H12-891_V1.0 Exam Dumps - HCIE-Datacom V1.0

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.

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

Exact Extract – Huawei SR-MPLS Configuration Guide:

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

VXLAN networks suffer from ARP flooding because ARP requests are broadcasted across all VTEPs in a Layer 2 domain. To reduce 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 VTEP caches MAC-IP mappings and replies directly to ARP requests, reducing unnecessary flooding.

✅ B. ARP Broadcast Suppression

Converts ARP broadcast packets into unicast or multicast packets to 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 VLAN but does not help reduce ARP flooding between VTEPs.

Reference from Huawei HCIE-Datacom Documentation:

Huawei VXLAN Configuration Guide – ARP Optimization Techniques

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

Huawei Open Programmability System (OPS) and HTTP Request Headers

Huawei OPS allows network automation and programmability through HTTP-based APIs. When using Python scripts to send HTTP requests to network devices, the request headers must specify the content format for data exchange.

✅ B. Content-Type: text/json, Accept: text/json (Correct Answer)

Content-Type: text/json → Specifies that the request body contains JSON-formatted data.

Accept: text/json → Specifies that the response should be in JSON format.

OSPFv3 Configuration Principles:

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

Interface-based Configuration:

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

Router ID:

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

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

Analysis:

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

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

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

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

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

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

D. [R1] router id 10.1.1.1:

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

Therefore, the correct answers are A and B.