Content

| Summary

This module has defined scalability and provided examples of Cisco IOS features that enable successful network expansion. This module also explained the three layer design model. This conceptual model helps administrators configure routers to meet specific needs for a layer. Recall that scalable networks also have the following characteristics:

- Reliable and available
- Responsive
- Efficient
- Adaptable
- Accessible but secure

These concepts will apply in the entire CCNP 1 curriculum.