Network design plans architecture, technologies, capacity, and connectivity around operational needs. Budget, scale, and specific requirements shape the appropriate solution, so few designs are universally correct. Understanding architectural principles helps configure and troubleshoot networks. section 15.0 section 15.5
Common architectural choices include:
- Star or hub-and-spoke: devices connect through one central device; star is common in LANs and hub-and-spoke in WANs. section 15.5
- Full mesh: every device connects directly to every other device; partial mesh connects only selected devices. Hybrid networks combine multiple patterns. section 15.5
- Campus LANs commonly use modular access, distribution, and core layers. Two-tier designs omit the core and are called collapsed-core architectures. section 15.5
The access layer connects end hosts and commonly implements QoS, security services, and PoE. The distribution layer aggregates access connections, borders Layer 2 and Layer 3, and can provide WAN or Internet connectivity and FHRP redundancy. section 15.5
