CCNP Architecture 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.

• ✓

  Provides predictable latency for east-west traffic.

  Why this is correct

  Correct. Spine-leaf provides predictable latency for east-west traffic because every leaf-to-leaf path crosses exactly one spine switch, giving a consistent hop count of two (leaf-to-spine-to-leaf) regardless of which leaf pair communicates. This uniform topology yields low, bounded, and predictable latency, unlike hierarchical designs where traffic may traverse multiple aggregation and core layers with variable distances. It is a key reason spine-leaf suits latency-sensitive data center applications.

• ✓

  Eliminates the need for spanning-tree protocol.

  Why this is correct

  Correct. Spine-leaf eliminates Spanning Tree Protocol (STP) by using Layer 3 routing between leaf and spine switches instead of Layer 2 bridging. Because every link is routed, Layer 3 protocols like BGP or OSPF perform loop prevention and fast failover, so STP's blocked ports and slow convergence are unnecessary. This also enables full utilization of all parallel links via ECMP, which STP would otherwise leave idle.

• ✗

  Reduces the amount of cabling required.

  Why it's wrong here

  Incorrect. Spine-leaf actually increases the amount of cabling required, not reduces it. In a spine-leaf design, every leaf switch must be physically connected to every spine switch to form a full mesh, resulting in N x M cable runs (where N is leaf count and M is spine count). This is a higher cable count than a traditional hierarchical design that aggregates uplinks, making cabling more extensive and structured, not less.

• ✓

  Simplifies scalability by adding leaf switches without redesign.

  Why this is correct

  Correct. Adding a leaf switch in a spine-leaf fabric is a simple horizontal scale-out operation: you only need to cable the new leaf to every spine switch and configure it with the same routing/overlay parameters. No redesign of the core or aggregation layer is required because the spine layer is stateless and forwards via ECMP based on destination prefixes. This modularity allows capacity to grow incrementally without impacting existing devices or traffic flows.

• ✗

  Eliminates the need for firewall appliances.

  Why it's wrong here

  Incorrect. Spine-leaf is a network fabric topology and does not replace security functions such as firewalls. Firewall appliances are still required to enforce security policies, segment workloads, and filter traffic between tenants or zones, whether deployed physically or virtually. The fabric's routing and connectivity patterns do not provide stateful inspection or access control, so firewall appliances remain a necessary component of a secure data center design.