Class Activity – Network by Design - Answers

Certification Answers Class Activity – Network by Design (Instructor Version)

Instructor Note: Red font color or gray highlights indicate text that appears in the instructor copy only.


Explain the need to design a hierarchical network that is scalable.

Instructor Note: This activity is can be completed by individuals or groups of two students. It can then be shared with another individual, group, class, or the instructor.


Your employer is opening a new, branch office.

You have been reassigned to the site as the network administrator where your job will be to design and maintain the new branch network.

The network administrators at the other branches used the Cisco, three-layer, hierarchical approach when designing their networks. You decide to use the same approach.

To get an idea of what using the hierarchical model can do to enhance the design process, you research the topic.


  • Internet access
  • Word processing software


Step 1: Use the Internet to find information and take notes about the Cisco, three-layered hierarchical model. The site should include information about the:

a. Access layer

b. Distribution layer

c. Core layer

Step 2: In your research, make sure to include:

a. A simple definition of each hierarchical layer

b. Three concise facts about each layer

c. Network device capabilities needed at each layer

d. A detailed graphic that shows a full, three-layer hierarchical model design

Step 3: Create a simple table to organize and share your research with another student, group, the class, or instructor.

Suggested Activity Example Solution: (information based on The Cisco Three-Layered Hierarchical Model and LAN Design)

Access Layer
Definition This hierarchical layer connects local clients to the network. It is sometimes called the desktop layer.
Facts At this level:
– Network equipment works with the distribution and core layers to send and
receive transmissions from clients and users.
– Collision domains are created using switches.
– Switches can be configured to filter MAC addresses and share bandwidth.
Network Device Features – Port security
– VLANs functionality
– Fast Ethernet/Gigabit Ethernet transmissions
– Power over Ethernet (PoE)
– Link aggregation
– Quality of service (QoS)
Distribution Layer
Definition This hierarchical layer provides policy-based, decision-making network connectivity to the access layer below it and the core layer above it.
Facts At this level:
– Firewalls and access lists can be placed.
– Link aggregation can occur.
– Broadcast and multicast domain boundaries are created.
Network Device
– Layer 3 support
– High forwarding rate
– Gigabit Ethernet/10 Gigabit Ethernet
– Redundant components
– Security policies/access control lists
– Link aggregation
– Quality of service (QoS)
Core Layer
Definition This hierarchical layer is the backbone of the network. It includes high-powered routers and switches that use high-speed cabling, such as fiber optics. The main function of this layer is reliable delivery of network packets.
Facts At this level:
– All other layers of the hierarchical design model are supported.
– Load balancing is desired as an integral service.
– Efficient, fast, reliable data paths ensure fast network transmissions.
Network Device Features – Layer 3 support
– Very high forwarding rate
– Gigabit Ethernet/10 Gigabit Ethernet
– Redundant components
– Link aggregation
– Quality of service (QoS)
Three-Layer Hierarchical Design Graphic

Identify elements of the model that map to IT-related content:

  • Network design
  • Cisco three-layer hierarchical model
  • Access layer
  • Distribution layer
  • Core layer