Network Fundamentals - End of Chapter Review Questions

Review Questions 1. What software allows you to define VMs and manage resource allocation and sharing among VMs on a host computer? a. Hypervisor b. NFV (Network Functions Virtualization) c. SDN (software-defined networking) d. Terminal emulation Answer: a. Hypervisor Explanation: A hypervisor creates and manages a VM and allocates hardware resources for the host and any of its guest VMs. NFV (Network Functions Virtualization) is the merging of physical and virtual network architecture. SDN (software-defined networking) is a centralized approach to networking that removes most of the decision-making power from network devices and instead handles that responsibility at a software level. Terminal emulation, also called remote virtual computing, allows a remote client to take over and command a host computer. 2. What virtual, logically defined device operates primarily at the data link layer to pass frames between nodes? a. Virtual firewall b. Virtual switch c. Virtual router d. Virtual load balancer Answer: b. Virtual switch Explanation: A vSwitch (virtual switch) or bridge is a logically defined device that operates at the data link layer to pass frames between nodes. NFV (Network Functions Virtualization) provides flexible, cost-saving options for many types of network devices, including virtual routers, virtual load balancers, and virtual firewalls. 3. Which device can manage traffic to multiple servers in a cluster so all servers equally share the traffic? a. Router b. Firewall c. Switch d. Load balancer Answer: d. Load balancer Explanation: A load balancer helps to evenly distribute traffic to each device in a server cluster so every device carries a portion of the load. A router uses logical addressing information to direct data between two or more networks and can help find the best path for traffic to get from one network to another. A firewall selectively filters or blocks traffic between networks. A switch logically subdivides a network into smaller, individual collision domains. 4. With which network connection type does the VM obtain IP addressing information from its host? a. Bridged mode b. Managed mode c. NAT mode d. Isolation mode Answer: c. NAT mode Explanation: In NAT (network address translation) mode, a VM obtains IP addressing information from its host rather than from a server or router on the physical network. Although a bridged vNIC communicates through the host’s adapter, it obtains its own IP address, default gateway, and subnet mask from a DHCP server on the physical LAN. Isolation mode is not a network connection type but is related to the way a VM gets access to host resources separately from other guests. Managed mode is not a network connection type. 5. Which type of switch connects all devices in a rack to the rest of the network? a. ToR switch b. Spine switch c. EoR switch d. Core switch Answer: a. ToR switch Explanation: A ToR (top of rack) switch connects all other devices in the rack to the rest of the network. EoR (end of row) switching places several leaf switches in a rack at the end of each row of racks. Core switches are highly efficient multilayer switches that support the network’s backbone traffic. Similarly, spine switches organize traffic and network segments using OSI layer 3 technologies. 6. Which cloud service model gives software developers access to multiple platforms for testing code? a. IaaS b. PaaS c. SaaS d. XaaS Answer: b. PaaS Explanation: PaaS (Platform as a Service) provides a platform on which to test or run code without having to manage the underlying server. IaaS (Infrastructure as a Service) provides virtual hardware services, including network infrastructure devices such as virtual servers and DNS services. SaaS (Software as a Service) consists of applications provided through an online user interface that are compatible with a variety of devices and operating systems. XaaS (Anything as a Service) emphasizes the ability of the cloud to provide any combination of functions depending on a client’s exact needs. 7. When shopping for a new router, what does the MTBF tell you? a. How long until that device fails b. How much it will cost to repair that device c. How long devices like this one will last on average until the next failure d. How long it will usually take to repair that device Answer: c. How long devices like this one will last on average until the next failure Explanation: MTBF (mean time between failures) indicates how long devices like this one will last before the next failure is expected to occur. No one can predict when a specific device will fail. The cost of repairs to a device can only be calculated once the problem is identified. MTTR (mean time to repair) calculates the average amount of time required to repair a device. 8. What information does the switchport port-security command use to restrict access to a switch’s interface? a. MAC address b. Port number c. IP address d. Broadcast address Answer: a. MAC address Explanation: The switchport port-security command restricts the number of MAC addresses per port and stores acceptable MAC addresses in a table that can be configured manually or dynamically. Firewalls filter traffic by port number or IP address. A broadcast address is used for managing broadcast traffic on a network. 9. Which of the following features of a network connection between a switch and server is not improved by link aggregation? a. Bandwidth b. Fault tolerance c. Speed d. Availability Answer: c. Speed Explanation: Link aggregation isn’t about speed of network traffic so much as bandwidth, fault tolerance, and resource availability. 10. Which cloud management technique executes a series of tasks in a workflow? a. Automation b. IaC c. SLA d. Orchestration Answer: d. Orchestration Explanation: Orchestration allows the automation of many individual tasks to work together in a robust workflow. Automation is a programmed, computer-generated response to a specific event. IaC (infrastructure as code) is the process of using text-based commands in a computer-readable configuration file to create and manage cloud resources. An SLA (service-level agreement) defines service standards, such as availability. 11. List two advantages to using virtualization on a network. Answer: Answers will include two of the following: • • • • Efficient use of resources Cost and energy savings Fault and threat isolation Simple backups, recovery, and replication 12. List available options for connecting to cloud resources. Answer: Organizations generally offer an array of options, including Internet, VPN (virtual private network), remote access connections (such as SSH and RDP), a leased line from an ISP, and a private or dedicated direct connection. 13. How does a vNIC get a MAC address without manual intervention? Answer: Upon creation, each vNIC is automatically assigned a MAC address. 14. What type of adapters are required on servers in an FCoE storage network? Answer: CNA (converged network adapter) 15. What are two use cases for a VIP (virtual IP address)? Answer: A single VIP (virtual IP address) can be used to represent a cluster of resources such as web servers. Alternatively, it might be used to assign a different IP address to multiple instances of the same service running on a single machine. 16. Which type of hypervisor is installed directly on top of the server’s firmware? Answer: Type 1 hypervisor 17. Only one exists on a network using STP. Answer: root bridge 18. What protocol is most often used to bond ports between a switch and a busy server? Answer: LACP (Link Aggregation Control Protocol) 19. How is licensing an important concern when using virtualization? Answer: Each virtualized device needs its own license in addition to a license for the hypervisor. 20. What kind of device can be used to configure and manage physical and virtual networking devices across the network? Answer: SDN controller or network controller