CCNA 2 v5 Chapter 1: Check Your Understanding Questions Answers

CCNA 2 Routing and Switching Essentials v5 Chapter 1: Introduction to Switched Networks – Check Your Understanding Questions Answers

1. Which three options correctly associate a layer of the hierarchical design model with the function of that layer? (Choose three.)

Core – end device connectivity
Distribution – aggregation and traffic control
Access – end device connectivity
Distribution – high speed backbone
Access – aggregation of traffic
Core – high speed backbone

Explanation: Access Layer:
The access layer represents the network edge, where traffic enters or exits the campus network. Traditionally, the primary function of an access layer switch is to provide network access to the user. Access layer switches connect to distribution layer switches, which implement network foundation technologies such as routing, quality of service, and security.

Distribution Layer:
The distribution layer interfaces between the access layer and the core layer to provide many important functions, including:
– Aggregating large-scale wiring closet networks
– Aggregating Layer 2 broadcast domains and Layer 3 routing boundaries
– Providing intelligent switching, routing, and network access policy functions to access the rest of the network
– Providing high availability through redundant distribution layer switches to the end-user and equal cost paths to the core
– Providing differentiated services to various classes of service applications at the edge of the network

Core Layer:
The core layer is the network backbone. It connects several layers of the campus network. The core layer serves as the aggregator for all of the other campus blocks and ties the campus together with the rest of the network. The primary purpose of the core layer is to provide fault isolation and high-speed backbone connectivity.

2. Which hierarchical network design goal is to provide a way for the network to always be accessible?

hierarchical
modularity
resiliency
flexibility

Explanation: Resiliency: Satisfies user expectations for keeping the network always on

3. Which two layers of the hierarchical network design model are commonly combined into a single layer in a small-to-medium sized network architecture? (Choose two.)

access
data link
network
distribution
application
core

Explanation: In some cases, because of a lack of physical or network scalability restrictions, maintaining a separate distribution and core layer is not required. In smaller campus locations where there are fewer users accessing the network or in campus sites consisting of a single building, separate core and distribution layers may not be needed.

4. What is convergence as it relates to network design?

Implementation of an access-distribution-core layer design model for all sites in a corporation
A centralized point in the network design where all traffic aggregates before transmission to the destination
The combining of voice and video with traditional network traffic
Designing a network in such a way that each tier has a specific function and upgrade path

Explanation: The convergence of services onto the network has resulted in an evolution in networks from a traditional data transport role, to a super-highway for data, voice, and video communication.

5. What are three benefits of a converged network? (Choose three.)

Voice and data support staff are combined.
Network design is simplified.
Network configuration is simplified.
Voice, video, and data traffic use one physical network.
Maintenance is simpler than hierarchical networks.
Network moves, adds, and changes are simplified.

Explanation: A converged network requires more complex configuration, maintenance, and hierarchical design than a traditional data network.

6. Which two terms are correctly defined? (Choose two.)

Internal switching rate – processing capability of a switch that quantifies how much data it can process per second
Port density – capability to use multiple switch ports concurrently for higher throughput data communication
Rack unit – number of ports that can fit in a specific switch
Cut-through switching – the transmission of a frame after the destination MAC address has been examined and processed
Modular configuration switch – only support features or options that ship with the device

Explanation: Port density is the number of ports available on a single switch. Rack unit is used to describe the switch height and is used in network rack space planning. A modular configuration switch allows great flexibility in configuration through the use of line cards in the various available chassis sizes.

7. A switch that uses MAC addresses to forward frames operates at which layer of the OSI model?

Layer 1
Layer 2
Layer 3
Layer 4

Explanation: MAC addresses are associated with Ethernet frames and are also known as a Layer 2 address.

8. A switch has just been powered on. PC1 connects to port 1; PC2 connects to port 2. If PC1 sends data to PC2, how will the switch process the frame?

The switch forwards the frame based on the MAC address of PC2.
The switch adds the MAC address of PC1 (that is received on the ingress port) to the switch MAC address table.
The switch forwards the frame to all switch ports including ports 1 and 2.
The switch adds the IP address of PC2 (that is sent through the egress port) to the switch MAC address table.

Explanation: When a switch is first powered on, it has no entries in the MAC address table. A switch adds to the MAC address table by examining the Layer 2 header source MAC address. If the MAC address is not already in the switch MAC address table, the switch adds it. The switch forwards the frame based on the destination MAC address found in the Layer 2 header. If the destination MAC address is not in the MAC address table, the switch forwards the data to all ports that have devices attached except for the ingress port through which the switch received the frame.

9. What function is most likely to be provided by a Cisco access layer switch?

PoE
Routing
Link aggregation
Fault isolation

Explanation: Access layer switches commonly provide Power over Ethernet (PoE) to end devices such as access points and IP phones.

10. Use the abbreviated MAC addresses in the MAC address table to determine the correct answer. A PC connected to port Gi0/3 sends data to a PC connected to port Gi0/5. When the switch receives the data, what will the switch do to process the frame?

Port      MAC address
Gi0/3     AA
Gi0/7     AB

Add the destination MAC address to the switch MAC address table.
Forward the data out all ports except for port Gi0/3.
Forward the data to port Gi0/3.
Forward the data out all ports.
Add both the source and destination MAC addresses to the switch MAC address table.

Explanation: After the switch has recorded the source address information, the switch examines the destination MAC address. If the destination address is not in the MAC table or if it’s a broadcast MAC address, as indicated by all Fs, the switch floods the frame to all ports, except the ingress port (Gi0/3).

11. Use the abbreviated MAC addresses in the MAC address table to determine the correct answer. A PC connected to port Gi0/4 sends data to a PC connected to port Gi0/3. When the switch receives the data, what will the switch do first to process the frame?

Port      MAC address
Gi0/3     AA
Gi0/7     AB

Add the source MAC address to the switch MAC address table.
Forward the data out all ports except for port 4.
Forward the data to port 5.
Forward the data out all ports.
Add both the source and destination MAC addresses to the switch MAC address table.
Add the destination MAC address to the switch MAC address table.

Explanation: The switch examines the source MAC address and compares it to the MAC address table. If the address is not in the MAC address table, it associates the source MAC address of PC with the ingress port (Port Gi0/4) in the MAC address table.