Pass the Huawei HCIE-Datacom H12-891_V1.0 Questions and answers with CertsForce

Telemetry Data Collection in Huawei Devices

Telemetry allows real-time streaming of network performance data based on predefined sampling paths. Supported sampling paths include:

✅ A. Interface statistics

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

✅ C. CPU information

Tracks CPU utilization and performance metrics.

✅ D. Memory information

Monitors RAM usage and system memory consumption.

Incorrect Answer:

❌ B. Information about the optical module on an interface

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

Reference from Huawei HCIE-Datacom Documentation:

Huawei Telemetry Configuration Guide – Supported Sampling Paths

HCIE-Datacom Study Material – Network Performance Monitoring with Telemetry

OSPFv3 (used for IPv6) uses IPv6 multicast addresses for communication between routers:

FF02::5 — All OSPF routers.

FF02::6 — All OSPF Designated Routers (DRs) and Backup Designated Routers (BDRs).

FF08::x — These are used for organization-local scope, which is not applicable to standard OSPFv3 operation.

Therefore:

C. All OSPF routers use FF02::5 — Correct

D. The DR uses FF02::6 — Correct

A and B (FF08::x) — Incorrect. These addresses are not used by OSPFv3 in this context.

Correct answers: C and D

According to the displayed OSPF error statistics from the Huawei device, the key HELLO packet error shown is:

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2 : Netmask mismatch

This indicates that the OSPF adjacency formation is failing due to a subnet mask mismatch between the two OSPF neighbors on the corresponding interface (GigabitEthernet 0/0/0). OSPF uses the subnet mask in Hello packets to ensure that neighbors are in the same network. If the masks do not match, OSPF will not form an adjacency.

From the Huawei Official HCIE-Datacom Study Guide (Version 3.0) — under the OSPF Troubleshooting Section:

" Netmask mismatch: If the subnet mask configured on the interfaces of OSPF neighbors does not match, a ' Netmask mismatch ' error occurs. OSPF requires neighbors to be on the same subnet to establish an adjacency. This is a common reason for failure in adjacency formation. "

(Reference: Huawei HCIE-Datacom V3.0, OSPF Troubleshooting Chapter, Section 4.2 – OSPF Hello and Adjacency Establishment Issues)

Thus, among the given options:

A. Area type inconsistency would result in an area ID mismatch error, not netmask.

B. Authentication mismatch would show a bad authentication key or type error.

D. Hello interval mismatches would trigger a Hello timer mismatch error.

Only C. The IP address masks of the interfaces are inconsistent directly matches the actual error observed: Netmask mismatch.

Comprehensive and Detailed Explanation:

✔ All four egress modes are supported in Huawei CloudCampus Virtualized Fabric to provide flexibility in connecting external networks.

✔ Modes Explained:

✅ Layer 3 Shared Egress → Multiple VNs share a single Layer 3 gateway for external communication.

✅ Layer 2 Shared Egress → Multiple VNs share the same Layer 2 link to the external network.

✅ Layer 3 Exclusive Egress → Each VN has its own separate Layer 3 gateway to external networks.

✅ Layer 2 Exclusive Egress → Each VN has its own dedicated Layer 2 link for external connectivity.

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

Correct Matching of Authentication Methods:

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

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

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

Understanding Network Admission Control (NAC) Authentication Methods

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

???? Different types of devices require different authentication methods based on capabilities and security requirements.

Analysis of Each Authentication Type:

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

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

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

Provides strong security using EAP (Extensible Authentication Protocol) over RADIUS.

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

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

Uses MAC addresses as identity credentials.

Suitable for VoIP networks, industrial IoT, and surveillance cameras.

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

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

Redirects users to a web-based login page before granting access.

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

Why These Assignments Are Correct?

1️⃣ 802.1X for PC:

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

Ensures high security by verifying user credentials.

2️⃣ MAC Address Authentication for IP Phone:

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

Simplifies authentication while maintaining security.

3️⃣ Portal Authentication for Wireless Clients:

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

Common in enterprise guest Wi-Fi and public hotspots.

Real-World Application:

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

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

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

Comprehensive and Detailed In-Depth Explanation:

Analyzing the output:

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

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

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

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

Therefore, the correct answer is D because the tunnel does not have keepalive enabled.

✔ Egress devices in Huawei CloudCampus static IPsec VPN include:

Access Points (APs)

Routers

Firewalls ✅

✔ Why Firewalls?

Firewalls support IPsec VPN termination for secure WAN interconnection.

Firewalls provide advanced security filtering and encryption for IPsec traffic.

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

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

In BGP EVPN configuration for VXLAN-based networks, Huawei uses the command:

[bgp] advertise l2vpn evpn

This command enables the BGP process to advertise routes from a VPN instance into the EVPN (L2VPN) address family, which is used for VXLAN control-plane operations like MAC/IP advertisement.

Option A (advertise irbvfi) — invalid command.

Option B (advertise vpnv4) — used for MPLS VPNs, not EVPN.

Option C (advertise irb) — not a recognized Huawei command.

Option D is the correct and officially used command.

Correct answer: D. advertise l2vpn evpn