To build a loopless Layer 2 network, which of the following schemes is optimal?( Single Choice)

Stacking (such as Huawei's iStack or CSS) virtualizes multiple physical switches into a single logical switch. This fundamentally eliminates inter-switch loops, as the control plane sees them as internal backplane connections. Link aggregation bundles parallel links between the logical stack and other devices, preventing loops at the link level. This combination creates a highly resilient, loop-free Layer 2 topology that utilizes all available bandwidth without needing a protocol like STP to block redundant paths, making it the most optimal design.

B. TRILL is a replacement for STP, not a complementary protocol. Running both is redundant and complex, not optimal.
C. This option is incomplete. Assuming it implies using only MSTP, it is less optimal than stacking as MSTP must block redundant paths to prevent loops.
D. Link Aggregation combined with MSTP is a valid loop-prevention strategy, but it is suboptimal compared to stacking because MSTP will still block inter-switch links that are not part of an aggregate, reducing available bandwidth.

1. Huawei Enterprise Support, "HedEx V200R019C10, Configuration Guide - Ethernet Switching", Section: "Link Aggregation Configuration". This document explains how link aggregation bundles links to increase bandwidth and reliability, preventing loops between two connected devices.

2. Huawei Enterprise Support, "HedEx V200R019C10, Configuration Guide - Device Management", Section: "Stack Configuration". This guide details how stacking creates a single logical device, which inherently eliminates Layer 2 loops between the member switches.

3. Huawei Campus Switch Technology White Paper, "Huawei Campus Switch Stack Technology White Paper", Section 1.1 "What Is a Stack System?". It states, "A stack system improves switch reliability, simplifies network management, and simplifies the network topology. For example, a loop-free network can be established."