Ace Your H12-891_V1.0 HCIE-Datacom Exam

The Protocol Trace function of iMaster NCE-CampusInsight allows O & M teams to analyze the full packet exchange process (e.g., DHCP, authentication, IP acquisition) between clients and the network. In this scenario, it helped pinpoint DHCP address pool exhaustion as the cause.

Exact Extract - Huawei iMaster NCE-CampusInsight Product Documentation:

“The Protocol Trace function visualizes packet-level interaction processes for DHCP, ARP, 802.1X, and others, allowing fast identification of root causes for network access issues.”

In MPLS (Multiprotocol Label Switching), Label Switching Routers (LSRs) handle packets based on FECs (Forwarding Equivalence Classes) and their positions in the label-switched path:

Ingress LSR: The entry point for labeled packets; it classifies packets into FECs and assigns the initial label.

Transit LSR: Intermediate routers that swap labels and forward packets along the LSP.

Egress LSR: The last router in the LSP that removes the label and forwards the packet normally.

An LSR cannot be both an ingress and a transit router for the same FEC, because an ingress LSR is defined as the starting point for that specific FEC ' s LSP. If it’s the ingress, it means the labeled path starts there, so it can ' t be in the middle (transit) of that same path.

Therefore, the statement is FALSE.

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.”

In SR-MPLS (Segment Routing over MPLS), prefix SID conflicts may occur if multiple prefixes are assigned the same SID or vice versa.

Conflict resolution principle (Huawei standard):

When there are multiple SIDs for the same prefix, the SID with the lowest value wins.

When the same SID is assigned to multiple prefixes, the prefix with the smallest address wins.

Apply to this case:

Conflict: Two entries for 1.1.1.1/32 with SID 2 and SID 1.

SID 1 is lower, so 1.1.1.1/32 → SID 1 is selected.

Correct answer: D. 1.1.1.1/32 → SID 1