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

OSPFv3 (used for IPv6) usesIPv6 multicast addressesfor 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 isnotapplicable 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

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.”

DiffServ QoS model operates on per-hop behavior (PHB) and has these limitations:

A. ✅ Single-hop behavior; no end-to-end path awareness.

B. ✅ Cannot guarantee dedicated resources to individual users.

C. ✅ Does not address traffic bursts; congestion is still possible.

D. ✅ Queue limitations hinder fine-grained SLA assurance and deterministic delay.

Exact Extract – HCIE-Datacom QoS Section:

“DiffServ provides PHB without path-level control. It cannot guarantee SLA for individual users due to limited queuing mechanisms and lack of end-to-end visibility.”