A "solid" design anticipates growth. This involves using modular hardware and a structured IP addressing scheme (IPv6 or CIDR) that allows for easy expansion without reconfiguring the entire system.
High availability is non-negotiable. Designers use dual-homing (connecting a switch to two upstream devices) and protocols like STP (Spanning Tree Protocol) or LACP (Link Aggregation Control Protocol) to ensure that if one cable or switch fails, the network stays live.
The "interchange." This layer implements policies, routing between VLANs (Virtual Local Area Networks), and security filtering. It bridges the high-speed core with the user-facing access layer.
