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Objective 1.2

200-301

Describe characteristics of network topology architectures.

Objective 1.2 sits in Network Fundamentals, which carries 20% of the CCNA exam. The questions below are original, written from the official objective title above, and each explanation cites the Cisco page it rests on.

Objective title verbatim from the official objectives. Cisco exam page ↗

A worked example

Shown solved, with the whole explanation open: this is what every question here carries.

1-2Network Fundamentals

A data center is drawn as a folded Clos fabric with servers at the bottom edge. Which devices in that drawing carry the spine role?

The switches servers connect into directlyThat is the leaf stage, the input and output layer of the fabric where servers land.
The middle stage above the server-facing tierCorrect · your answerCorrect. The stage between leaves, facing no servers at all, is the spine.
The pair of routers facing the wide areaBorder devices attach the fabric to the outside world and can sit at any tier of it.
Any switch holding a default route outwardHolding a default route is a routing policy choice and says nothing about a device's position.

Correct.

Checked against datatracker.ietf.org, August 2026

Concept

Naming in a folded topology follows position in the switching stages, not function or hardware. The stage that only ever faces other switches is distinct from the stage where hosts and external links attach.

Why B

In a folded Clos the input and output stage is where servers attach and is called leaf, while the stage sitting above it, connecting leaves to each other, is called spine. Every leaf reaches every spine, which is what makes the fabric uniform.

Source

"Spine" is the name given to the middle stage of the Clos topology (Tier 1) and "Leaf" is the name of input/output stage…

IETF RFC 7938, Use of BGP for Routing in Large-Scale Data Centers, section 3, checked August 2026
#topology#spine and leaf#data centre

Now you: objective 1.2 questions

No account needed. The explanation opens when you answer.

Sample question 1 of 3

1-2Network Fundamentals

A leaf switch in a Clos fabric has 4 uplink ports toward the spine and 16 downlink ports toward servers, all the same speed. What is the oversubscription of that leaf?

Sample question 2 of 3

1-2Network Fundamentals

An engineer proposes summarising server prefixes on the spine switches of a Clos fabric to shrink the routing tables. Why is that risky?

Sample question 3 of 3

1-2Network Fundamentals

A team wants to widen a layer 2 access design by adding a fifth and sixth uplink per switch, with spanning tree keeping the topology loop free. What limits that plan?

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Read the sources

These are the official pages the questions above cite. Reading them is studying the objective from the primary source, which is what the explanations point you toward anyway.

More objectives in Network Fundamentals