Network

Question 1

is two or more computer systems that are linked by a transmission medium and share one or more protocols that enable them to exchange data.

Answer 1

A network

Question 2

are devices that send, receive, and forward data

Answer 2

The nodes

Question 3

are the communications pathways between them

Answer 3

the links

Question 4

perform a forwarding function

Answer 4

Intermediate nodes

Question 5

are those that send and receive data traffic

Answer 5

end system nodes

Question 6

also referred to as hosts

Answer 6

End systems

Question 7

makes network applications and resources available to other hosts

Answer 7

A server

Question 8

consumes the services provided by servers

Answer 8

A client

Question 9

is one where some nodes, such as PCs, laptops, and smartphones, act mostly as clients. The servers are more powerful computers. Application services and resources are centrally provisioned, managed, and secured

Answer 9

A client-server network

Question 10

is one where each host acts as both client and server. This is a decentralized model where provision, management, and security of services and data are distributed around the network. also be referred to as a workgroup

Answer 10

A peer-to-peer network; P2P

Question 11

File sharing networks where data is distributed around the clients that use the network. Apart from consuming bandwidth and disk space, ____ sites are associated with hosting malware and illegal material.

Answer 11

P2P

Question 12

Business and enterprise networks are typically

Answer 12

client-server

Question 13

residential networks are more often ________

Answer 13

peer-to-peer

Question 14

is a computer with an operating system and software designed to perform a particular network role. Examples of these roles include the switches, routers, and wireless access points that forward data, the firewalls and intrusion detection systems that enforce security rules, and the load balancers and proxies that improve network performance. Can be deployed as physical hardware or virtual

Answer 14

an appliance

Question 15

The nodes and links of networking infrastructure are deployed to run services. Services are shared ______that allow the network to do useful work, such as sharing files or allowing employees to send email.

Answer 15

applications

Question 16

Networks can be configured with additional properties to perform different ____. For example, the security properties of a virtual private network allow devices to join a local network from across the Internet. As another example, quality of service _____ allows optimization of a network to suit a particularly time-sensitive application, such as voice or video.

Answer 16

functions

Question 17

refers primarily to its size and scope. The size of a network can be measured as the number of nodes, while the scope refers to the area over which nodes sharing the same network address are distributed.

Answer 17

A network type

Question 18

is confined to a single geographical location. In a ___, all nodes and segments are directly connected with cables or short-range wireless technologies. Most of the network infrastructure in a ___ would be directly owned and managed by a single organization.

Answer 18

A local area network (LAN)

Question 19

With an Internet router and a few computers, plus mobile devices, gaming consoles, and printers.

Answer 19

example of LAN; Home/residential network

Question 20

A business-oriented network possibly using a centralized server in addition to client devices and printers, but often still using a single Internet router/switch/access point to provide connectivity.

Answer 20

example of LAN; Small office/home office (SOHO) network

Question 21

A network supporting dozens of users. Such networks would use structured cabling and multiple switches and routers to provide connectivity.

Answer 21

example of LAN; Small and medium-sized enterprise (SME) Network

Question 22

A larger network with hundreds or thousands of servers and clients. Such networks would require multiple enterprise-class switch and router appliances to maintain performance levels.

Answer 22

example of LAN; Enterprise LAN

Question 23

A network that hosts only servers and storage, not end user client devices.

Answer 23

example of LAN; Datacenter

Question 24

is a network of networks, connected by long-distance links. connect a main office site with multiple branch office sites, possibly in different countries. could link two or more large LANs or could be used for remote workers connecting to an enterprise network via a public network such as the Internet.

Answer 24

A wide area network (WAN)

Question 25

describes the physical or logical structure of the network in terms of nodes and links. Network specification that determines the network's overall layout, signaling, and dataflow patterns.

Answer 25

the topology

Question 26

describes the placement of nodes and how they are connected by the transmission media. For example, in one network, nodes might be directly connected via a single cable; in another network, each node might connect to a switching appliance via separate cables.

Answer 26

A network's physical topology

Question 27

describes the flow of data through the network. For example, given the different physical network topologies described previously, if in each case the nodes can send messages to one another, the ____ is the same. The different physical implementations—directly connected via a cable versus connected to the same switch—achieve the same _______.

Answer 27

logical topology

Question 28

a single link is established between two nodes. Because only two devices share the connection, they are guaranteed a level of bandwidth.

Answer 28

point-to-point link

Question 29

point to point; when the network media is ____, a node cannot transmit and receive at the same time

Answer 29

half-duplex

Question 30

point to point; when the network is _____, nodes can transmit and receive simultaneously

Answer 30

full-duplex

Question 31

each endpoint node is connected to a central forwarding appliance, such as a switch or router. The central node mediates communications between the endpoints. most widely used physical topology.

Answer 31

In a star topology

Question 32

has the same physical layout as a star topology but is primarily used in a different context. is more commonly applied to wide area networks (WANs) with remote sites. Network connectivity between multiple virtual private clouds where one virtual private cloud (VPC) acts as a hub and the other VPCs are peered with it but not with each other.

Answer 32

the hub-and-spoke topology

Question 33

is commonly used in WANs, especially public networks such as the Internet. A full _________ requires that each device has a point to point link with every other device on the network. This approach is normally impractical, however. expressed as n(n–1)/2, where n is the number of nodes

Answer 33

A mesh topology

Question 34

consists of a trunk cable with nodes either inserted directly into the trunk or tapped into the trunk using offshoot cables called drop cables. A device called a terminator is placed at both ends of the trunk cable. Their purpose is to absorb signals, preventing them from reflecting repeatedly back and forth on the cable. The major downside of using a ______ is that a broken cable anywhere on the ____ breaks the termination and prevents communications between all devices on the network.

Answer 34

A bus topology

Question 35

connects neighboring nodes until they form a ring or a circle. Signals travel in one direction around the ring, with each device on the network acting as a repeater to send the signal to the next device. A node malfunction or cable break can prevent signals from reaching nodes beyond the malfunction. This interconnectedness can cause difficulties with problem isolation, requiring the troubleshooter to check several physical locations along the ring.

Answer 35

A ring topology

Question 36

Assigns network and hardware components and functions at seven discrete layers: Physical, Data Link, Network, Transport, Session, Presentation, and Application.

Answer 36

Open Systems Interconnection (OSI) reference model

Question 37

OSI Model

Answer 37

7 - Application 6 - Presentation 5 - Session 4 - Transport 3 - Network 2 - Data Link 1 - Physical

Question 38

is a set of rules for exchanging data in a structured format. A ______ has two principal functions: Addressing and Encapsulation

Answer 38

network protocol

Question 39

Describing where data messages should go. At each OSI model layer, there are different mechanisms for identifying nodes and rules for how they can send and receive messages. Unique identifier for a network node, such as a MAC address, IPv4 address, or IPv6 address.

Answer 39

Addressing

Question 40

Describing how data messages should be packaged for transmission. Encapsulation is like an envelope for a letter, with the distinction that each layer requires its own envelope. At each layer, the protocol adds fields in a header to whatever payload data it receives from an application or other protocol. A method by which protocols build data packets by adding headers and trailers to existing data.

Answer 40

Encapsulation

Question 41

Network packet encapsulating a data payload from an upper layer protocol with header fields used at the current layer. At each level (except the Physical layer), the sending node adds a header to the data payload, forming a “chunk” of data called a

Answer 41

protocol data unit (PDU)

Question 42

At each layer, for two nodes to communicate they must be running the same protocol. The protocol running at each layer communicates with its peer layer on the other node. This communication between nodes at the same layer is described as a ____

Answer 42

same layer interaction.

Question 43

To transmit or receive a communication, on each node, each layer provides services for the layer above and uses the services of the layer below. This is referred to as _____

Answer 43

adjacent layer interaction.

Question 44

is responsible for the transmission and receipt of the signals that represent bits of data. Transmission media can be classified as cabled or wireless

Answer 44

The Physical layer (PHY) of the OSI model is defined as layer 1

Question 45

A physical signal conductor is provided between two nodes. Examples include copper or fiber optic . _____ media can also be described as _______.

Answer 45

Cabled; bounded media

Question 46

Uses free space between nodes, such as microwave radio. _____ media can also be described as ____

Answer 46

Wireless; unbounded media.

Question 47

The Physical layer specifies the following:

Answer 47

Physical topology, physical interface, and signaling

Question 48

The layout of nodes and links as established by the transmission media. An area of a larger network is called a segment. A network is typically divided into segments to cope with the physical restrictions of the network media used, to improve performance, or to improve security. At the Physical layer, a segment is where all the nodes share access to the same media.

Answer 48

Physical topology

Question 49

Mechanical specifications for the network medium. For cabled media, this means the construction of the cable, the interface/connector form factor, and the number and functions of the pins in a connector. For wireless media, it means radio transceiver and antenna specifications.

Answer 49

Physical interface

Question 50

The process of transmitting and receiving encoded data over the network medium. A modulation scheme describes how electrical, light, or radio signals represent bits. Timing and synchronization schemes ensure senders and receivers can identify groups of signals as a chunk or frame of data.

Answer 50

Signaling

Question 51

Devices that operate at the Physical layer include the following:

Answer 51

Transceiver, Repeater, Hub, and Media converter

Question 52

The part of a network interface that sends and receives signals over the network media. Component in a network interface that converts data to and from the media signaling type. Modular _______ are designed to plug into switches and routers.

Answer 52

transceiver

Question 53

A device that amplifies an electronic signal to extend the maximum allowable distance for a media type. Layer 1 device that regenerates and retransmits signals to overcome media distance limitations.

Answer 53

Repeater

Question 54

A multiport repeater, deployed as the central point of connection for nodes. Layer 1 (Physical) network device used to implement a star network topology on legacy Ethernet networks, working as a multiport repeater.

Answer 54

Hub

Question 55

A device that converts one media signaling type to another.

Answer 55

Media converter

Question 56

It is responsible for transferring data between nodes on the same logical segment. a segment is one where all nodes can send traffic to one another using hardware addresses, regardless of whether they share access to the same media.

Answer 56

Layer 2 is referred to as the Data Link layer.

Question 57

A layer 2 segment might include multiple physical segments. This is referred to as a _____

Answer 57

logical topology.

Question 58

also performs an encapsulation function. It organizes the stream of bits arriving from the Physical layer into structured units called frames.

Answer 58

The Data Link layer

Question 59

Common term for the protocol data unit for layer 2. Each ___ contains a Network layer packet as its payload. The Data Link layer adds control information to the payload in the form of header fields. These fields include source and destination hardware addresses, plus a basic error check to test if the ___ was received intact.

Answer 59

frames

Question 60

Devices that operate at the Data Link layer include the following:

Answer 60

Network adapter or NIC, Bridge, Switch, and Wireless access point

Question 61

joins an end system host to network media (cabling or wireless) and enables it to communicate over the network by assembling and disassembling frames.

Answer 61

Network adapter or network interface card (NIC)

Question 62

is a type of intermediate system that joins physical network segments while minimizing the performance reduction of having more nodes on the same network; has multiple ports, each of which functions as a network interface.

Answer 62

Bridge

Question 63

An advanced type of bridge with many ports. A switch creates links between large numbers of nodes more efficiently. Intermediate system used to establish contention-free network segments at OSI layer 2 (Data Link). An unmanaged _____ does not support any sort of configuration.

Answer 63

Switch

Question 64

allows nodes with wireless network cards to communicate and creates a bridge between wireless networks and wired ones. A device that provides a connection between wireless devices and can connect to wired networks, implementing an infrastructure mode WLAN.

Answer 64

Wireless access point (AP)

Question 65

This layer is responsible for moving data around a network of networks, known as an internetwork. moves information around an internetwork by using logical network and host IDs.

Answer 65

Layer 3 is the Network layer.

Question 66

The main appliance working at layer 3 is ______

Answer 66

the router.

Question 67

A basic firewall operates at ______ to enforce an access control list (ACL). A network ACL is a list of the addresses and types of traffic that are permitted or blocked.

Answer 67

layer 3

Question 68

also known as the end-to-end or host-to-host layer. One of the functions of the Transport layer is to identify each type of network application by assigning it a port number. For example, data requested from an HTTP web application can be identified as port 80, while data sent to an email server can be identified as port 25.

Answer 68

Transport layer - layer 4 of the OSI model

Question 69

can also implement reliable data delivery mechanisms, should the application require it. Reliable delivery means that any lost or damaged packets are resent.

Answer 69

The Transport layer

Question 70

Devices working at the____ include multilayer switches - usually working as load balancers - and many types of security appliances, such as more advanced firewalls and intrusion detection systems (IDSs).

Answer 70

Transport layer

Question 71

Most application protocols require the exchange of multiple messages between the client and server. This exchange of such a sequence of messages is called a _______._______represents functions that administer the process of establishing a _____, managing data transfer, and then ending (or tearing down) ________.

Answer 71

session or dialog; The Session layer (layer 5); dialog; session

Question 72

transforms data between the format required for the network and the format required for the application. is used for character set conversion, such as between American Standard Code for Information Interchange (ASCII) and Unicode.

Answer 72

The Presentation layer (layer 6)

Question 73

is at the top of the OSI stack. provide an interface for software programs on network hosts that have established a communications channel through the lower-level protocols to exchange data. OSI model layer providing support to applications requiring network services (file transfer, printing, email, databases, and so on).

Answer 73

The Application layer (layer 7)

Question 74

Which of the following functions are performed by the OSI Transport layer? (Select three.) Packet formatting for delivery through a medium -Data segmentation and reassembly -End-to-end flow control -Path identification and selection -Reliable message delivery -Media access control, logical topology, and device identification -Consistent data formatting between dissimilar systems

Answer 74

-Data segmentation and reassembly -End-to-end flow control -Reliable message delivery

Question 75

A communications engineer notices that every time it rains the signal becomes very degraded. Which layer of the OSI model is the engineer most likely troubleshooting? -Physical -Data Link -Transport -Application

Answer 75

-Physical The physical layer (PHY) of the OSI model (layer 1) is responsible for the transmission and receipt of the signals that represent bits of data from one node to another node. Wireless is one medium.

Question 76

is the term used to describe the form that data takes at each layer of the OSI model. As data traverses down the layers on the sending node, each layer encapsulates the data by adding its specific headers (and sometimes footers), creating a PDU appropriate for that layer. This process ensures that data can be correctly processed, transmitted, and understood at each stage of its journey. A chunk of data with protocol-specific headers added at each OSI layer

Answer 76

Protocol Data Unit (PDU)?

Question 77

is a category of LAN with a small number of computing hosts that typically rely on a single integrated appliance for local and Internet connectivity.

Answer 77

Small office/home office (SOHO)

Question 78

one of its primary functions is to forward traffic between the LAN and the WAN

Answer 78

SOHO router

Question 79

Starting at layer 1, the SOHO router provides the following physical interfaces:

Answer 79

Radio antennae to transmit and receive wireless signals. A number of RJ45 ports, labeled as the LAN ports. A type of modem to connect to the ISP's network. labeled as the WAN port

Question 80

At layer 2, the SOHO router implements the following functions to make use of its Physical layer adapters:

Answer 80

Ethernet switch Wireless access point At this layer, each host interface is identified by a media access control (MAC) address.

Question 81

At layer 3, the Network layer, the routing part of the SOHO router:

Answer 81

makes forwarding decisions between the local private network and public Internet. These zones are distinguished by Internet Protocol (IP) addresses. The router runs a Dynamic Host Configuration Protocol (DHCP) server to allocate a unique address to each host that connects to it over either an Ethernet port or via the wireless access point.

Question 82

Transport and Application Layer and Security Functions for SOHO router:

Answer 82

The SOHO router can apply filtering rules to traffic sent between the public and private zones, implementing a firewall. The firewall can be configured to block traffic based on source or destination IP addresses and also on the type of application. At layer 4, each application is identified by a port number. The firewall in the router can be configured with rules specifying behavior for each port

Question 83

_______ is described as customer premises equipment (CPE)

Answer 83

The SOHO router

Question 84

Manages allocation of IP addresses and maintenance of the top-level domain space. currently run by Internet Corporation for Assigned Names and Numbers (ICANN). allocates addresses to regional registries that then allocate them to local registries or ISPs.

Answer 84

Internet Assigned Numbers Authority (IANA) (iana.org)

Question 85

Focuses on solutions to Internet problems and the adoption of new standards, published as Requests for Comments (RFCs). Some RFCs describe network services or protocols and their implementation, while others summarize policies. An older RFC is never updated. If changes are required, a new RFC is published with a new number. Not all RFCs describe standards. Some are designated informational, while others are experimental. The official repository for RFCs is at rfc-editor.org.

Answer 85

Internet Engineering Task Force (IETF) (ietf.org)

Question 86

decimal numbering is also referred to as ___; means that each digit can have one of ten possible values (0 through 9). A digit positioned to the left of another has 10 times the value of the digit to the right. For example, the number 255 can be written out as follows: (2x10x10)+(5x10)+5

Answer 86

base 10.

Question 87

Binary is ____, so a digit in any given position can only have one of two values (0 or 1), and each place position is the next power of 2. The binary value 11111111 can be converted to the decimal value 255 by the following sum: (1x2x2x2x2x2x2x2)+(1x2x2x2x2x2x2)+(1x2x2x2x2x2)+(1x2x2x2x2)+(1x2x2x2)+(1x2x2)+(1x2)+1

Answer 87

base 2

Question 88

is a convenient way of referring to the long sequences of bytes used in some other types of network addresses, such as hardware MAC addresses.

Answer 88

Hexadecimal notation (or hex

Question 89

Which of the following interfaces does a SOHO router provide at the Physical Layer of the OSI model? (Select three.) -WAN port for Internet Service Provider (ISP) connection -VGA ports for video output -Radio antennas for wireless signal transmission -USB ports for direct computer connection -SATA ports for internal storage connection -HDMI ports for multimedia streaming -RJ-45 ports for a local cabled network

Answer 89

-WAN port for Internet Service Provider (ISP) connection -Radio antennas for wireless signal transmission -RJ-45 ports for a local cabled network

Question 90

What do Internet Service Providers (ISPs) use to establish links between their networks within an Internet eXchange Point (IXP) data center? -Peer-to-peer file sharing -Transit and peering arrangements -Bluetooth connectivity -NFC (Near Field Communicatio

Answer 90

-Transit and peering arrangements Within an Internet eXchange Point (IXP) data center, ISPs establish links between their networks using transit and peering arrangements. These arrangements allow them to carry traffic to and from parts of the Internet they do not physically own, facilitating the exchange of internet traffic between different ISPs' networks.

Question 91

Which of the following BEST describes a demarcation point in the context of telecommunications? -The maximum data transfer rate achievable by the ISP -The central hub where all ISPs connect and exchange data -The point at which the telco's cabling enters the customer premises -The protocol used for encrypting data over the Internet

Answer 91

-The point at which the telco's cabling enters the customer premises The demarcation point (often shortened to "demarc") is the point where the telecommunications company's (telco's) responsibility ends and the customer's responsibility begins; typically where the telco's cabling enters the building or premises.

Question 92

Which of the following functions does a SOHO router implement at layer 2 to make use of its Physical layer adapters? (Select two.) -Firewall -Ethernet switch -Wireless access point -Network Address Translation (NAT) -DHCP server

Answer 92

-Ethernet switch -Wireless access point The following are the functions that a SOHO router implements: Ethernet switch. The RJ-45 jacks on a SOHO router are connected internally by an Ethernet switch, allowing multiple wired devices to communicate within the same network segment. This is a key function at layer 2, facilitating the use of Physical layer adapters for wired connections. Wireless access point. A SOHO router includes a wireless access point, which uses radio antennas to implement a version of the Wi-Fi standard. This allows wireless devices such as PCs, tablets, smartphones, and printers to form a network. The access point is also connected to the Ethernet switch internally, bridging the wired and wireless segments into a single logical data link network.

Question 93

What is the decimal form of the following binary IP address? 11001101.00111001.10101001.01000010 -206.58.170.67 -205.57.169.66 -238.90.202.99 -190.42.154.51

Answer 93

-205.57.169.66 To convert from binary to decimal, use the decimal equivalent of the following binary numbers: 10000000: 128 01000000: 64 00100000: 32 00010000: 16 00001000: 8 00000100: 4 00000010: 2 00000001: 1 To find the decimal form of a binary number, add up each decimal equivalent for each 1 bit in the address. For example, the equation for the number 11001101 is 128 + 64 + 8 + 4 + 1 = 205.

Question 94

CompTIA Network+ troubleshooting methodology:

Answer 94

1. Identify the problem 2. Establish a theory of probable cause 3. Test the theory to determine cause 4. Establish a plan of action to resolve the problem and ID potential effects 5. Implement the solution or escalate as necessary 6. Verify full system functionality and implement preventive measures 7. Document findings, actions, outcomes, and LL

Question 95

Which of the following MOST correctly describes using the divide and conquer approach of the OSI model for troubleshooting network issues? -Starting the troubleshooting process at the Physical Layer (Layer 1) and sequentially checking each layer until the Application Layer (Layer 7) is reached -Focusing solely on the Application Layer (Layer 7) to identify and resolve any software-related issues before considering network infrastructure problems -Identifying the most likely layer causing the issue based on symptoms and preliminary information, then working either up or down the OSI model as needed to isolate and resolve the problem -Checking all layers of the OSI model simultaneously to quickly identify and resolve network issues without considering the logical order of the layers

Answer 95

-Identifying the most likely layer causing the issue based on symptoms and preliminary information, then working either up or down the OSI model as needed to isolate and resolve the problem

Question 96

_______ works by modulating the properties of a transmission medium—electric current, infrared light, or radio waves—to encode a signal.

Answer 96

Network data transfer

Question 97

Higher frequencies allow for more data to be transferred per second. The range of frequencies is referred to as the _____

Answer 97

media bandwidth.

Question 98

refers to the methods a network technology uses to determine when nodes can communicate on shared media and to deal with possible problems, such as two devices attempting to communicate simultaneously.

Answer 98

Media access control (MAC)

Question 99

Network segment where nodes are attached to the same shared access media, such as a bus network or Ethernet hub.

Answer 99

collision domain

Question 100

The Ethernet protocol governing contention and media access is called ____

Answer 100

Carrier Sense Multiple Access with Collision Detection (CSMA/CD).

Question 101

100BASE-TX refers to ______ working over Cat 5 (or better) twisted pair copper cable with a maximum supported link length of 100 meters (328 feet). raising the bit rate from 10 Mbps to 100 Mbps.

Answer 101

Fast Ethernet

Question 102

To support compatibility with hosts still equipped with 10 Mbps Ethernet interfaces, Fast Ethernet introduced an ________ to allow a host to choose the highest supported connection parameters (10 or 100 Mbps and half- or full-duplex).

Answer 102

autonegotiation protocol

Question 103

10GBASE-T UTP (Cat 6) F/UTP (Cat 6A) S/FTP (Cat 7)

Answer 103

55 m (180 feet) 100 m (328 feet) 100 m (328 feet)

Question 104

40GBASE-T S/FTP (Cat 8)

Answer 104

30 m (100 feet)

Question 105

uses infrared light signals. The light signals are also not susceptible to interference or noise from other sources and less effected by attenuation. supports higher bandwidth over longer links than copper cable.

Answer 105

Fiber optic cable

Question 106

100BASE-FX

Answer 106

Optics - 1300 nm Cable - MMF (OM1) Max Dist. - 4km (2.48miles) Connectors - ST, SC, MT-RJ

Question 107

100BASE-SX

Answer 107

Optics -850 nm Cable -MMF (OM1), MMF (OM2) Max Dist - 300 m (984 feet) Connectors - ST, SC, LC

Question 108

1000BASE-SX

Answer 108

Optics - 850 nm Cable - MMF (OM1), MMF (OM2), MMF (OM3) Max Dist. - MMF (OM1) 275 m (902 feet), 550 m (1804 feet) Connectors - ST, SC, LC, MT-RJ

Question 109

1000BASE-LX

Answer 109

Optics -1,300 nm, 1,310 nm Cable -MMF (OM1/OM2/OM3), SMF (OS1/OS2) Max Dist. - 550 m (1,804 feet), 5 km (3.1 miles) Connectors - SC, LC

Question 110

10GBASE-SR

Answer 110

Optics - 850 nm Cable - MMF (OM1) 33 m (108 feet), MMF (OM2) 82 m (269 feet), MMF (OM3) 300 m (984 feet), MMF (OM4) 400 m (1,312 feet) Connectors - SC, LC

Question 111

10GBASE-LR

Answer 111

Optics - 1,310 nm Cable - SMF (OS1/OS2) Max Dist. - 10 km (6.2 miles) connectors - SC, LC

Question 112

For what reason might a company deploy 10/40 GbE Ethernet in its network? -To reduce overall network costs -To support very high bandwidth data transfers -To meet the standard for all new installations -To avoid using fiber optic cable

Answer 112

-To support very high bandwidth data transfers A company might deploy 10/40 GbE Ethernet in its network to support very high bandwidth data transfers, which could be required for business operations such as TV and film production. 10/40 GbE might be used where a company's business requires very high bandwidth data transfers.

Question 113

is a phenomenon whereby one pair causes interference in another as a result of their proximity.

Answer 113

Crosstalk

Question 114

uses a single thick wire per conductor and is used for cables that run behind walls or through ducts. uses thicker 22 to 24 AWG

Answer 114

Solid cabling

Question 115

uses thin filament wires wrapped around one another and is used to make flexible patch cords for connecting computers to wall ports and switch ports to patch panel ports. often 26 AWG

Answer 115

Stranded cabling

Question 116

Copper wire thickness is measured using

Answer 116

American Wire Gauge (AWG)

Question 117

has one thin outer foil shield around all pairs.

Answer 117

Screened cable; usually designated as screened twisted pair (ScTP) or foiled/unshielded twisted pair (F/UTP), or sometimes just foiled twisted pair (FTP).

Question 118

has a braided outer screen and foil-shielded pairs

Answer 118

Fully shielded cabling; shielded/foiled twisted pair (S/FTP). There are also variants with a foil outer shield (F/FTP)

Question 119

able has foil-shielded pairs but no outer shield.

Answer 119

U/FTP

Question 120

Cat5e (class D)

Answer 120

cable type -UTP or F/UTP Ethernet standard - 1000BASE-T Max Dist. - 100 m (328 ft) Frequency -100 MHz Connector- RJ45

Question 121

Cat6 (class E)

Answer 121

cable type -UTP, F/UTP, or U/FTP Ethernet standard - 1000BASE-T 100 m (328 ft), 10GBASE-T 55 m (180 ft) Frequency - 250 MHz connector - RJ45

Question 122

Cat 6A (class Ea)

Answer 122

cable type -UTP, F/UTP, U/FTP, or S/FTP Ethernet standard -10GBASE-T Max Dist. -100 m (328 ft) Frequency -500 MHz Connector - RJ45

Question 123

Cat 7 (class F)

Answer 123

cable type -S/FTP or F/FTP Ethernet standard -10GBASE-T Max Dist. - 100 m (328 ft) Frequency -600 MHz Connector - GG45/TERA

Question 124

Cat 8/8.1 (class I)

Answer 124

Cable type - F/FTP or S/FTP Ehternet standard -40GBASE-T Max Dist. - 30 m (100 ft) Frequency -2,000 MHz Connector - GG45/TERA

Question 125

is a void in a building designed to carry heating, ventilation, and air conditioning (HVAC) systems. is typically a false ceiling, though it could also be constructed as a raised floor.

Answer 125

A plenum space

Question 126

is made of two conductors that share the same axis. The core conductor is made of solid or stranded copper wire and is enclosed by plastic insulation. A wire mesh wrapped around the plastic constitutes the second conductor. This serves as shielding from interference.

Answer 126

Coaxial (or coax) cable

Question 127

is similar to coax but contains two inner conductors. Twinax is used for datacenter interconnects working at 10 GbE (unofficially referred to as 10GBASE-CR) and 40 GbE (40GBASE-CR4). maximum distance is up to about 5 meters for passive cable types and 10 meters for active cable types.

Answer 127

Twinaxial (or twinax)

Question 128

What is the main difference between screened cabling and fully shielded cabling? -Screened cabling uses a braided outer screen only. -Fully shielded cabling uses foil-shielded pairs without an outer shield. -Screened cabling has one thin outer foil shield around all pairs. -Fully shielded cabling has no shielding at all.

Answer 128

-Screened cabling has one thin outer foil shield around all pairs.

Question 129

Which type of conductor wire is typically used for cables that run behind walls or through ducts? -Stranded -Solid -Coaxial -Fiber optic

Answer 129

-Solid Solid cabling uses a single thick wire per conductor and is used for permanent installations that run behind walls or through ducts because of its lower attenuation over longer distances. Stranded conductor wires are used to make flexible patch cords for connecting devices, not for permanent installations behind walls or through ducts.

Question 130

In a telephone system, what is the primary function of the center two contacts in an RJ11 connector? -They are used to provide power to the telephone unit. -They carry the dial tone and voice circuit. -They are reserved for future technological advancements. -They enhance the signal quality for internet connections.

Answer 130

-They carry the dial tone and voice circuit.

Question 131

Which of the following statements is true regarding the use of plenum-rated cables in place of riser-rated cables? -Plenum-rated cables can never be used in place of riser-rated cables due to their different fire safety standards. -Plenum-rated cables can be used in place of riser-rated cables, but not vice versa. -Riser-rated and plenum-rated cables are interchangeable with no restrictions. -Using plenum-rated cables in place of riser-rated cables reduces the overall bandwidth of the network.

Answer 131

-Plenum-rated cables can be used in place of riser-rated cables, but not vice versa. Plenum-rated cables are designed to meet stricter fire safety standards than riser-rated cables, making them suitable for use in more demanding environments, such as plenum spaces. Because of these higher standards, plenum-rated cables can be used in applications requiring riser-rated cables, but the reverse is not true due to the lower fire safety standards of riser-rated cables. Riser-rated cables cannot be used in place of plenum-rated cables due to the lower fire safety standards of riser-rated cables. The interchangeability is not reciprocal.

Question 132

Which organizations have created categories of cable standards for twisted pair to simplify the selection of a suitable quality cable? -IEEE and IETF -ANSI and TIA/EIA -ISO and IEC -ITU and ETS

Answer 132

-ANSI and TIA/EIA The American National Standards Institute (ANSI) and the Telecommunications Industry Association (TIA)/Electronic Industries Alliance (EIA) are responsible for creating categories of cable standards for twisted pair cables. This simplifies the process of selecting a suitable quality cable for telecommunications purposes.

Question 133

ANSI/TIA/EIA 568 Commercial Building Telecommunications Wiring Standard.

Answer 133

Work Area Horizontal Cabling Telecommunications Room Backbone Cabling Entrance Facilities/Demarc

Question 134

The space where user equipment is located and connected to the network, usually via a patch cable plugged into a wall port.

Answer 134

Work Area

Question 135

Connects user work areas to an intermediate distribution frame (IDF). it typically consists of the cabling for a single floor and so is made up of cables run horizontally through wall ducts or ceiling spaces. When using copper cabling, the IDF must be within 90 m (295 feet) cabling distance of each wall port. If this is not possible, multiple IDFs must be provisioned. Multiple IDFs on the same floor are linked by horizontal cross connects.

Answer 135

Horizontal Cabling

Question 136

Room or closet that houses an intermediate distribution frame and networking equipment, such as switches. Essentially, this is a termination point for the horizontal cabling along with a connection to backbone cabling. This wiring closet must be used only for networking equipment (not general storage) and should ideally be secured by a lockable door.

Answer 136

Telecommunications Room

Question 137

Connects IDFs to a main distribution frame (MDF). also referred to as vertical cabling, as it is more likely to run up and down between floors.

Answer 137

Backbone Cabling

Question 138

Special type of telecommunications room marking the point at which external cabling is joined to internal cabling, via the MDF. Entrance facilities are required to join the local exchange carrier's (LEC's) network and for inter-building communications. The demarcation point is where the access provider's network terminates and the organization's network begins.

Answer 138

Entrance Facilities/Demarc

Question 139

EIA/TIA 568 A Standard

Answer 139

1- green with stripes 2 - green 3 - orange with stripes 4 - blue 5 - blue with stripes 6 - orange 7 - brown with stripes 8 - brown

Question 140

EIA/TIA 568 B Standard

Answer 140

1 - orange with stripes 2 - orange 3 - green with stripes 4 - blue 5 - blue with stripes 6 - green 7 - brown with stripes 8 - brown

Question 141

Type of distribution frame used with twisted pair cabling with IDCs to terminate fixed cabling on one side and modular jacks to make cross-connections to other equipment on the other. Also called a patch bay.

Answer 141

a patch panel

Question 142

Installing structured cable from a bulk spool is referred to as ______ because the cable must be pulled, carefully, from the telecommunications closet to the work area.

Answer 142

pulling cable

Question 143

A single optical fiber is constructed from three elements:

Answer 143

Core provides the transmission path, or waveguide, for the light signals. Cladding reflects signals back into the waveguide as efficiently as possible. Buffer is a protective plastic coating.

Question 144

In basic operation modes, each fiber optic strand can only transfer light in a single direction at a time.

Answer 144

Therefore, multiple fibers are often bundled within a cable to allow simultaneous transmission and reception of signals or to provide links for multiple applications.

Question 145

has a small core (8 to 10 microns) and a long wavelength. It uses a laser to generate a near infrared (1,310 nm or 1,550 nm) light signal. support data rates up to 100 Gbps and cable runs of many kilometers, depending on the quality of the cable and optics. OS1 is designed for indoor use, while OS2 is for outdoor deployment.

Answer 145

Single Mode Fiber (SMF)

Question 146

has a larger core (62.5 or 50 microns) and shorter wavelength light (850 nm or 1,300 nm) transmitted in multiple waves of varying length. uses less expensive optics and consequently is less expensive to deploy. it does not support such high signaling speeds or long distances as single mode and so is more suitable for LANs than WANs.

Answer 146

Multimode Fiber (MMF)

Question 147

Classification system for multimode fiber designating core size and modal bandwidth.

Answer 147

optical multimode (OM) categories

Question 148

OM1/OM2

Answer 148

62.5-micron cable is OM1, while early 50-micron cable is OM2. OM1 and OM2 are mainly rated for applications up to 1 Gbps and use LED transmitters.

Question 149

OM3/OM4

Answer 149

These are also 50-micron cable, but manufactured differently, designed for use with 850 nm vertical-cavity surface-emitting lasers (VCSEL), also referred to as laser optimized MMF (LOMMF). A VCSEL is not as powerful as a laser type used for SMF, but it supports higher modulation (transmitting light pulses rapidly) than LED-based optics.

Question 150

is an early bayonet-style connector that uses a push-and-twist locking mechanism. ST was used mostly for multimode networks, but it is not widely used for Ethernet installations anymore.

Answer 150

Fiber optic connector -Straight Tip (ST)

Question 151

is a push/pull design, allowing for simple insertion and removal. It can be used for single- or multimode. It is commonly used for Gigabit Ethernet.

Answer 151

fiber optic connector - The Subscriber Connector (SC)

Question 152

is a small-form-factor connector with a tabbed push/pull design. similar to SC, but the smaller size allows for higher port density. is a widely adopted form factor for Gigabit Ethernet and 10/40 GbE.

Answer 152

fiber optic connector - The Local Connector (LC) (also referred to as Lucent Connector)

Question 153

The faces of the connector and fiber tip are polished so that they reduce back reflection, curve slightly, and fit together better.

Answer 153

Ultra Physical Contact (UPC)

Question 154

The faces are angled for an even tighter connection. APC cannot be mixed with PC or UPC.

Answer 154

Angled Physical Contact (APC)

Question 155

OM1 OM2 OM3/OM4 SMF PC/UPC SMF APC

Answer 155

Orange Beige Orange Black Aqua Aqua Yellow Blue Yellow Green

Question 156

Type of distribution frame with pre-wired connectors used with fiber optic cabling.

Answer 156

fiber distribution panel

Question 157

Fiber optic cable type that terminates multiple strands to a single compact connector, supporting parallel links. termination allows for low-footprint backbone or trunk cabling. backbone ribbon cable bundles 12 or more strands terminated to a single compact ferrule.

Answer 157

Multi-fiber push-on (MPO)

Question 158

uses one transmit lane and one receive lane and requires two fiber strands.

Answer 158

A duplex fiber channel link

Question 159

uses bundles of lanes working at 10 Gbps or 25 Gbps to implement 40 Gbps or 100 Gbps links. These channel links require between eight and twenty strands.

Answer 159

Parallel fiber

Question 160

is a means of using one or two strands to provision multiple channels.

Answer 160

Wavelength Division Multiplexing (WDM)

Question 161

support transmit and receive signals over the same strand of fiber. must be installed in opposite pairs, so the downstream transceiver would have to use 1,490 nm for Tx and 1,310 for Rx.

Answer 161

Bidirectional (BiDi) transceivers

Question 162

System that allows bidirectional data transfer over a single fiber strand by using separate wavelengths for transmit and receive streams.

Answer 162

Bidirectional wavelength division multiplexing (BWDM)

Question 163

supports up to 16 wavelengths and is typically used to deploy four or eight bidirectional channels over either a single fiber strand or unidirectional channels over dual fiber strands (one strand for transmit, the other for receive). transceivers support multi-channel 1 G, 10 G, and 40 G Ethernet links. The transceivers must be installed in opposite pairs.

Answer 163

Coarse Wavelength Division Multiplexing (CWDM)

Question 164

provisions greater numbers of channels (20, 40, 80, or 160). This means that there is much less spacing between each channel and that it requires more precise and expensive lasers. transceivers support multi-channel 1 G, 10 G, and 40 G Ethernet links. The transceivers must be installed in opposite pairs.

Answer 164

Dense Wavelength Division Multiplexing (DWDM)

Question 165

What is the primary purpose of Wavelength Division Multiplexing (WDM)? -To reduce the bandwidth of individual channels -To provision multiple channels over one or two strands of fiber -To increase the latency of data transmission -To decrease the overall data transmission rate

Answer 165

-To provision multiple channels over one or two strands of fiber. WDM allows for the transmission of multiple data channels over a single or dual fiber strand(s) by using different wavelengths for each channel, thereby increasing the capacity of the fiber without needing additional strands.

Question 166

What is a major difference when comparing Dense Wavelength Division Multiplexing (DWDM) to CWDM? -DWDM supports fewer channels than CWDM. -DWDM requires less precise lasers than CWDM. -DWDM provisions greater numbers of channels with much less spacing between each channel. -DWDM is typically used for shorter distance transmissions than CWDM.

Answer 166

-DWDM provisions greater numbers of channels with much less spacing between each channel. DWDM can support a higher number of channels (20, 40, 80, or 160) by using much tighter wavelength spacing, requiring more precise and expensive lasers compared to CWDM.

Question 167

What does Bidirectional Wavelength Division Multiplexing (BiDi) use to support transmit and receive signals over the same strand of fiber? -Identical wavelengths for Tx and Rx signals -Slightly shifted wavelengths for Tx and Rx signals -Increased power levels for Tx signals only -Decreased power levels for Rx signals only

Answer 167

-Slightly shifted wavelengths for Tx and Rx signals. BiDi transceivers use slightly different wavelengths for transmitting (Tx) and receiving (Rx) signals over the same fiber strand, such as 1310 nm for Tx and 1490 nm for Rx, allowing for bidirectional communication on a single strand.

Question 168

How does an MPO connector capable of carrying 24 or 32 fibers compare in footprint to a duplex LC pair? -It requires more space than a duplex LC pair. -It has the same footprint as a duplex LC pair. -It is only suitable for single-mode fibers. -It is twice as large as a duplex LC pair.

Answer 168

-It has the same footprint as a duplex LC pair. An MPO connector, even when capable of carrying 24 or 32 fibers, has the same footprint as a duplex LC pair. This compact design allows for high-density fiber connections without requiring additional space.

Question 169

How many fiber strands are required for a 40 Gbps link comprising 4 x 10 Gbps lanes using Multi-fiber Push On (MPO) connectors? 4 strands 8 strands 12 strands 16 strands

Answer 169

8 strands A 40 Gbps link comprising 4 x 10 Gbps lanes requires eight strands because each 10 Gbps lane requires two fiber strands (one for sending and one for receiving). Therefore, for 4 lanes, the total is 4 lanes x 2 strands per lane = 8 strands. This efficient use of strands is one of the advantages of MPO connectors in aggregating multiple lanes into a single optical link.

Question 170

What does the TIA/EIA cabling standard require for fiber patch cord polarity? -An even number of elements in the link, such as two patch cords and two permanent links -No requirement for crossover in the link elements -A direct connection without the use of patch cords -An odd number of elements in the link, such as two patch cords and a permanent link

Answer 170

-An odd number of elements in the link, such as two patch cords and a permanent link. The TIA/EIA cabling standard specifies that for maintaining correct fiber patch cord polarity, there must be an odd number of elements in the link. This configuration ensures that the correct polarity is maintained from one end of the connection to the other. The elements typically include patch cords and a permanent link. Having an odd number of elements ensures that a crossover occurs at each connection point, correctly aligning the transmit (Tx) and receive (Rx) signals.

Question 171

How can you identify transmitted optical signals when working with fiber optic patch cords? -By listening for a distinct sound emitted by the fiber optic cable -By feeling the temperature change on the surface of the cable -By observing bright white spots through a smartphone camera -By measuring the weight of the fiber optic cable

Answer 171

-By observing bright white spots through a smartphone camera. When working with fiber optic patch cords, transmitted optical signals can be identified by observing bright white spots through a smartphone camera. This method leverages the camera's sensitivity to the specific wavelength of light transmitted through the fiber. While the human eye cannot directly see these light wavelengths, a smartphone camera can detect them, appearing as bright white spots on the camera's display. This technique is a practical way to identify which fiber is actively transmitting light, aiding in troubleshooting and verifying connections.

Question 172

Multi-mode fiber is designed to operate at which of the following wavelengths? -850 nm and 1300 nm -1310 nm and 1550 nm -850 nm and 1310 nm -1300 nm and 1550 nm

Answer 172

-850 nm and 1300 nm Multi-mode fiber is designed to operate at 850 nm and 1300 nm. Single-mode fiber is optimized for 1310 nm and 1550 nm.

Question 173

is a specially configured steel shelving system designed for standard-size equipment. Using a rack allows equipment to be stored more securely and compactly than ordinary desks or shelving would allow for. The concept of installing more computing appliances in a smaller space is referred to as density.

Answer 173

A rack

Question 174

Rack height is measured in

Answer 174

"U" units of 1.75" / 4.45 cm. Racks are sold in heights from 8U to 48U. Rack-compatible equipment is designed with a vertical height quoted in U so you can plan exactly how much vertical space you require.

Question 175

Multiple rows should be placed back-to-back not front to back to maximize cooling. This is referred to as a _____

Answer 175

hot aisle/cold aisle layout.

Question 176

Sensors can also be installed to measure ambient environmental conditions for a network rack or enclosure or within a server room or equipment closet. The following environmental factors need monitoring:

Answer 176

Temperature Humidity Electrical Flooding

Question 177

An advanced strip socket that provides filtered output voltage. A managed unit supports remote administration. has circuitry to "clean" the power signal, provides protection against spikes, surges, and under-voltage events, and can integrate with an uninterruptible power supply (UPS).

Answer 177

power distribution unit (PDU)

Question 178

will provide a temporary power source in the event of a power failure. runtime may range from a few minutes for a desktop-rated model to hours for an enterprise system.

Answer 178

uninterruptible power supply (UPS

Question 179

works on the principle that a fire requires heat, oxygen, and fuel to ignite and burn.

Answer 179

The fire triangle

Question 180

_____ fire extinguishers are designed to combat fires fueled by ordinary combustible materials like wood, paper, cloth, and plastics

Answer 180

Class A

Question 181

_______ extinguishers use gas-based extinguishing and can be used where the risk of electric shock makes other types unsuitable

Answer 181

Class C

Question 182

These are used in areas where freezing is possible; water only enters this part of the system if sprinklers elsewhere are triggered.

Answer 182

Dry-pipe

Question 183

A pre-action system only fills with water when an alarm is triggered; it will then spray when the heat rises. This gives protection against accidental discharges and burst pipes and gives some time to contain the fire manually before the sprinkler operates.

Answer 183

Pre-action

Question 184

Gas-based systems have the advantage of not short circuiting electrical systems and leaving no residue. has been banned in most countries as it is ozone depleting, though existing installations have not been replaced in many instances and can continue to operate legally.

Answer 184

Halon

Question 185

As well as not being environmentally damaging, these gases are considered nontoxic to humans. Examples include INERGEN (a mixture of CO2, Argon, and Nitrogen), FM-200/HFC-227, and FE-13. The gases both deplete the concentration of oxygen in the area (though not to levels dangerous to humans) and have a cooling effect. CO2 can be used too, but it is not safe for use in occupied areas.

Answer 185

Clean agent

Question 186

Which of the following is a correct statement about the installation of rack-mounted appliances? -Appliances should always be installed on the topmost rack for easy access. -Appliances can be screwed directly into the rack if there is little need for maintenance. -All appliances must be installed using rail kits for safety reasons. -Non-standard components cannot be installed in racks under any circumstances.

Answer 186

-Appliances can be screwed directly into the rack if there is little need for maintenance.

Question 187

What is the primary function of blanking plates in a rack system? -To provide additional support to the equipment -To improve airflow -To enhance the aesthetic appearance of the rack -To increase the rack's weight capacity

Answer 187

-To improve airflow

Question 188

Which of the following do internal sensors within servers and appliances normally monitor? (Select three.) -Length of Ethernet cables connected to the device -Excessive temperatures within the device chassis -Brand of RAM installed in the device -Weight of the server rack -Physical location of Wi-Fi routers -Fan speeds -Component failure

Answer 188

-Fan speeds -Component failure -Excessive temperatures within the device chassis

Question 189

What type of sprinkler system holds water at high pressure and discharges water when triggered by heat? -Dry-pipe -Pre-action -Wet-pipe -Halon

Answer 189

-Wet-pipe Wet-pipe sprinkler systems constantly hold water at high pressure and discharge water when triggered by heat, making them quick to respond to fires. Dry-pipe systems are used in areas where freezing is possible. Pre-action systems require an alarm trigger before filling with water. Halon is a gas-based fire suppression system.

Question 190

In a high-rise office building, the fire alarm system detects smoke on one of the floors. The building is equipped with a sophisticated fire suppression system that includes automatic smoke detectors, manual alarm points, and a combination of wet-pipe and pre-action sprinkler systems. The fire is located in a storage room filled with paper products, which is adjacent to the server room. Given the situation, which immediate action should the building's fire safety team prioritize to effectively manage the fire while minimizing potential damage to the server room? -Activate the wet-pipe sprinkler system throughout the entire building. -Use portable Class A fire extinguishers to control the fire in the storage room. -Immediately release the clean agent fire suppression system in the server room. -Manually activate the pre-action sprinkler system in the storage room only.

Answer 190

-Use portable Class A fire extinguishers to control the fire in the storage room

Question 191

The number of symbols that can be transmitted per second is called the _____The _____ is measured in hertz (or MHz or GHz).

Answer 191

baud rate.

Question 192

is an average data transfer rate achieved over a period of time excluding encoding schemes, errors, and other losses incurred at the Physical and Data Link layers. can be adversely affected by link distance and by interference (noise).

Answer 192

Throughput

Question 193

Speed is measured as a unit of time—typically milliseconds (ms)—and is also referred to as __, or delay.

Answer 193

latency

Question 194

is the loss of signal strength, expressed in decibels (dB). dB expresses the ratio between two measurements; in this case, signal strength at origin and signal strength at destination.

Answer 194

Attenuation

Question 195

(or noise) is anything that gets transmitted within or close to the channel that isn't the intended signal. This serves to make the signal itself difficult to distinguish, causing errors in data and forcing retransmissions. This is expressed as the signal to noise ratio (SNR).

Answer 195

Interference

Question 196

device can be used to detect improper termination issues. the base unit is connected to one end of the cable and a remote unit to the other. When the test is activated, an LED for each wire conductor lights up in sequence. If an LED fails to light or does not light in sequence, there is a problem with the cable and/or termination.

Answer 196

wire map tester device

Question 197

Wire map testers can identify the following problems:

Answer 197

Continuity (open) Short Incorrect pin-out/incorrect termination/mismatched standards Reversed pair Crossed pair (TX/RX transposed)

Question 198

A conductor does not form a circuit because of cable damage or because the connector is not properly wired.

Answer 198

Continuity (open)

Question 199

Two conductors are joined at some point, usually because the insulating wire is damaged, or a connector is poorly wired.

Answer 199

Short

Question 200

The conductors are incorrectly wired into the terminals at one or both ends of the cable. The following transpositions are common:

Answer 200

Incorrect pin-out/incorrect termination/mismatched standards

Question 201

The conductors in a pair have been wired to different terminals (for example, from pin 3 to pin 6 and pin 6 to pin 3 rather than pin 3 to pin 3 and pin 6 to pin 6).

Answer 201

Reversed pair

Question 202

The conductors from one pair have been connected to pins belonging to a different pair (for example, from pins 3 and 6 to pins 1 and 2). This may be done deliberately to create a crossover cable, but such a cable would not be used to link a host to a switch.

Answer 202

Crossed pair (TX/RX transposed)

Question 203

This is where both ends of a single wire in one pair are wired to terminals belonging to a different pair. This type of fault can only be detected by a cable tester that measures crosstalk.

Answer 203

split pair

Question 204

may mean that the link experiences signal degradation problems with high error rates and retransmissions (frame or packet loss) resulting in reduced speeds and possibly loss of connectivity.

Answer 204

decibel (dB) loss (or insertion loss)

Question 205

usually indicates a problem with bad wiring (poor quality or damaged or the improper type for the application), a bad connector, or improper termination. Crosstalk

Answer 205

Crosstalk

Question 206

This measures crosstalk on the receive pairs at the transmitter end and is usually caused by excessive untwisting of pairs or faulty bonding of shielded elements.

Answer 206

Near End (NEXT)

Question 207

This is the difference between insertion loss and NEXT. ACR is equivalent to a signal-to-noise ratio (SNR). A high value means that the signal is stronger than any noise present; a result closer to zero means the link is likely to be subject to high error rates.

Answer 207

Attenuation to Crosstalk Ratio, Near End (ACRN)

Question 208

Far-end crosstalk (FEXT) is measured on the receive pairs at the recipient end. The difference between insertion loss and FEXT gives ACRF, which measures cable performance regardless of the actual link length.

Answer 208

Attenuation-to-Crosstalk Ratio, Far End (ACRF)

Question 209

Gigabit and 10 GbE Ethernet use all four pairs. Power sum crosstalk calculations (PSNEXT, PSACRN, and PSACRF) confirm that a cable is suitable for this type of application. They are measured by energizing three of the four pairs in turn.

Answer 209

Power Sum

Question 210

This is signal traffic from cables in close proximity that causes interference to a disturbed or victim cable. This is commonly caused by cinching a cable bundle with ties too tightly and by poorly terminated cabling.

Answer 210

Alien Crosstalk

Question 211

Troubleshooting tool used to identify breaks or imperfections in fiber optic cable. The tool shines visible light down the cable and glows brightly at the point where a cable is broken, excessively bent, or improperly spliced.

Answer 211

visual fault locator

Question 212

You are preparing to deploy a new fiber optic link that requires minimal signal loss and very low back-reflection due to the sensitivity of the connected equipment. Which type of connector polish should you ensure is used for this installation? -Ultra Physical Contact (UPC) -Physical Contact (PC) -Angled Physical Contact (APC) -Straight Physical Contact (SPC)

Answer 212

-Angled Physical Contact (APC) Angled Physical Contact (APC) is the correct answer. APC connectors are designed to minimize back-reflection (optical return loss) by angling the end of the fiber. This is crucial for applications requiring minimal signal loss and low back-reflection, making it the best choice for sensitive equipment.

Question 213

What does Power Sum Crosstalk measure? -The total interference from all other cables in a bundle -Crosstalk on the transmit pairs at the receiver end -The suitability of a cable for Gigabit and 10 GbE Ethernet applications -The difference between insertion loss and Far End Crosstalk (FEXT)

Answer 213

-The suitability of a cable for Gigabit and 10 GbE Ethernet applications Power Sum Crosstalk calculations, including PSNEXT, PSACRN, and PSACRF, are used to confirm that a cable can adequately support applications like Gigabit and 10 GbE Ethernet, which utilize all four pairs of the cable.

Question 214

During a routine network audit, a technician discovers that the ethernet cables running next to the electrical power lines are experiencing higher error rates than those routed separately. What is the most likely explanation for the increased error rates in these cables? -The ethernet cables are too long. -The proximity to power lines is causing increased Attenuation -The cables are experiencing Alien Crosstalk from the power lines. -The ethernet cables are of poor quality.

Answer 214

-The cables are experiencing Alien Crosstalk from the power lines. The cables are experiencing Alien Crosstalk from the power lines is the correct answer. While not traditional Alien Crosstalk as it involves electrical interference rather than signal traffic from other data cables, the principle is similar. The electromagnetic interference from the power lines can disrupt the signal in the ethernet cables, leading to higher error rates.

Question 215

What is the maximum allowed insertion loss for Cat 5e at 100 MHz? 21.7 dB 24 dB 10 dB 30 dB

Answer 215

24 dB For Cat 5e cables at 100 MHz, the maximum allowed insertion loss is up to 24 dB. This value is specific to the cable category and frequency.

Question 216

The transceiver component responsible for physically connecting a host to the transmission medium is implemented in a

Answer 216

network interface card/controller (NIC), also referred to as a network adapter

Question 217

Each Ethernet network interface port has a unique hardware address known as the ______. is 48 bits long with the first half representing the manufacturer's organizationally unique identifier (OUI). Also called a client identifier. This may also be referred to as the Ethernet address (EA) or, in IEEE terminology, as the extended unique identifier (EUI). also referred to as a local or physical address.

Answer 217

Media Access Control (MAC) address.

Question 218

________ transceivers use LC connectors and support Gigabit Ethernet data rates. Fiber optic transceiver module type supporting duplex 1 Gbps (SFP) or 10 Gbps (SFP+) links.

Answer 218

Small form-factor pluggable (SFP)

Question 219

______ is a transceiver form factor that supports 4 x 1 Gbps links, typically aggregated to a single 4 Gbps channel. Fiber optic transceiver module type supporting four individual duplex lanes at 1 Gbps (QSFP) or 10 Gbps (QSFP+) that can be aggregated into a single 4 Gbps or 40 Gbps channel. QSFP+ is typically used with parallel fiber and multi-fiber push-on (MPO) termination. ______ + can also be used with Wavelength Division Multiplexing (WDM) Ethernet standards.

Answer 219

Quad small form-factor pluggable (QSFP)

Question 220

Modular transceivers are designed to be used with a specific type of optical fiber. For example, transceivers designed for single mode fiber use ______ while multimode fiber transceivers use ____

Answer 220

laser diodes; LEDs or a different type of laser (VCSEL).

Question 221

uses two strands for transmit (Tx) and receive (Rx).

Answer 221

Duplex

Question 222

uses multiple strands (typically eight or twenty) to implement Tx and Rx channels.

Answer 222

Parallel

Question 223

uses either a single bidirectional strand or dual unidirectional strands to implement multiple channels, distinguished by wavelengths.

Answer 223

Wavelength Division Multiplexing

Question 224

Assessment of allowable signal loss over a fiber optic link. or loss budget, is the amount of loss suffered by all components along a fiber transmission path. This is calculated using the following parameters: Attenuation, connectors, and splices.

Answer 224

An optical link budget

Question 225

This is the loss over the length of the cable, based on fiber type and the wavelength used. Single mode has a loss of up to 0.4 dB/km, while multimode can be from 0.8 dB/km to 3 dB/km.

Answer 225

Attenuation

Question 226

Each connector in the path incurs a loss, usually assumed to be 0.75 dB.

Answer 226

Connectors

Question 227

Additional splices in the cable are budgeted at around 1 dB for mechanical and 0.3 dB for fusion.

Answer 227

Splices

Question 228

Ethernet encapsulates the payload from higher layer protocols within a protocol data unit (PDU) called a ___

Answer 228

frame.

Question 229

basic format of an ethernet frame and ethernet header:

Answer 229

Preamble> SFD> Destination MAC > Source MAC> Ether Type> Payload > FCS

Question 230

are used for clock synchronization and as part of the CSMA/CD protocol to identify collisions. _____ consists of 8 bytes of alternating 1s and 0s with the _______ being two consecutive 1s at the end. This is not technically considered to be part of the frame.

Answer 230

The preamble and start frame delimiter (SFD); The preamble; SFD

Question 231

The 2-byte ___ field is usually used to indicate the type of protocol in the frame payload. For example, a frame carrying an IPv4 packet would have an _____ value of 0x0800; one carrying IPv6 data would be 0x86DD.

Answer 231

EtherType

Question 232

The error checking field contains a 32-bit (4-byte) checksum called a ____. is calculated based on the contents of the frame; the receiving node performs the same calculation and, if it matches, accepts the frame. There is no mechanism for retransmission if damage is detected nor is the ___ completely accurate at detecting damage; these are functions of error checking in protocols operating at higher layers.

Answer 232

cyclic redundancy check (CRC) or frame check sequence (FCS).

Question 233

The first six hex digits (3 bytes or octets), also known as the __________, identify the manufacturer of the adapter. The last six digits are a serial number.

Answer 233

organizationally unique identifier (OUI)

Question 234

The IEEE gives each network adapter manufacturer a range of numbers, and the manufacturer hard codes every interface produced with a unique number from their range. the universal address

Answer 234

Burned-in Addresses

Question 235

A packet addressed to a single host. If the host is not on the local subnet, the packet must be sent via one or more routers.

Answer 235

A unicast transmission

Question 236

Network segment in which all nodes receive the same broadcast frames at layer 2.

Answer 236

broadcast domain.

Question 237

Which optical wavelengths are typically supported by different transceivers? -650 nm, 850 nm, and 1300 nm -850 nm, 1300 nm, and 1550 nm -900 nm, 1200 nm, and 1600 nm -700 nm, 950 nm, and 1450 nm

Answer 237

-850 nm, 1300 nm, and 1550 nm Transceivers are designed to work at specific optical wavelengths to match the transmission characteristics of the optical fiber they are used with. The typical wavelengths supported are 850 nm, 1300 nm, and 1550 nm. These wavelengths are chosen based on their transmission properties, including minimal loss and dispersion over fiber optic cables.

Question 238

Which type of laser is typically used with single mode fiber transceivers? -LED -VCSEL -Laser diodes -Incandescent bulbs

Answer 238

-Laser diodesSingle mode fiber transceivers typically use laser diodes because they can provide the narrow beam and high power necessary for the long-distance transmission that single mode fibers support. Laser diodes are capable of transmitting data over longer distances with less signal loss compared to LEDs or VCSELs, which are more commonly used with multimode fibers.

Question 239

What is the function of duplex fiber deployment? -It uses a single strand for both transmit and receive. -It uses two strands for transmit (Tx) and receive (Rx). -It uses multiple strands to implement Tx and Rx channels. -It implements multiple channels distinguished by wavelengths

Answer 239

-It uses two strands for transmit (Tx) and receive (Rx).

Question 240

Which of the following is a unique identifier for each Ethernet network interface port? -IP address -MAC address -Serial number -Model number

Answer 240

-MAC address Explanation: Each Ethernet network interface port has a unique hardware address known as the Media Access Control (MAC) address, which is used to identify devices on a network.

Question 241

What is the primary purpose of a Multi-Source Agreement (MSA) in the context of modular transceivers? -To ensure compatibility between transceivers from different vendors -To increase the data transmission speed of transceivers -To decrease the cost of transceivers -To standardize the size of transceivers

Answer 241

-To ensure compatibility between transceivers from different vendors

Question 242

Which type of connectors do SFP transceivers use? -RJ-45 -LC -SC -MPO

Answer 242

-LC Small Form Factor Pluggable (SFP) transceivers use LC connectors, which are designed for fiber optic cables.

Question 243

A network administrator is configuring a new network interface card (NIC) for a server in a data center. The NIC has a default MAC address of 00:1A:2B:3C:4D:5E. However, due to specific network policies, the administrator needs to change this to a locally administered address. Which of the following addresses could the administrator use to comply with this policy? -02:1A:2B:3C:4D:5E -AA:BB:CC:DD:EE:FF -00:1A:2B:3C:4D:5F -FF:FF:FF:FF:FF:FF

Answer 243

-02:1A:2B:3C:4D:5E Changing the second least significant bit of the first byte to 1 (as in 02) indicates that the address is locally administered. This is the correct way to convert a universally administered address to a locally administered one.

Question 244

What does a MAC address of ff:ff:ff:ff:ff:ff signify? -A unicast transmission -A multicast transmission -A broadcast transmission -An invalid MAC address

Answer 244

-A broadcast transmission A MAC address consisting entirely of 'ff:ff:ff:ff:ff:ff' is the broadcast address, meaning the frame should be processed by all nodes within the same broadcast domain.

Question 245

_____ acts like a multiport repeater so that every port receives transmissions sent from any other port. As a repeater, the hub works only at the Physical layer.

Answer 245

A hub

Question 246

The end system interface is referred to as ____; the interface on the hub is referred to as MDI crossover (MDIX). This means that the transmit (Tx) wires on the host connect to receive (Rx) wires on the hub.

Answer 246

medium dependent interface (MDI)

Question 247

An Ethernet ____ works at the Data Link layer (layer 2) to establish separate physical network segments while keeping all nodes in the same logical network. This reduces the number of collisions caused by having too many nodes contending for access. builds a forwarding database to track which addresses are associated with which of its ports. When the bridge is initialized, the database's MAC address table is empty, but information is constantly added as the bridge listens to the connected segments.

Answer 247

bridge

Question 248

An Ethernet ______ performs the same sort of function as a bridge, but in a more granular way and for many more ports than are supported by bridges. Each ____ port is a separate collision domain.

Answer 248

switch

Question 249

Method of dividing networks to isolate workloads and the infrastructure that supports them from other workloads.In effect, the switch establishes a point to point full-duplex link between any two network nodes. This is referred to as ______

Answer 249

microsegmentation.

Question 250

Ethernet switches can be distinguished using the following general categories:

Answer 250

unmanaged vs managed stackable modular vs fixed desktop vs rack mounted

Question 251

switches are more likely to be _____, standalone units that can be added to the network and run without any configuration.

Answer 251

unmanaged

Question 252

On a corporate network, switches are most likely to be ___. This means the switch settings can be configured. If a _____ switch is left unconfigured, it functions the same as an -____ switch does.

Answer 252

managed; unmanaged

Question 253

Switches that can be connected together and operate as a group. The switch stack can be managed as a single unit.

Answer 253

Stackable

Question 254

A _____ switch comes with a set number of ports that cannot be changed or upgraded.

Answer 254

fixed

Question 255

A ______ switch has slots for plug-in cards, meaning it can be configured with different numbers and types of ports.

Answer 255

modular

Question 256

Simple unmanaged switches with five or eight ports might be supplied as small freestanding units that can be placed on a _____

Answer 256

desktop.

Question 257

Most larger switches are designed to be fitted to the standard-size racks that are used to hold networking equipment.

Answer 257

rack-mounted

Question 258

Switch Interface Configuration: This is a read-only mode where commands can be used to run basic troubleshooting tools. This mode is indicated by the > prompt.

Answer 258

User EXEC mode

Question 259

Switch Interface Configuration: This allows the user to report the configuration, show system status, reboot or shut down the appliance, and backup and restore the system configuration. This mode is activated using the enable command from user EXEC mode. It is denoted by a # prompt.

Answer 259

Privileged EXEC mode

Question 260

Switch Interface Configuration: This allows the user to write configuration updates. It is activated by using the configure terminal command from privileged mode and indicated by a (config)# prompt.

Answer 260

Global configuration mode

Question 261

What advantage does a stackable switch offer over a non-stackable -It cannot be managed as a single unit. -It offers fewer ports. -It allows for physical stacking only, without any management benefits. -It simplifies network management by allowing multiple switches to be managed as a single unit.

Answer 261

-It simplifies network management by allowing multiple switches to be managed as a single unit.

Question 262

What command is used to enter the Global Configuration mode on a Cisco switch? -enable -configure terminal -interface GigabitEthernet0/1 -do copy running-config startup-config

Answer 262

-configure terminal The configure terminal command is used to enter the Global Configuration mode from the Privileged EXEC mode. This mode allows the user to make configuration updates to the device. The enable command is used to switch from User EXEC mode to Privileged EXEC mode, not to enter Global Configuration mode.

Question 263

What is the role of the CSMA/CD protocol in a hub-based Ethernet network? -It encrypts data to prevent unauthorized access. -It assigns IP addresses to devices connected to the hub. -It manages the timing of data transmissions to avoid collisions. -It increases the data transmission speed of the hub.

Answer 263

-It manages the timing of data transmissions to avoid collisions. The Carrier Sense Multiple Access with Collision Detection (CSMA/CD) protocol is used in Ethernet networks to manage how devices on the same network segment transmit data. It allows devices to "listen" to the network to ensure no other device is transmitting (Carrier Sense). If the network is clear, a device can transmit. If two devices transmit simultaneously, a collision occurs. CSMA/CD then manages the retransmission attempts after random time delays to minimize the chance of repeated collisions. This protocol is crucial in hub-based networks, where all devices share the same collision domain.

Question 264

What distinguishes a collision domain from a broadcast domain? -Collision domains are established by routers, while broadcast domains are established by switches. -Collision domains are about physically shared media, and their borders are established by bridges and switches. -Broadcast domains require a layer 2 broadcast address to be established. -Collision domains can span multiple routers, while broadcast domains are limited to a single switch.

Answer 264

-Collision domains are about physically shared media, and their borders are established by bridges and switches.

Question 265

means combining two or more separate cabled links into a single logical channel. Combining the bandwidth of two or more switch ports into a single channel link. if one link is broken, the connection is still maintained by the other. It is also often cost-effective

Answer 265

Link aggregation

Question 266

Two or more NIC aggregated into a single channel link for fault tolerance and increased throughput. Also known as NIC bonding.

Answer 266

NIC teaming

Question 267

can be used to detect configuration errors and recover from the failure of one of the physical links. IEEE protocol governing the use of bonded Ethernet ports (NIC teaming). Also referred to as 802.3ad and 802.1ax.

Answer 267

Link Aggregation Control Protocol (LACP)

Question 268

Link aggregation is typically implemented using the IEEE _______. 802.3ad bonded interfaces are described as a link aggregation group (LAG).

Answer 268

802.3ad/802.1ax standard; 802.3ad

Question 269

A standard Ethernet frame has a maximum length of ___, excluding the preamble.

Answer 269

1,518 bytes

Question 270

Each frame has an 18-byte header:

Answer 270

6-byte destination and source MAC address fields. 4-byte error checking field. 2-byte EtherType field.

Question 271

Maximum size in bytes of a frame's payload. If the payload cannot be encapsulated within a single frame at the Data Link layer, it must be fragmented.

Answer 271

maximum transmission unit (MTU).

Question 272

The maximum size of the data payload is ______

Answer 272

1,500 bytes

Question 273

Ethernet frame with a payload larger than 1500 bytes (up to about 9000 bytes). it is critical that all hosts and appliances (switches and routers) along the communications path be able and configured to support them. support can be configured using the command mtu 9018

Answer 273

A jumbo frame

Question 274

is a means for the bridges or switches to organize themselves into a hierarchy and block loops. Protocol that prevents layer 2 network loops by dynamically blocking switch ports as needed. The switch at the top of the hierarchy is the root. The switch with the lowest ID, comprising a priority value and the MAC address, will be selected as the root.

Answer 274

The Spanning Tree Protocol (STP)

Question 275

In Spanning Tree Protocol (STP), the process and metrics that determine which bridge or switch will be identified as root. Selection of an inappropriate root device can cause performance and security issues. If a switch supports spanning tree, it should operate by default without configuration. An administrator can (and should) set the priority value to predetermine ________

Answer 275

root bridge selection.

Question 276

Blocking

Answer 276

Forwards Frames? NO Learns MACs? NO Notes - the port drops all frames other than BPDUs

Question 277

Listening

Answer 277

Forwards Frames? NO Learns MACs? NO Notes - The port is listening for BPDUs to detect loops

Question 278

Learning

Answer 278

Forwards Frames? NO Learns MACs? YES Notes - The port discovers the topology of the network and builds the MAC address table

Question 279

Forwarding

Answer 279

Forwards Frames? YES Learns MACs? YES Notes - The port works as normal

Question 280

Disabled

Answer 280

Forwards Frames? NO Learns MACs? NO Notes - The port has been disabled by the administrator

Question 281

is a means of supplying electrical power from a switch port over ordinary data cabling to a connected powered device (PD), such as a VoIP handset, IP camera, or wireless access point.

Answer 281

Power over Ethernet (PoE)

Question 282

Power is supplied as 350mA@48V and limited to 15.4 W output. Given that some of this dissipates over the length of cable, it supports PDs that require up to about 13 W.

Answer 282

3af

Question 283

Supplies at 30 W, with a maximum current of 600 mA. This can support PD requirements of up to about 25 W.

Answer 283

3at (PoE+)

Question 284

Supplies at 60 W (Type 3) or 90 W (Type 4), with up to 51 W and 71 W usable power, respectively.

Answer 284

3bt (PoE++)

Question 285

What happens when a Topology Change Notification (TCN) is received in a network using STP? -The network topology remains unchanged. -The root bridge is re-elected. -Ports may change their status from forwarding to blocked or vice versa. -All ports are set to the blocking state.

Answer 285

-Ports may change their status from forwarding to blocked or vice versa. When a TCN is received, it indicates that a device has been added or removed from the network. STP may then adjust the network topology by changing the status of ports (from forwarding to blocked or vice versa) to maintain a loop-free network.

Question 286

Which command is used to designate a switch as the primary root bridge in Spanning Tree Protocol? -spanning-tree vlan 1 root primary -spanning-tree vlan 1 set root -spanning-tree vlan 1 primary root -spanning-tree vlan 1 root set primary

Answer 286

-spanning-tree vlan 1 root primary

Question 287

What command is used to display the current Spanning Tree Protocol configuration on a Cisco switch? -show protocols spanning-tree -display spanning-tree status -show spanning-tree -view spanning-tree configuration

Answer 287

-show spanning-tree

Question 288

Which of the following is a multicast frame that contains spanning tree protocol information about switch ports that allows switches to exchange information? Bus BPDU DPs Lowest ID

Answer 288

BPDU; The spanning tree protocol (STP) information gets packaged as bridge protocol data unit (BPDU) multicast frames. Each switch then determines the shortest path to the root bridge by exchanging information with other switches.

Question 289

What happens if both sides of a link aggregation are set to passive mode? -A bonded channel is created with reduced bandwidth. -A bonded channel is created with increased latency. -No bonded channel is created. -The physical links are disabled.

Answer 289

-No bonded channel is created. When both sides of a link aggregation are set to passive mode, no bonded channel will be created because both sides are waiting for the other to initiate the LACP process. For a bonded channel to be established, at least one side must be in active mode.

Question 290

Which of the following are components of the 18-byte header in a standard Ethernet frame? (Select four.) -Payload size indicator -Destination MAC address -Preamble -Error checking field -Source MAC address -EtherType field

Answer 290

-Destination MAC address -Error checking field -Source MAC address -EtherType field

Question 291

Port Status Indicators: Solid green - Flickering green- No light - Blinking amber - solid amber-

Answer 291

Solid green—The link is connected, but there is no traffic. Flickering green—The link is operating normally (with traffic). The blink rate indicates the link speed. No light—The link is not working, or the port is shut down. Blinking amber—A fault has been detected (duplex mismatch, excessive collisions, or redundancy check errors, for instance). Solid amber—The port is blocked by the spanning tree algorithm, which works to prevent loops within a switched network.

Question 292

lists the state of all interfaces or the specified interface. An interface has a line status (up if a host is connected via a good cable) and a protocol status (up if an Ethernet link is established). will also report configuration details and traffic statistics if the link is up/up.

Answer 292

show interface

Question 293

_______ displays the switch's configuration. The startup configuration ( ____), which is configured on next boot, could be different from the running configuration ( _______). If there has been some undocumented change to the switch, using these commands and comparing the output may reveal the source of a problem.

Answer 293

show config ; show startup-config; show running-config

Question 294

If an interface is not up/up, you need to diagnose the cause from the state: down/down - Administratively down/down - Down/error disabled - Up/down (suspended) -

Answer 294

Down/down—There is no link. This is typically because no host is attached, but it could also be caused by a speed mismatch. Administratively down/down—The interface has been disabled using the shutdowncommand. Use no shutdown to bring it up. Down/error disabled—The interface is disabled due to some error state. This is typically either a spanning tree or port security violation issue. Up/down (suspended)—The port is part of a link aggregation group, and the channel has not been negotiated. Use show etherchannel to investigate the cause. Both sides should use the same speed, duplex, and link control type, and use the same number of ports. When using LACP, at least one side must be active.

Question 295

An interface might change rapidly or "flap" between up and down states, making the problem harder to observe and diagnose. Interface _______ record the number of events over time. This allows you to diagnose issues with an interface that is up but that is unreliable or performing poorly.

Answer 295

counters

Question 296

Measures whether an interface is working (up) or not (down). You would configure an alert if an interface goes down so that it can be investigated immediately. You may also want to track the uptime or downtime percentage so that you can assess a link's reliability over time.

Answer 296

Link state

Question 297

The number of times an interface has restarted over the counter period. Interfaces may be reset manually or could restart automatically if traffic volume is very high or a large number of errors are experienced. Anything but occasional resets should be closely monitored and investigated.

Answer 297

Resets

Question 298

An interface may discard incoming and/or outgoing frames for several reasons, including checksum errors, mismatched MTUs, packets that are too small (runts) or too large (giants), high load, or permissions—the sender is not on the interface's access control list (ACL) or there is some sort of virtual LAN (VLAN) configuration problem, for instance. Each interface is likely to class the type of discard or drop separately to assist with troubleshooting the precise cause.

Answer 298

Discards/drops

Question 299

______ is calculated by an interface when it sends a frame. A ___ value is calculated from the frame contents to derive a 32-bit value. This is added to the header as the frame check sequence. The receiving interface uses the same calculation. If it derives a different value, the frame is rejected. The number of ___ errors can be monitored per interface. errors are usually caused by interference.

Answer 299

A cyclic redundancy check (CRC)

Question 300

A _____ is a frame that is smaller than the minimum size (64 bytes for Ethernet). A _______ is usually caused by a collision. In a switched environment, collisions should only be experienced on an interface connected to a legacy hub device and there is a duplex mismatch in the interface configuration (or possibly on a misconfigured link to a virtualization platform). If ____ are generated in other conditions, suspect a driver issue on the transmitting host.

Answer 300

runt frame

Question 301

A _____ is a frame that is larger than the maximum permissible size (1518 bytes). There are two likely causes of giant frames:

Answer 301

giant Jumbo frames—A host might be configured to use jumbo frames, but the switch interface is not configured to receive them. This type of issue often occurs when configuring storage area networks (SANs) or links between SANs and data networks. The MTU value in the show interface output will indicate whether jumbo frames are accepted on a particular port. Ethernet trunks—A trunk link carries traffic between switches or between a switch and a router. Trunk links often use 802.1Q framing to carry virtual LAN (VLAN) information. If one switch interface is configured for 802.1Q framing, but the other is not, the frames will appear too large to the receiver, as 802.1Q adds 4 bytes to the header, making the maximum frame size 1522 bytes.

Question 302

The address mapping for that port is cached in a MAC address table. The address table is implemented as _____, a special type of memory optimized for searching, rather than random access.

Answer 302

content addressable memory (CAM); Consequently, the MAC address table is often also referred to as the CAM table.

Question 303

If a MAC address cannot be found in the MAC address table, then the switch acts like a hub and transmits the frame out of all the ports, except for the source port. This is referred to as ____

Answer 303

flooding.

Question 304

Troubleshooting issue where layer 2 frames are forwarded between switches or bridges in an endless loop.

Answer 304

A network loop

Question 305

Without intervention, this loop will continue indefinitely, causing a _____. will cause network utilization to go to near maximum capacity and the CPU utilization of the switches to jump to 80% or more. This makes the switched segment effectively unusable until the broadcast storm stops.

Answer 305

broadcast storm.

Question 306

Cabling for PoE+ must be __ or better, but standards typically recommend the use of ___

Answer 306

Cat 5e; Cat 6A.

Question 307

When configuring Power over Ethernet, the maximum amount of power available across all switchports.

Answer 307

power budget

Question 308

Fields in a datagram used to identify source and destination IP addresses, protocol type, and other layer 3 properties. contains fields to manage the logical addressing and forwarding function.

Answer 308

The Internet Protocol (IP) header

Question 309

In IPv4, the header contains

Answer 309

two fields for the 32-bit source and destination addresses, plus a number of other fields to support forwarding functions.

Question 310

indicates the version of Internet Protocol in use (4)

Answer 310

The Version field

Question 311

indicate the size of the header and the total packet size (including the payload).

Answer 311

the Length fields `

Question 312

indicate a Transmission Control Protocol (TCP/6) segment or a User Datagram Protocol (UDP/17) datagram, which work at the Transport layer. The values assigned to protocol types, such as 6 for TCP and 17 for UDP, are managed by IANA.

Answer 312

For most packets, the IP protocol type value in the Protocol field

Question 313

is used for status messaging and connectivity testing.

Answer 313

Internet Control Message Protocol (ICMP/1)

Question 314

is used with multicasting.

Answer 314

Internet Group Messaging Protocol (IGMP/2)

Question 315

is used to tunnel packets across an intermediate network. This is used (for example) in some virtual private network (VPN) implementations.

Answer 315

Generic Routing Encapsulation (GRE/47)

Question 316

are used with the encrypted form of IP (IPSec).

Answer 316

Encapsulating Security Payload (ESP/50) and Authentication Header (AH/51)

Question 317

are protocols used by routers to exchange information about paths to remote networks.

Answer 317

Enhanced Interior Gateway Routing Protocol (EIGRP/88) and Open Shortest Path First (OSPF/89)

Question 318

Forwarding at layer 3 is referred to as

Answer 318

routing

Question 319

forwarding at layer 2 is described as

Answer 319

switching.

Question 320

Broadcast mechanism by which the hardware MAC address of an interface is matched to an IP address on a local network segment.

Answer 320

the Address Resolution Protocol (ARP)

Question 321

When an IP host wants to send a packet to a single recipient, it uses a ______ packet, addressed to the IP address of the destination host.

Answer 321

unicast

Question 322

One means of addressing multiple hosts is to perform a _______. can be performed by sending a packet to the network or subnet's broadcast address.

Answer 322

broadcast; he broadcast address is the last address in any IP network or subnet.

Question 323

allows one host on the Internet (or private IP network) to send content to other hosts that have identified themselves as interested in receiving the originating host's content.

Answer 323

IP multicasting

Question 324

Multicast packets are sent to a destination IP address from a special range configured for use with that multicast group. In IPv4, ________ is reserved for multicast addressing.

Answer 324

the range 224.0.0.0 through to 239.255.255.255

Question 325

The intent to receive multicasts from a particular host is signaled by joining a multicast group. ______ is typically used to configure group memberships and IP addresses.

Answer 325

The Internet Group Management Protocol (IGMP)

Question 326

means that a group of hosts is configured with the same IP address. When a router forwards a packet to an _____ group, it uses a prioritization algorithm and metrics to select the host that is "closest" (that will receive the packet and be able to process it the most quickly). This allows the service behind the IP address to be provisioned more quickly and reliably. It allows for load balancing and failover between the server hosts sharing the IP address.

Answer 326

anycast; There isn't an anycast address range. Hosts participating in an anycast group are configured with the same unicast address. Anycast forwarding is handled by routers, typically using a dynamic routing protocol, such as Border Gateway Protocol (BGP).

Question 327

What is the function of the Protocol field in the IPv4 header? -Indicates the version of Internet Protocol in use -Specifies the type of data encapsulated in the payload -Indicates the size of the header -Specifies the total packet size

Answer 327

-Specifies the type of data encapsulated in the payload

Question 328

has three hierarchical levels: a network ID, subnet ID, and host ID. To create logical subnets, bits from the host portion of the IP address must be allocated as a subnetwork address, rather than part of the host ID. Division of a single IP network into two or more smaller broadcast domains by using longer netmasks within the boundaries of the network. Also called a subnet mask.

Answer 328

Subnet addressing

Question 329

octet mask bits: 1 2 3 4 5 6 7 8

Answer 329

Binary octet 1 = 10000000 2 = 11000000 3 = 11100000 4 = 11110000 5 = 11111000 6 = 11111100 7 = 11111110 8 = 11111111 Decimal Equivalent 1 = 128 2 = 192 3 = 224 4 = 240 5 = 248 6 = 252 7 = 254 8 = 255

Question 330

host address range for a /24 network

Answer 330

1 through 254

Question 331

host address range for a /28 network

Answer 331

1 > 14 17 > 30 33 > 46 49 > 62

Question 332

In Linux, Ethernet interfaces are classically identified as ______, and so on, although some network packages now use different schemes, such as en prefixes.

Answer 332

eth0, eth1, eth2

Question 333

What happens to the number of available host addresses when a bit is added to the subnet mask? -It doubles. -It remains the same. -It approximately halves. -It increases by a factor of four.

Answer 333

-It approximately halves. Each bit added to the subnet mask reduces the number of bits available for host addresses, approximately halving the number of available host addresses. This is because the subnet mask determines how many bits are used for the network portion versus the host portion of an IP address.

Question 334

A network administrator wants to use a subnet mask containing 62 usable addresses. Which of the following subnet masks should the administrator use? -255.255.255.192 -255.255.255.240 -255.255.255.224 -255.255.255.128

Answer 334

-255.255.255.192

Question 335

What can dynamic routing protocols allow routers to do? -Assign IP addresses dynamically. -Share information about known networks and possible paths. -Encrypt data packets for secure transmission. -Increase the speed of packet delivery.

Answer 335

-Share information about known networks and possible paths. Dynamic routing protocols enable routers to exchange information about network topologies and available routes, allowing them to dynamically adjust to changes and select optimal paths for packet forwarding.

Question 336

A host has an address of 100.55.177.99/16. Which of the following is the broadcast address for the subnet? -255.255.0.0 -255.255.255.0 -100.55.255.255 -100.255.255.255

Answer 336

-100.55.255.255 The broadcast address for the subnet is the last address on the subnet. In this example, the address uses 16 bits in the subnet mask (255.255.0.0), meaning that the first two octets indicate the subnet address (100.55.0.0), and the last two octets are used for host addresses. The last possible address on this subnet is 100.55.255.255.

Question 337

So far, we have considered IP network and subnet IDs that are defined by network masks. This is referred to as ______

Answer 337

classless addressing.

Question 338

____ scheme was employed in the 1980s, before the use of netmasks to identify the network ID portion of an address was developed. ________ allocates a network ID based on the first octet of the IP address.

Answer 338

A classful addressing

Question 339

____ network addresses support large numbers of hosts—over 16 million. However, there are only 126 _____ network addresses.

Answer 339

Class A

Question 340

There are 16,000 _____ networks, each containing up to about 65,000 hosts.

Answer 340

Class B

Question 341

_____ networks support only 254 hosts each, but there are over two million of them.

Answer 341

Class C

Question 342

First Octet: 1-126

Answer 342

Class A Class A: 255.0.0.0 (/8)

Question 343

First octet: 128-191

Answer 343

Class B Class B: 255.255.0.0 (/16)

Question 344

First octet: 192-223

Answer 344

Class C Class C: 255.255.255.0 (/24)

Question 345

is one that can establish a connection with other public IP networks and hosts over the Internet. The allocation of ______ is governed by IANA and administered by regional registries and ISPs.

Answer 345

public IP addresses

Question 346

10.0.0.0 to 10.255.255.255

Answer 346

(Class A private address range).

Question 347

172.16.0.0 to 172.31.255.255

Answer 347

(Class B private address range).

Question 348

192.168.0.0 to 192.168.255.255

Answer 348

(Class C private address range).

Question 349

Through a router configured with a single valid public IP address or a block of valid public IP addresses; the router translates between the private and public addresses using a process called ___

Answer 349

Network Address Translation (NAT)

Question 350

Through a ______that fulfills requests for Internet resources on behalf of clients. The _______ itself must be configured with a public IP address on the external-facing interface.

Answer 350

proxy server

Question 351

(224.0.0.0 through 239.255.255.255) are used for multicasting

Answer 351

Class D addresses

Question 352

(240.0.0.0 through 255.255.255.255) are reserved for experimental use and testing.

Answer 352

Class E addresses

Question 353

127.0.0.0 to 127.255.255.255 (or 127.0.0.0/8) IP address by which a host can address itself over any available interface. a special address typically used to check that TCP/IP is correctly installed on the local host.

Answer 353

loopback address

Question 354

Used when a specific address is unknown. This is typically used as a source address by a client seeking a DHCP lease.

Answer 354

0.0.0/8

Question 355

Used to broadcast to the local network when the local network address is not known.

Answer 355

255.255.255

Question 356

Set aside for a variety of special purposes.

Answer 356

64.0.0/10, 192.0.0.0/24, 192.88.99.0/24, 198.18.0.0/15

Question 357

Set aside for use in documentation and examples.

Answer 357

192.0.2.0/24, 198.51.100.0/24, 203.0.113.0/24

Question 358

The following factors must be weighed when planning an IPv4 network addressing scheme:

Answer 358

The number of IP networks and subnetworks required must be considered. The number of hosts per subnet that must be supported must be considered. The network ID must be from a valid public or a private range (not from the loopback, link local reserved range, multicast range, or reserved/experimental range, for instance). The network and/or host IDs cannot be all 1s in binary—this is reserved for broadcasts. The network and/or host ID cannot be all 0s in binary; 0 means "this network." Each host ID must be unique on the IP network or subnet. The network ID must be unique on the Internet (if you are using a public addressing scheme) or on your internal system of internetworks (if you are using a private addressing scheme).

Question 359

2^2 2^3 2^4 2^5 2^6 2^7 2^8

Answer 359

4 8 16 32 64 128 256

Question 360

1 2 3 4 5 6 7 8

Answer 360

128 192 224 240 248 252 254 255

Question 361

Using network prefixes to aggregate routes to multiple network blocks ("supernetting"). This replaced the old method of assigning class-based IP addresses based on the network size. uses bits normally assigned to the network ID to mask the complexity of the subnet and host addressing scheme within that network.

Answer 361

Classless Inter-Domain Routing (CIDR)

Question 362

A complementary classless addressing technique, called _____ allows a network designer to allocate ranges of IP addresses to subnets that match the predicted need for numbers of subnets and hosts per subnet more closely. allows different length netmasks to be used within the same IP network, allowing more flexibility in the design process.

Answer 362

variable length subnet masking (VLSM),

Question 363

Why is VLSM considered a complementary technique to supernetting? -Because it allows for the allocation of IP addresses to ISPs -Because it simplifies network design -Because it allows for more efficient IP address allocation -Because it increases the IPv4 address space

Answer 363

-Because it allows for more efficient IP address allocation VLSM complements supernetting by allowing for more efficient allocation of IP addresses within a network. While supernetting aggregates multiple IP networks into a larger one to simplify routing, VLSM provides the flexibility to allocate IP address ranges to subnets based on actual needs, reducing wastage.

Question 364

What is the main advantage of using VLSM over traditional fixed-length subnet masking? -It simplifies the routing table. -It allows for the use of the same subnet mask throughout the network. -It reduces the number of wasted IP addresses. -It increases the total number of available IP addresses.

Answer 364

-It reduces the number of wasted IP addresses. The main advantage of VLSM is its ability to reduce IP address wastage by allowing subnets of different sizes within the same network. This flexibility ensures that each subnet gets just the right amount of IP addresses, minimizing unused addresses.

Question 365

Which of the following IP address ranges or IP addresses is specifically set aside for use in documentation and examples? -172.16.0.0/12 -192.0.2.0/24 -224.0.0.0 through 239.255.255.255 -127.0.0.0 to 127.255.255.255

Answer 365

-192.0.2.0/24 The IP address range 192.0.2.0/24 is specifically reserved for use in documentation and examples. This helps avoid confusion and potential conflicts by ensuring that the examples provided in documentation do not accidentally correspond to real IP addresses in use on the Internet or within private networks. 224.0.0.0 through 239.255.255.255 is the IP address range reserved for multicasting, not for documentation and examples.127.0.0.0 to 127.255.255.255 is reserved for loopback addresses, which are used for internal testing and communication within the host, not for documentation and examples.

Question 366

When subnetting the network address 172.30.0.0/16 to support 12 subnets, what is the new subnet mask in dotted decimal format? -255.255.255.0 -255.255.240.0 -255.255.248.0 -255.255.0.0

Answer 366

-255.255.240.0 To support 12 subnets, you round up to the nearest power of 2, which is 16. This requires 4 bits (2^4 = 16). Adding 4 bits to the default /16 mask results in a /20 mask, which in dotted decimal format is 255.255.240.0. 11110000 Here’s how that becomes 240: Each position has a value: 128 64 32 16 8 4 2 1 1 1 1 1 0 0 0 0 Add the 1s: 128 + 64 + 32 + 16 = 240 That’s where 240 comes from 🎯

Question 367

77.8.5 130.0.9 190.250.10 220.89.44 Which of the following represents (in order) the IP address class of each listed IP address? -Class A, Class B, Class B, Class C -Class B, Class B, Class C, Class C -Class A, Class B, Class C, Class C -Class B, Class B, Class C, Class D -Class B, Class C, Class C, Class D

Answer 367

-Class A, Class B, Class B, Class C 1-126 = Class A 128-191 = Class B 192-223 = Class C 224-239 = Class D 240-255 = Class E

Question 368

Which of the following IP addresses are Class C addresses? (Select two.) -192.15.5.55 -189.189.5.2 -223.16.5.0 -240.0.0.0 -125.166.11.0

Answer 368

-192.15.5.55 -223.16.5.0

Question 369

How do routers external to the network utilize CIDR? -By using the /22 prefix to simplify routing and reduce the complexity of their routing tables -By encrypting data packets based on the CIDR notation -By assigning dynamic IP addresses to devices within the network -By directly managing the LAN's internal subnet configurations

Answer 369

-By using the /22 prefix to simplify routing and reduce the complexity of their routing tablesRouters external to the network use the /22 prefix (or other summarized prefixes provided by CIDR) to simplify routing. This approach allows these routers to treat multiple IP addresses as part of a single, larger network, thereby reducing the number of entries in their routing tables and simplifying the routing process. This is a key advantage of CIDR, as it helps in managing the scalability of Internet routing by reducing the overall complexity.

Question 370

without any switches will display the IP address, subnet mask, and default gateway (router) for all network interfaces to which TCP/IP is bound.

Answer 370

ipconfig

Question 371

displays complete TCP/IP configuration parameters for each interface, including whether the Dynamic Host Configuration Protocol (DHCP) is enabled for the interface and the interface's hardware (MAC) address.

Answer 371

ipconfig /all

Question 372

forces a DHCP client to renew the lease it has for an IP address.

Answer 372

ipconfig /renew interface

Question 373

releases the IP address obtained from a DHCP server so that the interface(s) will no longer have an IP address.

Answer 373

ipconfig /release interface

Question 374

displays the Domain Name System (DNS) resolver cache.

Answer 374

ipconfig /displaydns

Question 375

clears the DNS resolver cache.

Answer 375

ipconfig /flushdns

Question 376

registers the host with a DNS server (if it supports dynamic updates).

Answer 376

ipconfig /registerdns

Question 377

command is used to enable or disable an interface

Answer 377

The ip link set eth0 up|down

Question 378

can be used to modify the IP address configuration

Answer 378

ip addr add|delete

Question 379

is used by hosts to determine which MAC address is associated with an IP address on the local network. are sent as broadcasts. can generate considerable traffic on a network, which can reduce performance.

Answer 379

The Address Resolution Protocol (ARP)

Question 380

can be used to perform functions related to the ARP table cache. You would use this to diagnose a suspected problem with local addressing and packet delivery.

Answer 380

The arp command

Question 381

shows the ARP cache contents. You can use this with IPAddress to view the ARP cache for the specified interface only. The ARP cache will not necessarily contain the MAC addresses of every host on the local segment. There will be no cache entry if there has not been a recent exchange of frames.

Answer 381

arp -a (or arp -g

Question 382

adds an entry to the ARP cache. Under Windows, MACAddress needs to be entered with hyphens between each hex byte.

Answer 382

arp -s IPAddress MACAddress

Question 383

deletes all entries in the ARP cache; it can also be used with IPAddress to delete a single entry.

Answer 383

arp -d *

Question 384

command shows entries in the local ARP cache (replacing the old arp command).

Answer 384

In Linux, the ip neigh

Question 385

is used to report errors and send messages about the delivery of a packet. are generated under error conditions in most types of unicast traffic but not for broadcast or multicast packets. can also be used to test and troubleshoot connectivity issues on IP networks.

Answer 385

The Internet Control Message Protocol (ICMP)

Question 386

IP header field is reduced by one every time a packet is forwarded by a router (referred to as a hop). output field in the ping command shows the value of the counter when the packet arrived at its destination.

Answer 386

The Time to Live (TTL) IP header

Question 387

There is no routing information (that is, the local computer does not know how to get to that IP address). This might be caused by some sort of configuration error on the local host, such as an incorrect default gateway, by a loss of connectivity with a router, or by a routing configuration error.

Answer 387

ping Error Messaging - Destination host unreachable

Question 388

The host is unavailable or cannot route a reply to your computer. Requests time out when the TTL is reduced to 0 because the packet is looping (because of a corrupted routing table), when congestion causes delays, or when a host does not respond.

Answer 388

ping Error Messaging - No reply (Request Timed Out.)

Question 389

You are troubleshooting a connectivity problem on a Linux server. You're able to connect to another system on the local network but not to a server on a remote network. You suspect that the default gateway information for the system may be configured incorrectly. Which of the following would you use to view the default gateway information on the Linux server? -ipconfig -Telnet -route -dig

Answer 389

-route Use the route command on systems running Linux to view information on the TCP/IP configuration, including the default gateway.

Question 390

What is the purpose of the ip -s link command? -To add or delete IP addresses -To enable or disable interfaces -To report interface statistics -To configure firewall rules

Answer 390

-To report interface statistics The ip -s link command is used to report interface statistics, such as the number of packets transmitted and received. The -s option stands for statistics, providing detailed information about network interface performance.

Question 391

consists of two or three elements: the main header, which is a fixed length (unlike in IPv4), one or more optional extension headers, and the payload.

Answer 391

An IPv6 packet

Question 392

ipv6 - Describes the packet’s priority.

Answer 392

Traffic Class

Question 393

ipv6 - Used for quality of service (QoS) management, such as for real-time streams. This is set to 0 for packets not part of any delivery sequence or structure.

Answer 393

Flow Label

Question 394

ipv6 - Indicates the length of the packet payload, up to a maximum of 64 KB; if the payload is bigger than that, this field is 0, and a special Jumbo Payload (4 GB) option is established.

Answer 394

Payload Length

Question 395

ipv6 - Used to describe what the next extension header (if any) is, or where the actual payload begins.

Answer 395

Next Header

Question 396

ipv6 - Replaces the TTL field in IPv4 but performs the same function.

Answer 396

Hop Limit

Question 397

ipv6 - replace the Options field in IPv4

Answer 397

Extension headers; There are several predefined extension headers to cover functions such as fragmentation and reassembly, security (IPSec), source routing, and so on.

Question 398

An IPv6 address is divided into two parts:

Answer 398

the first 64 bits are used as a network ID, while the second 64 bits designate a specific interface

Question 399

IPv6 unicast addressing is _____; a ____ is a region of the network.

Answer 399

scope

Question 400

______ provide the equivalent of public addressing schemes in IPv4, while link local schemes provide private addressing.

Answer 400

Global scopes

Question 401

The parts of a global address are as follows:

Answer 401

The first 3 bits (001) indicate that the address is within the global scope. Most of the IPv6 address space is unused. The scope for globally unique unicast addressing occupies just 1/8th of the total address space. In hex, globally scoped unicast addresses will start with a 2 (0010 in binary) or 3 (0011). The next 45 bits are allocated in a hierarchical manner to regional registries and from them to ISPs and end users. The next 16 bits identify site-specific subnet addresses. The final 64 bits are the interface ID.

Question 402

The 64-bit interface ID can be determined by using two techniques.

Answer 402

One is by using the interface's MAC address. In the second technique, referred to as privacy extensions, the client device uses a pseudorandom number for the interface ID.

Question 403

As a MAC address is 48 bits, a translation mechanism allows driver software to create a 64-bit interface ID from these 48 bits. Formally, this is called an Extended Unique Identifier-64 (EUI-64). First, the digits fffe are added in the middle of the MAC address. Second, the first 8 bits, or 2 hex digits, are converted to binary, and the 7th bit (or U/L bit) is flipped (from 0 to 1 or 1 to 0).

Answer 403

One is by using the interface's MAC address. This is known as a MAC-derived address or interface identifier.

Question 404

This is known as a temporary interface ID or token. There is some concern that using interface identifiers would allow a host to be identified and closely monitored when connecting to the Internet, and using a token mitigates this to some degree.

Answer 404

In the second technique, referred to as privacy extensions, the client device uses a pseudorandom number for the interface ID.

Question 405

addresses span a single subnet (they are not forwarded by routers). IP addressing scheme used within the scope of a single broadcast domain only. start with a leading fe80, with the next 54 bits set to 0, and the last 64 bits are the interface ID.

Answer 405

Link local addresses

Question 406

Parameter assigned by a host to distinguish ambiguous interface addresses within a link local scope. A link local address is also appended with a

Answer 406

zone index (or scope id) of the form %1 (Windows) or %eth0 (Linux).

Question 407

The parts of a multicast address are subdivided as follows:

Answer 407

The first 8 bits indicate that the address is within the multicast scope (1111 1111 or ff). The next 4 bits are used to flag types of multicast if necessary; otherwise, they are set to 0. The next 4 bits determine the scope; for example, 1 is node-local (to all interfaces on the same node), and 2 is link local. The final 112 bits define multicast groups within that scope.

Question 408

allows nodes to join a multicast group and discover whether members of a group are present on a local subnet.

Answer 408

The Multicast Listener Discovery (MLD) protocol

Question 409

Broadcast addresses are not implemented in IPv6. Instead, hosts use an appropriate

Answer 409

multicast address for a given situation.

Question 410

IPv6 replaces ARP with the ____; used to identify link local nodes.

Answer 410

Neighbor Discovery (ND) Protocol.

Question 411

Each unicast address for an interface is configured with a corresponding solicited-node multicast address.

Answer 411

It has the prefix ff02::1:ff plus the last 24 bits of the unicast address.

Question 412

hosts and routers can run both IPv4 and IPv6 simultaneously and communicate with devices configured with either type of address.

Answer 412

Dual stack

Question 413

can be used to deliver IPv6 packets across an IPv4 network. means that IPv6 packets are inserted into IPv4 packets and routed over the IPv4 network to their destination. Routing decisions are based on the IPv4 address until the packets approach their destinations, at which point the IPv6 packets are stripped from their IPv4 carrier packets and forwarded according to IPv6 routing rules.

Answer 413

Tunneling

Question 414

allows a wide variety of Network layer protocols to be encapsulated inside virtual point-to-point links. This protocol has the advantage that because it was originally designed for IPv4, it is considered a mature mechanism and can carry both v4 and v6 packets over an IPv4 network.

Answer 414

Another option for tunneling is Generic Routing Encapsulation (GRE)

Question 415

This is a well-known process for rewriting network addresses as they pass routing boundaries. With _____, an IPv6 host addresses an IPv4 host using the prefix 64:ff9b::/96 plus the 32-bit IPv4 destination address. When the packet reaches the gateway router, it strips the prefix and forwards the packet using IPv4 headers. Replies from the IPv4 host are directed to the IPv6 host by tracking connections using Transport layer port numbers.

Answer 415

Network Address Translation (NAT); NAT64

Question 416

Prefix - 2000::/3 Leading Hex characters - 2, 3

Answer 416

Global unicast

Question 417

prefix - fe80::/10 Leading Hex characters - fe80

Answer 417

Link local unicast

Question 418

Prefix - ff00::/8 Leading hex characters - ff

Answer 418

Multicast

Question 419

prefix - ff02::/16 Leading hex characters - ff02::1 (all nodes), ff02::2 (all routers), ff02::1:2 (DHCP)

Answer 419

multicast (link local)

Question 420

prefix - ff02::1:ff00:0/104 leading hex characters - ff02::1:ff

Answer 420

solicited-node

Question 421

prefix - ::/128 leading hex characters - 0::0

Answer 421

unspecified

Question 422

prefix - ::1/128 leading hex characters - ::1

Answer 422

Loopback

Question 423

prefix - 2001:db8::/32 leading hex characters - 2001:db8

Answer 423

Documentation/examples

Question 424

Globally unique unicast addresses are also widely referred to as __

Answer 424

/48s.

Question 425

A host that has not obtained a valid address. This is often expressed as ::.

Answer 425

Unspecified address (0:0:0:0:0:0:0:0)

Question 426

Used for testing (for the host to send a packet to itself). This is often expressed as ::1.

Answer 426

Loopback address (0:0:0:0:0:0:0:1)

Question 427

Which of the following is true about the scope of IPv6 global unicast addresses? -They are equivalent to private IPv4 addresses. -They are not routable over the Internet. -They occupy 1/8th of the total IPv6 address space. -They are primarily used for broadcasting messages.

Answer 427

-They occupy 1/8th of the total IPv6 address space. IPv6 global unicast addresses are designed to be routable over the Internet and are equivalent to public IPv4 addresses. They occupy a relatively small portion of the total IPv6 address space, specifically 1/8th, indicating a vast amount of available addresses.

Question 428

What does flipping the 7th bit of the first octet in a MAC address to form an EUI-64 address accomplish? -It indicates that the address is multicast. -It signifies that the address is now private. -It differentiates the modified address from the original MAC address. -It converts the address to a link-local address.

Answer 428

-It differentiates the modified address from the original MAC address.

Question 429

What prefix do 6to4 addresses use? -64:ff9b::/96 -2002::/16 -3544::/16 -6RD::/16

Answer 429

-2002::/16 6to4 automatic tunneling uses the prefix 2002::/16 for its addresses. This method allows IPv6 packets to be sent over an IPv4 network without any host configuration necessary to enable the tunnel

Question 430

What does the classless notation "/64" signify in an IPv6 network address? -The address is divided into 64 subnets. -The first 64 bits are reserved for the network prefix. -The first 64 bits specify the portion of 64 bits are the global routing prefix. -The last 64 bits are used for multicast addressing.

Answer 430

-The first 64 bits are reserved for the network prefix.

Question 431

What do the first 8 bits of an IPv6 multicast address indicate? -The address is within the unicast scope. -The address is within the multicast scope. -The address is reserved for anycast addressing. -The address is used for Neighbor Discovery protocol.

Answer 431

-The address is within the multicast scope.

Question 432

How does IPv6 anycast addressing differ from multicast addressing? -Anycast uses a single address for multiple interfaces globally. -Anycast allows a packet to be sent from multiple sources to a single interface. -Multicast sends a packet from a single source to a single interface. -Multicast uses a special range of addresses for routing protocols

Answer 432

-Anycast uses a single address for multiple interfaces globally.

Question 433

What is the role of a zone index in IPv6 link local addressing? -To encrypt the address -To provide global routing information -To make the address unique to a particular link -To increase the address space:

Answer 433

-To make the address unique to a particular link; The zone index is used to distinguish between different links or interfaces on a single device, ensuring that the link local address is unique to each network interface.

Question 434

What is the primary purpose of IPv6 link local addresses? -To provide global internet connectivity -To enable communication within a single subnet without the need for a router -To assign addresses for email servers -To encrypt data packets for secure communication

Answer 434

-To enable communication within a single subnet without the need for a router

Question 435

Which of the following statements correctly describes the use of canonical notation in IPv6 addresses? -Canonical notation allows multiple contiguous series of zeros in an IPv6 address to be replaced by double colons (::). -Canonical notation permits the removal of all zeros in an IPv6 address, regardless of their position. -Canonical notation allows leading zeros in each 16-bit block of an IPv6 address to be ignored, and one contiguous series of zeros to be replaced by a double colon (::). -Canonical notation requires that all zeros in an IPv6 address be explicitly represented, without any compression.

Answer 435

-Canonical notation allows leading zeros in each 16-bit block of an IPv6 address to be ignored, and one contiguous series of zeros to be replaced by a double colon (::).

Question 436

What is the prefix notation for globally unique unicast IPv6 addresses commonly referred to as? -/32 -/48 -/64 -/128

Answer 436

-/48 Globally unique unicast addresses in IPv6 are widely referred to as /48s. This notation indicates that the first 48 bits of the address are used for network identification, leaving the remaining bits for interface identification. This allows for a large number of unique addresses within a single network. The /32 prefix is typically used for IPv4 addresses and is not commonly associated with IPv6 globally unique unicast addresses. While /64 is a common subnet size for local networks in IPv6, it is not the prefix notation specifically used to refer to globally unique unicast addresses. The /128 prefix indicates a single IPv6 address, not a range of addresses, and is therefore not correct for globally unique unicast addresses.

Question 437

If the address configuration on the local host seems to be correct, you can complete a series of connectivity tests using ping to determine the likely location and scope of a fault.

Answer 437

Ping the loopback address ( ping 127.0.0.1) to verify TCP/IP is installed and loaded correctly. If this fails, reinstall the network protocol stack. Ping the IP address of the local host to verify it was added correctly and to verify that the network adapter is functioning properly. If you cannot ping the host's own address, there might have been a configuration error, or the network adapter or adapter driver could be faulty. Ping the IP address of the default gateway to verify it is up and running and that you can communicate with another host on the local network. Ping the IP address of other hosts on the same subnet to test for local configuration or link problems. If a local host cannot be pinged and the error is destination unreachable, then verify the IP configuration does not contain an incorrect IP address or netmask. If these are correct but pings still time out, suspect either a security issue (such as a switch port security issue) or a problem at the Data Link or Physical layer. Ping the IP address of a remote host to verify you can communicate through the router. If a remote IP address cannot be contacted, check the default gateway parameter on the local host to rule out an incorrect default gateway issue. If the gateway is configured correctly and you can ping the router, you need to start investigating the routing infrastructure.

Question 438

The following main parameters define a routing entry:

Answer 438

Protocol Destination Interface Gateway/next hop

Question 439

The source of the route. Paths can be configured statically or learned by exchanging information with other routers via a dynamic routing protocol.

Answer 439

Protocol

Question 440

Routes can be defined to specific hosts but are more generally directed to network IDs. The most specific (longest) destination prefix will be selected as the forwarding path if there is more than one match.

Answer 440

Destination

Question 441

The local interface to use to forward a packet along the chosen route. This might be represented as the IP address of the interface or as a layer 2 interface ID.

Answer 441

Interface

Question 442

The IP address of the next router along the path to the destination.

Answer 442

Gateway/next hop

Question 443

Routing table entries fall into four general categories:

Answer 443

Directly connected routes Remote routes Host routes Default route

Question 444

For subnets for which the router has a local interface. The IP network or subnet for each active router interface is automatically added to the routing table. These are known as

Answer 444

Directly connected routes

Question 445

For subnets and IP networks that are not directly attached.

Answer 445

Remote routes

Question 446

To a specific IP address. A host route has a /32 (IPv4) or /128 (IPv6) prefix.

Answer 446

Host routes

Question 447

To use when an exact match for a network or host route is not found. Entry in the routing table to represent the fowarding path that will be used if no other entries are matched.

Answer 447

Default route

Question 448

_______ is manually added to the routing table and only changes if edited by the administrator. Configuring static routing entries can be useful in some circumstances, but it can be problematic if the routing topology changes often, as each route on each affected router needs to be updated manually. can be configured either as non-persistent or persistent/permanent. is a special type of static route that identifies the next hop router for a destination that cannot be matched by another routing table entry. The destination address 0.0.0.0/0 (IPv4) or ::/0 (IPv6) is used to represent the

Answer 448

A static route; The default route is also described as the gateway of last resort.

Question 449

route is removed from the routing table if the router is rebooted.

Answer 449

. A non-persistent

Question 450

the router uses ARP (IPv4) or Neighbor Discovery (ND in IPv6) to determine the Data Link layer address of the destination interface.

Answer 450

If the packet can be delivered to a directly connected network via an Ethernet interface

Question 451

it inserts the next hop router's MAC address as the destination address in a new frame and uses the MAC address of the outgoing interface as the source address.

Answer 451

If the packet can be forwarded via a gateway over an Ethernet interface

Question 452

the router encapsulates the packet in an appropriate frame type.

Answer 452

If the packet can be forwarded via a gateway over another type of interface (leased line or DSL, for instance),

Question 453

the packet is either forwarded via the default route or dropped (and the source host is notified that it was undeliverable).

Answer 453

If the destination address cannot be matched to a route entry,

Question 454

At each router, the ____ header field is decreased by at least 1. This could be greater if the router is congested. The ___ is nominally the number of seconds a packet can stay on the network before being discarded. While ___ is defined as a unit of time (seconds), in practice, it is interpreted as a maximum hop count. When the ___ is 0, the packet is discarded. This prevents badly addressed packets from permanently circulating the network.

Answer 454

Time to Live (TTL)

Question 455

Mechanism for splitting a layer 3 datagram between multiple frames to fit the maximum transmission unit (MTU) of the underlying Data Link network.

Answer 455

IP fragmentation.

Question 456

will output the active routing table. As well as destination, gateway, AD/metric, and interface, the output will show the source of the route, identified as a letter code (C = connected, S = static, R = RIP, B = BGP, D = EIGRP, O = OSPF, and so on). Command tools used in router operating systems to list the contents of routing tables.

Answer 456

The show route, show ip route, show ipv6 route, or similar show route command

Question 457

As with any IP host, a router keeps a cache of IP addresses that have been resolved to MAC addresses via the Address Resolution Protocol (ARP). Inspecting the ARP cache table is useful for discovering duplicate IP addresses, IP misconfigurations, and routing protocol misconfigurations. To view the cache, use

Answer 457

show arp or show ip arp.

Question 458

is used to view and modify the routing table of end system Windows and Linux hosts. Cross-platform command tools used display and manage the routing table on a Windows or Linux host.

Answer 458

The route command

Question 459

tool allows you to test the whole path between two nodes with a view to isolating the node or link that is causing the problem. Diagnostic utilities that trace the route taken by a packet as it "hops" to the destination host on a remote network. tracert is the Windows implementation, while traceroute runs on Linux.

Answer 459

The traceroute

Question 460

What is the default probe message type used by the tracert command on Windows systems? -ICMP Echo Request -TCP SYN -UDP -ARP Request

Answer 460

The tracert command on Windows systems uses ICMP Echo Request probes by default to trace the path to a target host. This method helps in identifying the route and diagnosing any issues along the path.

Question 461

Which command outputs the active routing table and includes details such as destination, gateway, and the source of the route? -show route -route print -ip route show -show arp

Answer 461

-show route The show route command is used on routers to output the active routing table, including comprehensive details such as destination, gateway, AD/metric, interface, and the source of the route, identified by letter codes. The show route command is used on routers to output the active routing table, including comprehensive details such as destination, gateway, AD/metric, interface, and the source of the route, identified by letter codes. The route print command is specific to Windows hosts and, while it does show the routing table, it is not the command that provides the detailed output described, especially regarding the source of the route. The ip route show Linux command displays the routing table but the question specifically describes the output format typical of router commands like show route. The show arp command is used to view the ARP cache, not the routing table, and does not provide information on destinations, gateways, or route sources.

Question 462

What does the Time to Live (TTL) header field represent in a packet? -The maximum number of routers the packet can pass through -The maximum distance the packet can travel -The maximum time the packet can exist on the network -The priority assigned to the packet for data transmission

Answer 462

-The maximum number of routers the packet can pass through

Question 463

How does IPv6 handle packet fragmentation differently from IPv4? -IPv6 allows routers to perform fragmentation. -IPv6 requires the host to perform path MTU discovery. -IPv6 increases the MTU to avoid fragmentation. -IPv6 uses a different header field for fragmentation management.

Answer 463

-IPv6 requires the host to perform path MTU discovery.

Question 464

uses an algorithm and metrics to build and maintain a routing information base. Entry in the routing table that has been learned from another router via a ________. Also called a learned route.

Answer 464

A dynamic routing protocol

Question 465

______ is one that was communicated to a router by another router. A router can add _____ from one or more routing protocols to its IP routing table.

Answer 465

A learned route

Question 466

Most algorithms are classed as either ______. Some protocols use a hybrid of different methods to perform path selection more efficiently.

Answer 466

distance vector or as link state

Question 467

Algorithm used by routing protocols that select a forwarding path based on the next hop router with the lowest hop count to the destination network.

Answer 467

distance vector

Question 468

Algorithm used by routing protocols that build a complete network topology to use to select optimum forwarding paths.

Answer 468

link state

Question 469

is the process whereby routers running dynamic routing algorithms agree on the network topology. Routers must be capable of adapting to changes such as newly added networks, router or router interface failures, link failures, and so on. Process whereby routers agree on routes through the network to establish the same network topology in their routing tables (steady state). The time taken to reach steady state is a measure of a routing protocol's convergence performance.

Answer 469

Convergence

Question 470

_______ means that a packet is discarded without notification back to the source; a loop causes a packet to be forwarded around the network until its TTL expires.

Answer 470

A sinkhole

Question 471

A network where all the routers share the same topology is described as ______

Answer 471

steady state

Question 472

A network under the administrative control of a single owner is referred to as an __

Answer 472

autonomous system (AS).

Question 473

_____ is one that identifies routes within an AS.

Answer 473

An Interior Gateway Protocol (IGP)

Question 474

___________is one that can advertise routes between autonomous systems. includes a field to communicate the network's autonomous system ID and allows network owners to determine whether they can use paths through another organization's network.

Answer 474

An Exterior Gateway Protocol (EGP)

Question 475

is a distance vector routing protocol. only considers a single piece of information about the network topology—the next hop router to reach a given network or subnet (vector). It considers only one metric to select the optimal path to a given destination network—the one with the lowest hop count (distance). is no longer widely deployed, it is useful to review how it works to help to understand the function of more advanced and widely used protocols.

Answer 475

The Routing Information Protocol (RIP)

Question 476

________ was developed by Cisco to provide a routing protocol for routing within a domain or autonomous system.

Answer 476

The Interior Gateway Routing Protocol (IGRP)

Question 477

Limitations in IGRP, such as lack of support for classless addressing, led to the development of _______. is a distance vector protocol because it relies on neighboring routers to report paths to remote networks. Unlike RIP, which is based on a simple hop count metric, ____ uses a metric composed of administrator weighted elements. The two default elements are bandwidth and delay. maintains a topology table alongside its routing information base. is a default IP protocol, which means that it is encapsulated directly in IP datagrams, rather than using TCP or UDP. also uses hello messaging, which confirms connectivity with its neighbors. It is also tagged with the protocol number 88 in the Protocol field of the IP header. Updates are transmitted using multicast addressing.

Answer 477

Enhanced IGRP (EIGRP)

Question 478

Applies a cost based on the lowest bandwidth link in the path.

Answer 478

Bandwidth

Question 479

Applies a cost based on the time it takes for a packet to traverse the link. This metric is most important if the route is used to carry time-sensitive data, such as voice or video. Delay is calculated as the cumulative value for all outgoing interfaces in the path.

Answer 479

Delay

Question 480

Dynamic routing protocol that uses a link-state algorithm and a hierarchical topology. is suited to large organizations with multiple redundant paths between networks. is hierarchical.

Answer 480

Open Shortest Path First (OSPF)

Question 481

is designed to be used between routing domains in a mesh internetwork and as such is used as the routing protocol on the Internet, primarily between ISPs. Path vector exterior gateway routing protocol used principally by ISPs to establish routing between autonomous systems. works over TCP on port 179.

Answer 481

The Border Gateway Protocol (BGP)

Question 482

If a router has multiple entries to similar networks in its routing table, it must determine which route to prefer. The first determining factor is that _____ are preferred over shorter ones. This is referred to as _____

Answer 482

longer prefixes; longest prefix match.

Question 483

Metric determining the trustworthiness of routes derived from different routing protocols. is used to express the relative trustworthiness of the protocol supplying the route.are coded into the router but can be adjusted by the administrator if necessary.

Answer 483

administrative distance (AD) value. Local interface/Directly connected - 0 Static route - 1 BGP - 20 EIGRP - 90 OSPF - 110 RIP - 120 Unknown - 255

Question 484

What can cause convergence problems in a dynamic routing network? -A stable network with no changes -A flapping interface -Consistent routing information across all routers -The use of static routing protocols

Answer 484

-A flapping interface; A flapping interface, which frequently changes its state from up to down and back again, can cause convergence problems. This is because each state change can trigger the routers to recalculate routes, leading to instability and inconsistent routing information across the network.

Question 485

If a router has two routes to the same destination with identical prefix lengths, within the same routing protocol, how does it choose which route to use? -By selecting the route with the largest packet size -By choosing the route with the lowest metric -By preferring the route with the shortest prefix -By using the Administrative Distance (AD) value

Answer 485

-By choosing the route with the lowest metric

Question 486

______ placed at the network perimeter, are typified by distinguishing external (Internet-facing) and internal interfaces. can perform framing to repackage data from the private LAN frame format to the WAN Internet access frame format.

Answer 486

Edge routers,

Question 487

The customer's router is referred to as _______

Answer 487

the customer edge (CE)

Question 488

the service provider's router is referred to as _____

Answer 488

the provider edge (PE).

Question 489

is primarily deployed as a service translating between a private (or local) addressing scheme used by hosts on the LAN and a public (or global) addressing scheme used by an Internet-facing device. Routing mechanism that conceals internal addressing schemes from the public Internet by translating between a single public address on the external side of a router and private, non-routable addresses internally.

Answer 489

Network Address Translation (NAT)

Question 490

Maps private host IP addresses onto a single public IP address. Each host is tracked by assigning it a random high TCP port for communications.

Answer 490

Port Address Translation (PAT); This can be referred to as Network Address Port Translation (NAPT), NAT overloading, one-to-many NAT, many-to-one NAT, or NAT masquerade.

Question 491

Which of the following problems does NAT help address? -The shortage of IPv4 addresses -Registering IP addresses with an ISP -The shortage of IPv6 addresses -IPsec not working properly

Answer 491

-The shortage of IPv4 addresses

Question 492

The basic function of a firewall is _____. The firewall processes traffic according to rules. Traffic that does not conform to a rule is blocked.

Answer 492

traffic filtering.

Question 493

_____ is configured by specifying rules in a network access control list (ACL). Each rule defines a specific type of data packet and the appropriate action to take when a packet matches the rule. An action can be either to deny (block or drop the packet, and optionally log an event) or to accept (let the packet pass through the firewall). works at layer 3 of the OSI model to inspect the headers of IP packets.

Answer 493

A packet filtering firewall

Question 494

Accepting or denying traffic based on its source and/or destination IP address.

Answer 494

IP Filtering

Question 495

Accepting or denying a packet based on source and destination Transport layer port numbers.

Answer 495

Port Filtering/Security

Question 496

This means that rules can be based on the information found in those headers:

Answer 496

IP filtering Protocol ID/type (TCP, UDP, ICMP, routing protocols, and so on). Port filtering/security

Question 497

This means that it does not preserve information about the connection between two hosts. Each packet is analyzed independently with no record of previously processed packets. This type of filtering requires the least processing effort, but it can be vulnerable to attacks that are spread over a sequence of packets

Answer 497

A packet filtering firewall is stateless.

Question 498

addresses these problems by maintaining stateful information about the session established between two hosts (including malicious attempts to start a bogus session). Information about each session is stored in a dynamically updated state table. operates at layer 5 (Session) of the OSI model. When a packet arrives, the firewall checks it to confirm whether it belongs to an existing connection. If it does not, it applies the ordinary packet filtering rules to determine whether to allow it.

Answer 498

A circuit-level stateful inspection firewall

Question 499

is a stand-alone hardware firewall that performs only the function of a firewall.The functions of the firewall are implemented on the appliance firmware. This is also a type of network-based firewall and monitors all traffic passing into and out of a network segment.

Answer 499

An appliance firewall

Question 500

similar to an appliance firewall; the functionality is built into the router firmware.

Answer 500

A router firewall

Question 501

establishes how nodes are physically and logically connected. Recall that the basic topologies are as follows: point-to-point, star, mesh

Answer 501

network topology

Question 502

is anything that uses a mixture of point-to-point, star, and mesh physical and/or logical topologies. often used to implement redundancy and fault tolerance or to connect sites in WANs and in enterprise campus networks:

Answer 502

A hybrid topology

Question 503

Corporate networks are often designed in a hierarchy, also known as a tree topology. This can be combined with a star topology to implement each node in the overall tree. The links between nodes in the tree are referred to as backbones or trunks because they aggregate and distribute traffic from multiple different areas of the network.

Answer 503

Hierarchical star

Question 504

Alternatively, nodes at the top of the hierarchy can be configured in a partial or full mesh for redundancy. Switches or routers lower in the hierarchy establish star topologies that connect end systems to the network.

Answer 504

Hierarchical Star-mesh

Question 505

A WAN might be configured as a hub and spoke between a central office and branch offices, with each site implementing a star topology to connect end systems. This is also referred to as a snowflake topology.

Answer 505

Star of stars

Question 506

Paradigm to simplify network design by separating switch and router functionality and placement into three tiers each with a separate role, performance requirements, and physical topology. access, distribution, and core.

Answer 506

three-tiered hierarchy

Question 507

allows end user devices, such as computers, printers, and smartphones to connect to the network. is implemented for each site using structured cabling and wall ports for wired access and access points for wireless access. Lowest tier in a hierarchical network topology acting as the attachment point for end systems.

Answer 507

Access/Edge Layer

Question 508

provides fault-tolerant interconnections between different access blocks and either the core or other distribution blocks. Intermediate tier in a hierarchical network topology providing interconnections between the access layer and the core. often used to implement traffic policies, such as routing boundaries, filtering, or quality of service (QoS).

Answer 508

The distribution or aggregation layer

Question 509

Switch appliance capable of IP routing between virtual LAN (VLAN) subnets using hardware-optimized path selection and forwarding. used to implement the distribution/aggregation layer have different capabilities to the layer 2 workgroup switches used in the access tier.

Answer 509

The layer 3 capable switches

Question 510

While a router uses a generic processor and firmware to process incoming packets, a layer 3 switch uses an ______

Answer 510

application-specific integrated circuit (ASIC)

Question 511

provides a highly available network backbone. Devices such as client and server computers should not be attached directly to the core. Its purpose should be kept simple: provide redundant traffic paths for data to continue to flow around the access and distribution layers of the network.

Answer 511

The core layer

Question 512

a monolithic core layer is implemented as a full mesh. This is impractical if there are large numbers of core switches, making the design less scalable. Two-tier hierarchical network topology where access layer switches connect directly to a full mesh core layer.

Answer 512

collapsed core model

Question 513

A logical network segment comprising a broadcast domain established using a feature of managed switches to assign each port a ____ ID. Even though hosts on two ______s may be physically connected to the same switch, local traffic is isolated to each ____, so they must use a router to communicate.

Answer 513

virtual LANs (VLANs)

Question 514

is the process of logically dividing an IP network into smaller subnetworks (subnets), with each subnet having a unique address.

Answer 514

At layer 3, subnetting

Question 515

The interconnections between switches are referred to as ___. Backbone link established between switches and routers to transport frames for multiple virtual LANs (VLANs).

Answer 515

trunks.

Question 516

VIDs are normally defined by the ________

Answer 516

IEEE 802.1Q standard.

Question 517

An untagged/access port uses the following port tagging logic:

Answer 517

If a frame is addressed to a port in the same VLAN on the same switch, no tag needs to be added to the frame. If the frame needs to be transported over a trunk link, the switch adds the relevant 802.1Q tag to identify the VLAN, and then forwards the frame over the trunk port.

Question 518

transmits voice traffic as data packets, rather than over circuit-based transmission lines.

Answer 518

Voice over IP (VoIP)

Question 519

The VLAN with ID 1 is referred to as the ______

Answer 519

default VLAN

Question 520

Unless configured differently, all ports on a switch default to being in _____

Answer 520

VLAN 1

Question 521

is one into which any untagged traffic is put when receiving frames over a trunk port. VLAN ID used for any untagged frames received on a trunk port. The same ID should be used on both ends of the trunk and the ID should not be left as the default VLAN ID (1). When a switch receives an untagged frame over a trunk, it assigns the frame to the native VLAN. Untagged traffic might derive from legacy devices such as hubs or older switches that do not support 802.1Q encapsulated frames.

Answer 521

A native VLAN

Question 522

Configuring a router's physical interface with multiple virtual interfaces connected to separate virtual LAN (VLAN) IDs over a trunk.

Answer 522

Subinterfaces

Question 523

Feature of layer 3 switches that allows a virtual interface assigned with an IP address to act as the default gateway for a VLAN. With layer 3 switches, each VLAN can be assigned a _________ to act as the default gateway.

Answer 523

Switch Virtual Interface (SVI)

Question 524

What is the primary difference between tagged and untagged ports regarding VLAN tags? -Tagged ports add a VLAN tag to all outgoing frames. -Untagged ports can transport traffic for multiple VLANs. -Tagged ports strip VLAN tags from incoming frames. -Untagged ports do not add or remove VLAN tags from frames within the same VLAN.

Answer 524

-Untagged ports do not add or remove VLAN tags from frames within the same VLAN.

Question 525

A network administrator wants to set up a switch with a voice or auxiliary Virtual Local Area Network (VLAN) to distinguish the PC and VoIP traffic without having to set up a trunk port. Which of the following commands should the administrator perform first? -interface GigabitEthernet0/0 -switchport mode access -switchport access vlan 100 -switchport voice vlan 101

Answer 525

-interface GigabitEthernet0/0

Question 526

Why is it recommended to change the native VLAN from its default setting? -To allow for more VLANs to be created -To reduce the risk of VLAN hopping attacks -To increase the speed of the network -To enable inter-VLAN routing

Answer 526

-To reduce the risk of VLAN hopping attacks

Question 527

may arise because a required static routing entry has not been entered or has been entered incorrectly. may also arise because a router fails to communicate with its neighbors and so does not receive routing protocol updates. Troubleshooting issue where a routing table does not contain a required entry due either to manual misconfiguration or failure of a dynamic routing protocol update.

Answer 527

A missing route

Question 528

Troubleshooting issue where a packet is forwarded between routers in a loop until its TTL expires. occurs when two routers use one another as the path to a network.

Answer 528

A routing loop; One symptom of a potential routing loop is for routers to generate ICMP Time Exceeded error messages.

Question 529

If the cost exceeds a certain value (16 in RIP), the network is deemed unreachable. A poison route is one advertised with a hop count of 16. This can provide an explicit failure notice to other routers.

Answer 529

Maximum hop count

Question 530

If a node declares a network unreachable, its neighbors start a holddown timer. Any updates about that route received from other nodes are discarded for the duration of the timer. This is designed to ensure that all nodes have converged information about an unreachable network.

Answer 530

Holddown timer

Question 531

Prevents a routing update from being copied back to the source. In the example above, this would prevent Router C from sending an update about a route to Router A via Router B to Router B.

Answer 531

Split horizon

Question 532

Routing protocols use various mechanisms to prevent loops. For example, distance vector protocols use the following mechanisms:

Answer 532

Maximum hop count holddown timer split horizon

Question 533

If you can ping a host's default gateway but cannot ping hosts on remote networks, what should you suspect? -A DNS issue -A routing issue -A firewall issue -A cable disconnection

Answer 533

-A routing issue; possibly due to a router going offline or a misconfiguration.

Question 534

What is the effect of a poison route in distance vector routing protocols? -It increases the hop count to the maximum to speed up convergence. -It advertises a route with a hop count of 16 to indicate the network is reachable. -It advertises a route with a hop count of 16 to indicate the network is unreachable. -It decreases the hop count to zero to indicate the network is directly connected.

Answer 534

-It advertises a route with a hop count of 16 to indicate the network is unreachable. A poison route is advertised with a hop count set to the maximum (e.g., 16 in RIP) to explicitly notify other routers that the network is unreachable, helping to prevent routing loops. Increasing the hop count to the maximum does not speed up convergence; it indicates unreachability.