Cisco CCNA mock exam questions sample test – Question 22

.Which of the following should be a characteristic of the core layer in the Cisco three-layer hierarchical model?

A. redundant components
B. emphasis on high speed
C. PoE
D. QoS

Correct Answer: B

Explanation:
The core layer of the Cisco three-layer hierarchical network design model places an emphasis on high speed. Items such as access control lists (ACLs) and Quality of Service (QoS)
should NOT be implemented on this level, as those types of service will slow the high-speed switching process desired at this level.
The three layers of the hierarchical design model are the access layer, the distribution layer, and the core (backbone) layer. The core layer connects to every building block in the
modular network, so it must emphasize speed and resilience.
Quality of service and ACLs are implemented on the distribution layer. Layer 3 support is required at this level.
Redundant hardware components and Power over Ethernet (PoE) are characteristics of the access layer. This is the layer where user devices are connected to the network. Layer 2
Port security is also implemented at this layer.
Objective:
Network Fundamentals
Sub-Objective:
Compare and contrast collapsed core and three-tier architectures
References:
Cisco >Home > Solutions > Enterprise > Programs for Enterprise > Design Zone > Design Zone for Campus > Design Guides > Campus Network for High Availability Design Guide >
Hierarchical Network Design Model