When is a collapsed-core architecture appropriate?

A collapsed-core architecture combines the core and distribution layers into a single device or set of devices. This design is appropriate for small networks with limited growth requirements because it reduces complexity and cost. While it simplifies the network, it also creates a single point of failure and limits scalability, making it unsuitable for large or rapidly expanding networks. VSS (Virtual Switching System) can be used with collapsed-core, but it's not a prerequisite or the sole reason for its appropriateness. Large networks with many remote sites require a more robust, hierarchical design. While access and distribution layers can be on the same device in a collapsed core, this is a characteristic of the architecture, not the primary reason for choosing it.