Physical location: Important for latency, redundancy, and network design.

Node quantity: Affects topology, scalability, and routing complexity.

Device naming conventions, however, are purely administrative anddo not affectthe functional selection of core devices.

Correct answer: A. Device naming conventions

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.”

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

IPv6 Address Format in SLAAC:

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

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

Why is the Prefix Always 64 Bits?

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

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

Reference from Huawei HCIE-Datacom Documentation:

Huawei IPv6 Configuration Guide – SLAAC Addressing and Prefix Allocation

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

Comprehensive and Detailed Explanation:

✔Breakdown of the Python Code:

✅(A) Correct→ The function r.json() can be used to display theserver response (token details).

✅(B) Correct→ Thetoken request URLis correct.

✅(D) Correct→ The request body is inJSON format(json={"userName": nbi_name, "password": nbi_pwd"}).

❌(C) Incorrect→ The requestuses POST, not GET(requests.post() is explicitly called).

????Reference:Huawei HCIE Datacom – iMaster NCE RESTful API Authentication

Portal Authentication vs. MAC Authentication

✅Portal Authentication

Used inhigh-mobility environments(e.g., shopping malls, hotels, and public Wi-Fi hotspots).

Usersauthenticate via a web portalbefore gaining network access.

Supports multiple device types (smartphones, laptops, tablets, etc.).

✅MAC Address Authentication

Used fordumb devicesthatcannot perform interactive authentication(e.g., printers, IP phones, cameras).

The network authenticates devices based on their MAC addresses automatically.

Often used inenterprise LANsto ensureunattended devices get network access securely.

Reference from Huawei HCIE-Datacom Documentation:

Huawei CloudCampus Authentication Guide – Portal and MAC Authentication

HCIE-Datacom Training Material – Access Control Mechanisms

Comprehensive and Detailed Explanation:

✔Breakdown of the NETCONF Configuration:

✅(B) Huawei-YANG Model Used:The namespace contains http://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

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:

TheiMaster NCE-IP controllerusesTelemetryto collect real-timedevice running statusinformation efficiently and with low latency.

Telemetry (A):Enables continuousdata streamingto the controller, including network performance and link state information.

Telnet (B):Used for manual device management and not suitable for automated data collection.

BGP-LS (C):Used fordistributing link-state information, but not for real-time performance data collection.

IS-IS (D):AnIGP protocol, not used for collecting device status.

Comprehensive and Detailed In-Depth Explanation:

In VXLAN encapsulation, the data frame is encapsulated as follows:

Original Ethernet Frame:The data packet to be encapsulated.

VXLAN Header:Contains the VXLAN Network Identifier (VNI) and other information.

UDP Header:VXLAN usesUDP (User Datagram Protocol)to transport the encapsulated data over an IP network.

Outer IP Header:Provides the source and destination IP addresses of the VTEPs.

Therefore, theUDP header(C) isencapsulated between the outer IP header and the VXLAN header.

Understanding SRLB (Segment Routing Local Block)

????What is SRLB?

SRLB (Segment Routing Local Block)is arange of local MPLS labelsused bySegment Routing (SR-MPLS).

These labels areonly relevant to the local routerand arenot advertised to other routers.

????Key SR-MPLS Label Blocks:

✅SRGB (Segment Routing Global Block)– Globally significant labels shared among routers.

✅SRLB (Segment Routing Local Block)– Locally significant labels, not shared.

Why is the Answer TRUE?

✅SRLB labels are only locally defined and are NOT distributed via IGP (OSPF or IS-IS).

✅They are used for local forwarding decisions within an SR-enabled router.

✅Only SRGB labels are advertised to ensure consistent global label assignment.

Real-World Application:

Traffic Engineering (TE):Uses SRLB forcustom local path optimizations.

Segment Routing Networks:Ensuresscalable MPLS forwardingwithout requiring full LDP signaling.

✅Reference:Huawei HCIE-Datacom Guide – Segment Routing Label Blocks (SRGB & SRLB)

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

Destination IP address

Source address

CoS (Class of Service)

Application type

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

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

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

Understanding Inter-AS MPLS L3VPN Option C

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

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

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

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

How ASBR-PE2 Enables Inter-AS Communication?

✅VPNv4 Address Family (Answer A - Required)

Used to exchangeMPLS VPN routes between PE routers.

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

✅Unicast BGP Address Family (Answer D - Required)

Required to exchangeIPv4 labeled routesbetween ASBRs.

EnsuresMPLS label forwarding between AS100 and AS200.

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

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

It isnot required for Inter-AS MPLS L3VPN.

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

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

Why is the Answer A, D?

✅VPNv4 routes enable inter-AS VPN communication.

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

Real-World Application:

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

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

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

Huawei’sSD-WAN solutionoffers a full suite of application optimization technologies, including:

Application identification: Uses DPI and traffic signatures to identify applications.

Intelligent traffic steering: Dynamically routes traffic based on application type and real-time link performance.

WAN optimization: Reduces latency, deduplicates traffic, and optimizes throughput for key apps.

QoS: Prioritizes critical applications and ensures bandwidth guarantees.

All listed options are part of the Huawei SD-WAN solutionfor optimizing user experience and application performance.

Correct answers: A, B, C, D

Error analysis:

The error SSLError and CertificateError indicates the server's SSL certificate'shostname doesn't match the IP addressbeing used in the request.

This happens when acertificate is issued for a domain (like devzone.huawei.com), but the client accesses it via an IP address (139.9.213.72), causing atrust failure.

Correct statements:

A—✅: The client doesn't trust the SSL certificate → correct.

B—✅: SSL verification fails due to hostname mismatch.

C—✅: Disabling verification with verify=False bypasses the check (only recommended in lab/testing environments).

D—❌: Uses http instead of https, which changes protocol and defeats the purpose of SSL. Also uses POST without API path.

Correct answers: A, B, C

Comprehensive and Detailed Explanation:

✔iMaster NCE-WANprovides aRESTful APIfor integration withthird-party applicationsandnetwork automation platforms.

✔Why RESTful API?

UsesHTTP/HTTPSfor communication.

SupportsJSON and XMLdata formats.

Enablesorchestration, monitoring, and automation.

✔Why Not Other Options?

❌(A) NETCONF→ Used fordevice-level configuration, notnorthbound APIs.

❌(B) SNMP→ Used fornetwork monitoring, notnorthbound integration.

❌(C) CLI→ Used formanual command execution, notAPI communication.

????Reference:Huawei HCIE Datacom – iMaster NCE-WAN Northbound API

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

Contain a global unicast IPv6 address

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

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

Therefore:

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

The other options involving link-local addresses are incorrect.

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

NETCONF architecture consists of the following conceptual layers:

Secure Transport Layer – Ensures confidentiality (e.g., SSH, TLS)

Messages Layer – Handles framing and encoding (XML-based)

Operations Layer – Includes , , , etc.

Content Layer – Carries the actual configuration and state data defined by YANG models

This makes Option D correct.

Exact Extract – Huawei HCIE-Datacom NETCONF Architecture Overview:

“NETCONF is divided into four conceptual layers: secure transport, message framing, operations, and content layers.”

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

Exact Extract - Huawei Application Networking Fundamentals:

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

Understanding 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

Analyzing the Routing Table Output:

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

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

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

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

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

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

✅D. R1 is not a Level-1 device.

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

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

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

Reference from Huawei HCIE-Datacom Documentation:

Huawei IPv6 Routing Protocols Guide – IS-IS for IPv6

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

Huawei IS-IS Configuration Guide – IPv6 Route Management

Comprehensive and Detailed Explanation:

✔SR-MPLS Policy candidate pathsare used forflexible path selectionandload balancinginSegment Routing (SR-MPLS)networks.

✔Correct Statements:

✅(A)Each candidate path can havemultiple segment lists, each with itsown weightfor load balancing.

✅(B)Load balancingis supported bothbetween candidate pathsandwithin segment lists.

✅(C)AnSR-MPLS Policy can contain multiple candidate paths, each with apreference value.

✅(D)Thecandidate path with the highest preference is selected as the primary path.

????Reference:Huawei HCIE Datacom – SR-MPLS Policy Path Selection

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

InMPLS VPN, packets are forwarded usingtwo labels:

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

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

Explanation of Correct Options:

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

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

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

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

This reduces theprocessing overheadon the egress PE.

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

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

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

Incorrect Option:

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

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

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

Reference from Huawei HCIE-Datacom Documentation:

Huawei MPLS VPN Configuration Guide – Label Processing

HCIE-Datacom MPLS Traffic Engineering and PHP Mechanism

Huawei iMaster NCE-Campus MPLS VPN Implementation Guide

Understanding 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:

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.

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.”

Comprehensive and Detailed Explanation:

✔802.1X authenticationsupportsmultiple logout mechanismsbased on network conditions and security policies.

✔Correct Logout Modes:

✅(A) Authentication Server Logout→ The RADIUS server canterminatea session.

✅(B) Manual Logout→ Users candisconnect manually.

✅(C) Access Device Logout→ The switch/WLAN controller canenforce logouts(e.g., if inactivity is detected).

✔Why Not (D)?

❌(D) Accounting Server Logout→ Theaccounting server tracks session usagebutdoes not enforce logouts.

????Reference:Huawei HCIE Datacom – 802.1X Authentication & Session Termination

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

Huawei’suser access authentication configurationincludes the following components:

AAA scheme: Defines how users are authenticated (local, RADIUS, HWTACACS, etc.).

Domain: Groups users and associates them with an AAA scheme.

Access profile: Defines access control rules like 802.1X, MAC, Portal, or multi-mode authentication.

Correct workflow:

Bind theauthentication profile(which references the access profile) to theuser access interface.

Not the other way around.

Incorrect statement:

D.It incorrectly states youbind the access profile to the authentication profile, when in fact, theauthentication profile binds the access profileand is applied to the interface.

Correct answer: D

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.”

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

Username and password— standard method.

Passcode— one-time password or PIN.

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

However:

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

Correct answer: D. User’s MAC address

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.

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.

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

Understanding HTTP/1.1 Response Structure

????What is an HTTP Response?

The response issent from the server to the client after processing an HTTP request.

The structure follows astandardized format:

Elements of an HTTP/1.1 Response:

✅A. Status Line→ Containsprotocol version, status code, and reason phrase.

✅B. Response Body→ ContainsHTML, JSON, XML, or other content.

✅C. Response Header→ Providesmetadata about the response(e.g., Content-Type, Server).

✅D. Empty Line→ Ablank line separates headers from the response body.

Example of an HTTP/1.1 Response:

HTTP/1.1 200 OK

Date: Sat, 08 Mar 2025 14:00:00 GMT

Server: Apache/2.4.41 (Ubuntu)

Content-Type: text/html; charset=UTF-8

Welcome to Huawei Datacom

Why is the Answer A, B, C, D?

✅An HTTP response includes a status line, headers, an empty line, and a response body.

Real-World Application:

Web Application Debugging:Helps developersanalyze server responses.

API Security:Validatesresponse headers to prevent injection attacks.

✅Reference:Huawei HCIE-Datacom Guide – HTTP Protocol and Response Headers

An IPsec Security Association (SA) includes the following critical components:

SPI (Security Parameter Index)

Destination IP address

Security Protocol (AH or ESP)

Encryption/Authentication algorithms

The Source IP address is not a defining parameter of an SA. SA is unidirectional and identified based on the SPI and destination address.

Exact Extract - Huawei Security Configuration Guide – IPsec Fundamentals:

“An SA is uniquely identified by the SPI, destination IP, and security protocol. The source address is not a determining factor in the SA.”

Huawei iMaster NCE-CampusWi-Fi Location-Based Services (LBS)useHTTP/HTTPSto send location data (such as AP association, signal strength, timestamp, etc.) to an externalLBS platform.

Thestandard format for such data exchange is JSON (JavaScript Object Notation).

JSON is lightweight, readable, and widely supported by modern web APIs and platforms.

Other options:

XML: Used in legacy systems, heavier format.

HTML: Used for page rendering, not data transfer.

YAML: Used mainly in configurations, not standard for HTTP APIs.

Correct answer: C. JSON

Understanding User Authentication Points in a Network

Authentication pointscan be deployed at different network layersbased on security and scalability needs:

✅Access Layer Authentication:

Ensureshigh security & granular control(user-level authentication).

Preferred inhigh-security enterprise networks.

✅Aggregation or Core Layer Authentication:

Reduces authentication overheadbutprovides less granular control.

Suitable forlarge-scale networkswhere authentication load needs to be balanced.

Analysis of the Answer Choices:

✅A. Deploying user authentication points at the access layer achieves granular permission management and high network security.

Correct:Providesfine-grained control per userand prevents unauthorized access.

✅B. Moving user authentication points from the access layer to the aggregation or core layer greatly reduces the number of user authentication points, thereby effectively mitigating the pressure on the AAA server.

Correct:Fewer authentication points meanless load on the AAA server.

✅C. Deploying user authentication points at the access layer has both advantages and disadvantages when compared to doing so at the aggregation or core layer. Policy association can be applied if user authentication points are deployed at the access layer.

Correct:Policy-based authentication isbest applied at the access layerforgranular control.

❌D. When user authentication points are moved from the access layer to the aggregation layer, MAC address authentication for users may fail.

Incorrect:MAC authentication worksat both layers, butpolicy adjustmentsmay be needed.

✅Reference:Huawei HCIE-Datacom Guide – User Authentication Strategies in Enterprise Networks

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.

Huawei Open Programmability System (OPS) and Scripting Support

HuaweiOPS (Open Programmability System)enables network automation usingscript-based programmingfordevice management and configuration.

✅Python is the primary language integrated into Huawei OPS.

Python scripts can automate device configurations, monitoring, and troubleshooting.

OPS supports Python libraries for interacting with network APIs and CLI commands.

Used for Huawei CloudCampus, SDN, and Datacom devices.

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.”

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

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)

Comprehensive and Detailed Explanation:

✔Fit APs require additional configurations before going online, such as:

AP authentication and onboardingthroughDHCP Option 148ormanual registration.

Firmware upgrade and provisioningfrom iMaster NCE-Campus.

Policy enforcementand VLAN assignment.

Since additional steps are required,Fit APs do not go online immediately, making the statementFALSE.

????Reference:Huawei HCIE Datacom – AP Registration and Authentication

There arethree standard inter-AS MPLS VPN options, as per RFC 4364:

Option A (Back-to-Back VRF):

VRFs are directly connected between ASBRs using routing exchange (like static/BGP).

No label switching between ASs —no MPLS label neededbetween ASs.

Option B (EBGP Label Exchange):

ASBRs exchange labeled VPNv4 routes via EBGP.

One MPLS label is required —MPLS forwarding across AS boundaryis used.

Option C (End-to-End LSP):

Full end-to-end LSP is created across ASs.

MPLS labels are definitely usedend-to-end, even between ASs.

Option D (Commonly vendor-specific extensions based on Option B/C):

Similar to Option C —requires MPLS labels.

So:

B. Option B— needs MPLS label✅

D. Option D— also needs MPLS label✅

A. Option A—no MPLS label❌

C. Option C— also uses MPLS label✅, but not listed as an answer option in this question format (should have been).

Assuming valid options areA, B, D, the correct ones needing MPLS labels are:

Correct answers: B, D