200-901 Designing a new branch network Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✗

  Spanning Tree Protocol

  Why it's wrong here

  Spanning Tree Protocol prevents Layer 2 loops by blocking redundant paths, but it does not partition a network into separate broadcast domains. It is tempting because it is a standard switch feature for stable topologies, and would be correct when eliminating bridging loops, not when segmenting broadcast traffic for security.

• ✗

  Subnetting

  Why it's wrong here

  Subnetting partitions a network into IP subnets, but each subnet still forms one broadcast domain unless a router or VLAN separates them; it does not itself create separate broadcast domains. It is tempting because subnetting is used for addressing and segmentation, and would be correct when dividing address space rather than isolating broadcast traffic.

• ✗

  EtherChannel

  Why it's wrong here

  EtherChannel bundles multiple physical links into one logical link for increased bandwidth and redundancy, but all member links remain in the same broadcast domain. It is tempting because it is a common branch-network design choice, and would be correct when link aggregation or fault tolerance is required, not broadcast-domain separation.

• ✓

  VLANs

  Why this is correct

  VLANs logically partition a single physical switch into isolated Layer 2 segments, each forming its own broadcast domain. This directly satisfies the requirement to separate broadcast domains, cutting broadcast traffic and enforcing segmentation between groups without additional hardware.