• The Collapsed Core Cisco Architecture, also called the Two-Tier Architecture, is a network design model commonly used for small to medium-sized enterprise networks.

    It simplifies the network structure by reducing the number of layers compared to the traditional Three-Tier Architecture.

    Here's what a typical Collapsed Core Cisco network looks like:

    Collapsed Core Cisco network architecture diagram showing core and access layers with switch connections

    Figure 1 – Collapsed Core: Core and Distribution merged into one layer

    Two Layers Instead of Three

    As you can see the Collapsed Core Architecture is made up of two layers:

    • Collapsed Core Layer

    • Access Layer

    To help you understand this architecture, let’s compare it to a traditional three-layer design:

    Comparison between Three-Tier Architecture and Collapsed Core Cisco design showing separate and merged network layers

    Figure 2 – Comparison between Three-Tier and Collapsed Core designs

    • On the left: Three-Tier Architecture separates the network into Core, Distribution, and Access layers.

    • On the right: Collapsed Core Cisco Architecture combines the Core and Distribution layers into a single layer.

    This new design reduces the number of layers, simplifying the network.

    When It Makes Sense

    The Collapsed Core Cisco Architecture offers several key advantages, but it also has some limitations that you need to consider:

    Advantages

    Limitations

    Simplified design: easier to deploy and manage.

    Limited scalability: not ideal for very large networks.

    Cost-effective: no need for expensive dedicated core switches.

    May cause bottlenecks: if too many access switches are added.

    In practice, this kind of design is perfect for:

    • Small and medium-sized businesses that don’t expect massive network growth.

    • Simple campus networks with a limited number of users and devices.

    • Organizations on a tighter budget that want solid performance without overspending.

    In short: if you want a network that’s easy to build, affordable and manageable, the Collapsed Core Cisco Architecture is a great fit.

    Now that you have the big picture, let’s dive into the details, starting with the Access Layer.

    Answer the question below

    In the Collapsed Core Architecture, which single layer replaces both the Core and Distribution layers?