11.5.3 Module Quiz – Network Design Answers
1. Which cost-effective physical network topology design is recommended when building a three-tier campus network that connects three buildings?
- dual ring
- extended star
Explanation: For efficiency, scalability, and cost-effectiveness, building an extended star topology from a centralized site to all other campus sites is recommended. A mesh topology is much more expensive, and bus and dual ring topologies are more difficult to troubleshoot and maintain.
2. How much traffic is a 48-port gigabit switch capable of switching when operating at full wire speed?
- 48 Gb/s, by providing full bandwidth to each port
- 1 Gb/s, because data can only be forwarded from one port at a time
- 44 Gb/s, due to overhead requirements
- 24 Gb/s, because this is the maximum forwarding rate on Cisco switches
Explanation: A switch operating at full wire speed is capable of switching the cumulative amount of each port on the switch. A 48-port gigabit switch could forward (48 x 1 Gb/s = 48 Gb/s) of data. Forwarding rates are determined based on the capabilities of each switch.
3. What is the term that is used for the area of a network that is affected when a device or network service experiences problems?
- collision domain
- user domain
- failure domain
- broadcast domain
Explanation: A failure domain is a portion of the network that is affected when a device or service fails or experiences problems.
4. Which type of router would an enterprise use to allow customers to access content anytime and anyplace, regardless of whether they are at home or work?
- branch routers
- network edge routers
- modular routers
- service provider routers
Explanation: Network edge routers provide customer interactivity, personalization, and mobility. Wherever customers can access an Internet connection, they can access their content. Branch routers provide simple network configuration and management while maintaining highly available networks. Modular routers are used to provide greater flexibility in which interfaces are used during network design and installation. Service provider routers provide end-to-end scalable solutions. Customers do not remotely access or connect directly to a service provider router.
5. Which design feature will limit the size of a failure domain in an enterprise network?
- the purchase of enterprise equipment that is designed for large traffic volume
- the installation of redundant power supplies
- the use of a collapsed core design
- the use of the building switch block approach
Explanation: In order to best limit the of a failure domain, routers or multilayer switches can be deployed in pairs. The failure of a single device should not cause the network to go down. Installing redundant power supplies may protect a single device from a power failure, but if that device suffers from another type of problem, a redundant device would have been a better solution. Purchasing enterprise equipment that handles large flows of traffic will not provide extra reliability in times of an outage. If a collapsed core design is used, the core and distribution are collapsed into a single device, increasing the chance of a devastating outage.
6. What is a function of the distribution layer?
- fault isolation
- network access to the user
- high-speed backbone connectivity
- interconnection of large-scale networks in wiring closets
Explanation: The distribution layer interacts between the access layer and the core by aggregating access layer connections in wiring closets, providing intelligent routing and switching, and applying access policies to access the rest of the network. Fault isolation and high-speed backbone connectivity are the primary functions of the core layer. The main function of the access layer is to provide network access to the user.
7. What is the function of PoE pass-through?
- allows switches, phones, and wireless access points to receive power over existing Ethernet cables from an upstream switch
- allows a multilayer switch to forward IP packets at a rate close to that of Layer 2 switching by bypassing the CPU
- allows multiple physical switch ports to be aggregated together and act as a single logical to increase bandwidth on trunk links
- allows a switch to disable redundant Layer 2 paths in the topology to prevent Layer 2 loops
Explanation: PoE or Power over Ethernet allows devices such as wireless access-points and IP phones to receive power from PoE enabled switch ports. PoE pass-through allows a switch to receive power from an upstream switch and pass it through to PoE devices.
8. Which function is supplied by the access layer in a three-layer network design?
- application of policies
- network access
- high-speed connectivity
- backbone connectivity
Explanation: The main purpose of devices in the access layer is to supply network access to end users. Distribution layer devices provide services such as routing and policy functions. The core layer provides high-speed backbone connectivity.
9. Which action should be taken when planning for redundancy on a hierarchical network design?
- Add alternate physical paths for data to traverse the network.
- Purchase backup equipment for every network device at the distribution layer.
- Immediately replace a nonfunctioning module, service ,or device on a network.
- Implement STP PortFast between the switches on the network.
Explanation: One method of implementing redundancy is path redundancy, which means installing alternate physical paths for data to traverse the network. Redundant links in a switched network support high availability and can be used for load balancing, thus reducing congestion on the network.
10. What is a collapsed core in a network design?
- a combination of the functionality of the access, distribution, and core layers
- a combination of the functionality of the access and distribution layers
- a combination of the functionality of the distribution and core layers
- a combination of the functionality of the access and core layers
Explanation: A collapsed core design is appropriate for a small, single building business. This type of design uses two layers (the collapsed core and distribution layers consolidated into one layer and the access layer). Larger businesses use the traditional three-tier switch design model.
11. What is the name of the layer in the Cisco borderless switched network design that is considered to be the backbone used for high-speed connectivity and fault isolation?
- data link
- network access
Explanation: The three layers of the Cisco borderless switch network design are access, distribution, and core. The access layer switches are the ones used to connect end devices to the network. The distribution layer switches accept connections from access layer switches and provides switching, routing, and access policy functions. The core layer is called the backbone and core switches commonly have high-speed redundant connections.
12. Which technology is required when switched networks are designed to include redundant links?
- Spanning Tree Protocol
- virtual LANs
- virtual private networks
- link aggregation
Explanation: Spanning Tree Protocol (STP) is required when switched networks include redundant Layer 2 links. VLANs, VPNs, and link aggregation are not related to link redundancy in network design.
13. Which feature could be used in a network design to increase the bandwidth by combining multiple physical links into a single logical link?
- trunk ports
Explanation: VLANs create several groups of users which use a single physical link. Trunk ports are single physical links. Subinterfaces allow one physical link to be used to create several logical links. EtherChannel provides the ability to combine multiple physical links into a single logical link.
14. Which statement describes a characteristic of Cisco Catalyst 2960 switches?
- New Cisco Catalyst 2960-C switches support PoE pass-through.
- They are best used as distribution layer switches.
- They do not support an active switched virtual interface (SVI) with IOS versions prior to 15.x.
- They are modular switches.
Explanation: Cisco Catalyst 2960 switches support one active switched virtual interface (SVI) with IOS versions prior to 15.x. They are commonly used as access layer switches and they are fixed configuration switches.
15. Which network design solution will best extend access layer connectivity to host devices?
- implementing wireless connectivity
- implementing redundancy
- implementing EtherChannel
- implementing routing protocols
Explanation: EtherChannel allows more data to be moved at the access layer, but does not provide network expansion. Redundancy is used to provide failover solutions but does not focus on network expansion. Routing protocols are not used to provide network expansion at the access layer. Wireless connectivity provides network access to a large number of users at the access layer.
16. What is a basic function of the Cisco Borderless Networks architecture distribution layer?
- Acting as a backbone
- Aggregating all the campus blocks
- Aggregating Layer 2 and Layer 3 routing boundaries
- Providing access to end-user devices
Explanation: One of the basic functions of the distribution layer of the Cisco Borderless Networks architecture is to perform routing between different VLANs. Acting as a backbone and aggregating campus blocks are functions of the core layer. Providing access to end-user devices is a function of the access layer.
17. Which two previously independent technologies should a network administrator attempt to combine after choosing to upgrade to a converged network infrastructure? (Choose two.)
- Electrical system
- Mobile cell phone traffic
- Scanners and printers
- User data traffic
- VoIP phone traffic
Explanation: A converged network provides a single infrastructure that combines voice, video, and data. Analog phones, user data, and point-to-point video traffic are all contained within the single network infrastructure of a converged network.
18. How is a two-tier LAN network design implemented?
- The access, distribution, and core layers are collapsed into one tier to separate the backbone layer.
- The access and core layers are collapsed into one tier, and the distribution layer is on a separate tier.
- The access and distribution layers are collapsed into one tier, and the core layer is on a separate tier.
- The distribution and core layers are collapsed into one tier, and the access layer is on a separate tier.
Explanation: Maintaining three separate network tiers is not always required or cost-efficient. All network designs require an access layer, but a two-tier design can collapse the distribution and core layers into one layer to serve the needs of a small location with few users.
19. A local law firm is redesigning the company network so that all 20 employees can be connected to a LAN and to the internet. The law firm would prefer a low-cost and easy solution for the project. What type of switch should be selected?
- fixed configuration
- modular configuration
- stackable configuration
- data center switch
- service provider switch
Explanation: A fixed-configuration switch would meet all the requirements of the law firm in this example.
20. What is one function of a Layer 2 switch?
- determining which interface is used to forward a frame, based on the destination MAC address
- duplicating the electrical signal of each frame to every port
- forwarding data based on logical addressing
- learning the port assigned to a host by examining the destination MAC address
Explanation: A switch builds a table of MAC addresses and associated port numbers by examining the source MAC addresses found in inbound frames. To forward a frame onward, the switch examines the destination MAC address, looks in the MAC address for a port number associated with that destination MAC address, and sends it to the specific port. If the destination MAC address is not in the table, the switch forwards the frame out all ports except the inbound port that originated the frame.
21. Which network device can be used to eliminate collisions on an Ethernet network?
- Wireless access point
Explanation: A switch provides microsegmentation so that no other devices compete for the same Ethernet network bandwidth.
22. Which type of address does a switch use to build the MAC address table?
- Destination IP address
- Destination MAC address
- Source IP address
- Source MAC address
Explanation: When a switch receives a frame with a source MAC address that is not in the MAC address table, the switch adds that MAC address to the table and maps that address to a specific port. Switches do not use IP addressing in the MAC address table.
23. What are two reasons a network administrator would segment a network with a Layer 2 switch? (Choose two.)
- To create fewer collision domains
- To create more broadcast domains
- To eliminate virtual circuits
- To enhance user bandwidth
- To isolate ARP request messages from the rest of the network
- To isolate traffic between segments
Explanation: A switch has the ability to create temporary point-to-point connections between the directly attached transmitting and receiving network devices. The two devices have full-bandwidth, full-duplex connectivity during the transmission. Segmentation adds collision domains to reduce collisions.
24. Which statement describes the microsegmentation feature of a LAN switch?
- All ports inside the switch form one collision domain.
- Each port forms a collision domain.
- Frame collisions are forwarded.
- The switch does not forward broadcast frames.
Explanation: When a LAN switch with the microsegmentation feature is used, each port represents a segment, which in turns forms a collision domain. If each port is connected with an end-user device, there will be no collisions. However, if multiple end devices are connected to a hub and the hub is connected to a port on the switch, some collisions will occur in that particular segment-but not beyond it.
25. A ____________________ network is one that uses the same infrastructure to carry voice, data, and video signals.
26. In the Cisco enterprise architecture, which two functional parts of the network are combined to form a collapsed core design? (Choose two.)
- Access layer
- Core layer
- Distribution layer
- Enterprise edge
- Provider edge
Explanation: The Cisco enterprise architecture consists of a hierarchical design. The network is divided into three functional layers: core, distribution, and access. In smaller networks, this three-layer division of functional layers is collapsed into two layers, with the core and distribution layers combined to form a collapsed core.
27. What are two benefits of extending access layer connectivity to users through a wireless medium? (Choose two.)
- Decreased number of critical points of failure
- Increased bandwidth availability
- Increased flexibility
- Increased network management options
- Reduced costs
Explanation: Providing wireless connectivity offers many advantages, such as increased flexibility, reduced costs, and the ability to grow and adapt to changing network and business requirements.
28. As the network administrator, you have been asked to implement EtherChannel on the corporate network. What does this configuration involve?
- Grouping multiple physical ports to increase bandwidth between two switches
- Grouping two devices to share a virtual IP address
- Providing redundant devices to allow traffic to flow in the event of device failure
- Providing redundant links that dynamically block or forward traffic
Explanation: Link aggregation allows an administrator to increase the amount of bandwidth between devices by creating one logical link by grouping several physical links together. EtherChannel is a form of link aggregation used in switched networks.
29. Which statement describes Cisco Meraki switches?
- They are campus LAN switches that perform the same functions as Cisco 2960 switches.
- They are cloud-managed access switches that enable virtual stacking of switches.
- They are service provider switches that aggregate traffic at the edge of the network.
- They promote infrastructure scalability, operational continuity, and transport flexibility.
Explanation: Cisco Meraki cloud-managed access switches enable virtual stacking of switches. They monitor and configure thousands of switch ports over the web, without the intervention of onsite IT staff.
30. What term is used to describe the thickness or height of a switch?
- Domain size
- Module size
- Port density
- Rack unit
Explanation: The thickness of a switch determines how much space on the rack it will take up and is measured in rack units.
31. What are two functions of a router? (Choose two.)
- It connects multiple IP networks.
- It controls the flow of data via the use of Layer 2 addresses.
- It determines the best path for sending packets.
- It increases the size of the broadcast domain.
- It manages the VLAN database.
Explanation: Routers play a critical role in networking by determining the best path for sending packets. They connect multiple IP networks by connecting homes and businesses to the internet. They are also used to interconnect multiple sites within an enterprise network, providing redundant paths to destinations. Routers can also act as translators between different media types and protocols.