Ccna ® Certification Practice Tests Jon Buhagiar

Definition is not a term used with YAML; therefore, option A is

an invalid answer. Lists are keys with multiple values in the

form of a list. Keys are categories that contain a value in the key-

value pair.

8. A.  A YAML file will always begin with three dashes. This is how

you know you are working with a YAML file structure. Files that

start with a hashbang preprocessor are normally scripts, and the

hashbang describes to the operating system which command

interpreter to use. A file that has its content contained between

curly braces or square braces is normally a JSON file.

9. D.  Extensible Markup Language (XML) was adopted from

HyperText Markup Language (HTML) as a storage method for

systems to interchange data. YAML Ain’t Markup Language

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(YAML) is a white space structured file that is also used to store

data for the interchange of information. JavaScript Object

Notation (JSON) is another structured storage method for data

and was originally created for use with JavaScript and gained

popularity with other languages. Comma-separated values

(CSV) is a flat data storage method that is popular when lists of

information must be passed from system to system.

10. A.  YAML Ain’t Markup Language (YAML) is a white space

structured file that is also used to store data for the interchange

of information. JavaScript Object Notation (JSON) is structured

with curly and square brackets. Extensible Markup Language

(XML) was adopted from HyperText Markup Language

(HTML), which uses opening and closing tags. Comma-

separated values (CSV) is a flat data storage method that uses

commas to delimit the fields of information held on each line.

11. B.  The application programming interface (API) on the device

that is to be controlled through automation should be

researched. The API is a method for controlling devices with

programmability control; this includes the import and export of

information. The user interface layout is more accustomed to

users and manual configuration, since programs do not use the

user interface. The source code and data storage methods for the

device are not normally attainable and do not really get you

what you need to control the device.

12. B.  The Simple Network Management Protocol (SNMP) was

originally created to allow retrieval of information from network

devices and can be programmatically controlled, similar to an

application programming interface (API). The command-line

interface (CLI) is what the user will interface with; therefore, it

is considered a type of user interface (UI). Syslog is a method of

sending logging information to remote syslog servers. Secure

Shell (SSH) is a method for connectivity and not used as an API.

13. A.  The NETCONF protocol was created as a replacement for the

dated Simple Network Management Protocol (SNMP). Syslog is

a system of formatted messages for log file storage, either local

or remote, via the syslog protocol. Representational state

transfer (REST) is a set of constraints used for sending data to

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and from services. Secure Shell (SSH) is a method of connecting

to network devices through a console-based terminal emulator.

14. A.  The NETCONF protocol was created to interface with

network devices over the SSH protocol. Data transferred to and

from network devices with the NETCONF protocol must adhere

to the Yet Another Next Generation (YANG) data model.

Representational state transfer (REST) is a set of constraints

used for sending data to and from services. Simple Network

Management Protocol (SNMP) is a network management

protocol used to retrieve and send information to remote

network devices. YAML is a markup language used to store and

transfer data between applications.

15. B.  The RESTCONF protocol is used with a Hypertext Transfer

Protocol Secure (HTTPS) transport protocol. RESTCONF is the

successor of NETCONF, which uses SSH for device access.

RESTCONF now uses a common transport of HTTPS to send

and retrieve information from network devices. Simple Network

Management Protocol (SNMP) defines its own standard of

information set and retrieval and does not use HTTPS. Syslog is

a system of formatted messages for log file storage either local or

remote via the syslog protocol.

16. A.  A benefit of controller-based networking is increased

security. When ACLs and filters are applied, they are applied

informally to all nodes that are controlled by the controller.

There is not a reduction of problems that can be encountered in

a network with the introduction of controller-based networking.

Throughput will not increase magically because of the

introduction of controller-based networking. Complexity should

be reduced with the introduction of controller-based networking

because all of the configuration is centralized.

17. B.  Controller-based networking has a logically centralized

control plane to centrally control the data plane. The data plane

is not centralized because switching and routing of data must be

done very fast, usually with the use of application-specific

integrated circuits (ASICs). Controller-based networking comes

in many different forms, ranging from applications to hardware

appliances. Both controller-based network switching and

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autonomous network switching use ASICs, but controller-based

network switches do not centrally switch frames.

18. Software-Defined Wide Area Network (SD-WAN) is the term

commonly used to describe the combination of multiple sites to

act as one single network. Use cases of SD-WAN are disaster

recovery and remote office and branch office planning. software-

defined networking (SDN) is the term used to describe local area

network (LAN) controller-based networking. SD-LAN is not a

term commonly used, and therefore, option C is an invalid

answer. A virtual private network (VPN) will allow multiple sites

to act as one single network, but it is not centrally controlled

with controller-based networking.

19. C.  Controller-based networking, also known as software-

defined networking (SDN), is roughly 15 years old. Many see this

maturity as a disadvantage when comparing it to traditional

networking equipment that is much older in theory. Scalability,

security, and centralized provisioning are advantages to using

controller-based networking and far outweigh the disadvantage

of the youth of SDN.

20. C.  Quality of service (QoS) can be directly controlled with an

SDN controller. The SDN controller will push programming to

the SDN-enabled switch so that the switch can control the flow

of traffic. CPU and memory utilization can be reported upon,

and arguably programming can be pushed out to alleviate

central processing unit (CPU) and memory utilization, but CPU

and memory utilization is not directly controlled with an SDN

controller. The forwarding of traffic is a responsibility of the

data plane, which can be changed by the control plane.

However, the SDN controller does not forward packets

explicitly; that is the function of the switch.

21. B.  All software-defined network (SDN) switches are stateless

with respect to their configuration. The configuration is applied

from the central controller, and therefore, any configuration

contained on the switch does not matter if it is lost during a

reboot. Data is not centrally switched at the SDN controller; this

would make data transfer too slow and overburden the SDN

controller. The data flowing through the switch is not

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consequential to the SDN controller; some data flows can be

stateless, such as UDP, and some can be stateful, such as TCP.

22. A.  The Simple Network Management Protocol (SNMP) allows

for the central monitoring of switches and routers by using traps

and polling of network metrics. Syslog is a method of collecting

logs for passive analysis after an event has been brought to your

attention. Software-defined networking (SDN) allows for the

centralized control of switches and routers. The Cisco Discovery

Protocol (CDP) is used to discover Cisco devices on the

immediate network.

23. The Simple Network Management Protocol (SNMP) utilizes a

component called the network management station (NMS) to

collect all messages and poll metrics from all managed devices.

An SNMP trap is a message generated from an SNMP agent

installed on a host. An SNMP agent is a piece of software that

monitors the operating system and hardware and either reports

to the NMS or is polled by the NMS. A syslog server is a

centralized server that collects logs for passive analysis of

problems.

24. A.  The Simple Network Management Protocol (SNMP) along

with Telnet and Secure Shell (SSH) are used to configure

network devices with Cisco Prime. Control And Provisioning of

Wireless Access Points (CAPWAP) and Lightweight Access Point

Protocol (LWAPP) are used with wireless LAN controllers for

the configuration of wireless access points (WAPs). RESTCONF

is used with Cisco Digital Network Architecture (DNA) for

network device configuration.

25. B.  The Spine/Leaf architecture model has been adopted in

controller-based networks. The Leaf switch acts as the access

and distribution, and the Spine acts as the core or backbone for

the network. The three-tier network model and the collapsed

core network model are used with controller-based networking.

However, the concepts of the Cisco three-tier model are still

applicable, such as the access, distribution, and core concepts as

described above. A storage area network (SAN) fabric is not used

in a network or controller-based network, as it is applicable only

to storage area networks.

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26. D.  Leaf switches never connect to other Leaf switches; they only

connect to Spine switches. There can be many Spine switches

per network; they are considered the backbone of the network.

Although nothing stops you from connecting a host to a Spine

switch, Spine switches should only provide core/backbone

services.

27. A.  Traffic flow in a Spine/Leaf network flows from the host

connected to the Leaf to the Spine, eventually to the destination

Leaf and the awaiting host. Leaf switches are connected only to

the Spine; therefore, traffic cannot flow from the host to a Leaf

to another Leaf directly. Hosts should not be connected to Spine

switches, so traffic will not flow from the host to the Spine to a

Leaf and then a Spine switch.

28. D.  The Cisco Application Centric Infrastructure (ACI) software-

defined networking (SDN) solution is data center – focused to

deliver applications to end users. The Cisco Application Policy

Infrastructure Controller - Enterprise Module (APIC-EM) is a

legacy SDN solution that is not part of Cisco Digital Network

Architecture (DNA). OpenDaylight (ODL) is an open platform

used for SDN solutions; it is not provided or maintained by

Cisco. The Cisco Software-Defined Wide-Area Network (SD-

WAN) is a scalable SDN solution for networks that operate over

several data centers.

29. B.  Cisco Software Defined - Wide Area Network (SD-WAN) is a

solution that will allow remote office/branch office (ROBO)

personnel to access cloud-based applications directly. The Cisco

Application Policy Infrastructure Controller - Enterprise Module

(APIC-EM) is a legacy SDN solution that is not part of Cisco

Digital Network Architecture (DNA). Cisco Prime Infrastructure

is a legacy management tool for deployment of switches, routers,

and wireless. OpenDaylight (ODL) is an open platform used for

SDN solutions; it is not provided or maintained by Cisco.

30. B.  The campus networking model is a traditional networking

model that is deployed as either a three-tier model with a core,

distribution, and access layer or a collapsed core model. In the

collapsed core model, the core and distribution layers are the

same functional equipment. The Spine/Leaf, also known as the

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CLOS model, is commonly found in software-defined

networking (SDN).

31. C.  The software-defined network (SDN) controller replaces the

control plane on SDN devices. The SDN devices in the network

do not contain a control plane locally and instead are controlled

by the SDN controller. The SDN controller does not configure

the management plane of the network devices; it replaces the

management plane of the network devices. The SDN controller

does not monitor the data plane of traffic; it only controls the

traffic. The SDN controller does not complement the control

plane of the SDN device; it replaces the control plane of the SDN

device.

32. A.  Application Policy Infrastructure Controller - Enterprise

Module (APIC-EM) is a Cisco SDN controller. This package is

freely downloadable from the Cisco DevNet website as of the

writing of this book. It comes with several built-in apps, such as

a plug and play module and a path trace module. Many other

apps can be built on top of the APIC to extend functionality of

the controller. However, the product has been largely replaced

with Cisco DNA and is now licensed. OpenSDN is an open-

source SDN controller platform that utilized the open-source

OpenDaylight (ODL) protocol. OpenStack is another open-

source SDN controller aimed at data centers.

33. B.  The control plane refers to any mechanism that controls the

data plane. STP is used to control the data plane by removing

redundant links. The data plane is responsible for switching and

routing data. Any data that is destined for endpoints is switched

or routed on the data plane. The management plane is any

mechanism that helps in the management of a router or switch.