S24-Troubleshooting Physical Networks

Question 1

100BASE-FX

Answer 1

Fiber
- MMF (Multi-mode Fiber)
- 100 Mbps
- 2 Kilometers

Question 2

100BASE-SX

Answer 2

• MMF
• 100 Mbps
• 300 m

Question 3

1000BASE-SX

Answer 3

-MMF
- 1000 Mbps
- 220-550 m

Question 4

1000BASE-LX

Answer 4

• SMF & MMF
• 1000 Mbps
• 5 kilometers / 550 m

Question 5

10GBASE-SR

Answer 5

• MMF
• 10 Gbps
• 400 m

Question 6

10GBASE-LR

Answer 6

• SMF
• 10 Gbps
• 10 Kilometers

Question 7

Rollover/Console Cable

Answer 7

A type of null-modem cable that is used to connect a computer terminal to a router’s console port

Question 8

Crossover cable

Answer 8

Connects two ethernet network devices directly

Question 9

Power over Ethernet (PoE)

Answer 9

Passes electrical power over twisted pair ethernet cable

Question 10

What is the minimum ethernet cable standard needed for PoE?

Answer 10

At least a Cat5e or better

Question 11

How much Power can PoE provide?

Answer 11

• 15.4 - 60 watts on 2 twisted pairs
• 60-100 watts using all 4 pairs

Question 12

Attenuation

Answer 12

Loss of signal strength on a wired network cable ore wireless signal

Question 13

Noise

Answer 13

Electrical or radio frequency interference/crosstalk

Question 14

Steps you can take to reduce copper cable Attenuation

Answer 14

1 - Use proper cables
2 - Shorten run distance
3 - Use an Amp or repeater

Question 15

What factors can cause attenuation on Fiber cables?

Answer 15

• Cheap construction
• Dirty connectors

Question 16

Steps you can take to reduce fiber cable Attenuation

Answer 16

1 - replace with new and/or higher quality cable
2 - Clean connectors

Question 17

Interference

Answer 17

occurs when Multiple cables on the same frequency operating in close proximity

Question 18

Decibel (dB) Loss

Answer 18

Amount of signal deterioration on a given connection

Question 19

what does dB Loss look like for copper and fiber cables?

Answer 19

Copper:
Voltage decrease

Fiber:
Lost light

Question 20

What tools test cable attenuation?

Answer 20

Copper:
- Cable Certifier
Fiber:
- Fiber light meter

Question 21

What tools test Interference?

Answer 21

Spectrum Analyzer

Question 22

What tools test Decibel loss?

Answer 22

Copper:
- Cable certifier/ Cable analyzer

Fiber:
- Fiber light meter

Question 23

What locations can an incorrect pinout occur with copper cabling?

Answer 23

• Patch Panel
• Wall Jack
• RJ45 connector

Question 24

What is usually the default pinout standard for patch panels?

Answer 24

TIA-568-B:
WO, O, WG, B, WB, G, WBr, Br

Question 25

What tool can you use to test a cable pinout

Answer 25

- Cable tester / Wire mapping tool

Question 26

What do you need to test an Ethernet port?

Answer 26

Loopback plug and specialized software

Question 27

Open

Answer 27

Break in electrical connection on the wires

Question 28

Short

Answer 28

connection within the cable/circuit creating an unintended path for electricity to flow

Question 29

What some common Fiber issues?

Answer 29

- Incorrect transceivers - Reversed Transmit and receiver - Dirty optical cables

Question 30

Tranceiver

Answer 30

Transmitter and receiver on a single device. Converts network interfaces

Question 31

Diameter of Multi Mode fiber cables

Answer 31

50 - 60 microns

Question 32

what does a solid orange activity light on an ethernet nic port indicate?

Answer 32

connection established between device and upstream device

Question 33

what does a blinking orange activity light on an ethernet nic port indicate?

Answer 33

data activity is happening between that device and upstream device

Question 34

What does each light level indicate on the link speed light on a NIC?

Answer 34

Green Light: - 1 Gbps Orange Light - 100 Mbps No light - 10 Mbps

Question 35

Duplex Mismatch

Answer 35

one device thinks the connection is full duplex and the other this its Half Duplex

Question 36

How can you prevent Duplex Mismatch?

Answer 36

Make sure both devices are configured to auto negotiate

Question 37

What is a Cyclic Redundancy (CRC) Error?

Answer 37

indicates that a data frame has been corrupted during transmission. the calculated CRC value at the receiving end doesn't match the CRC value received with the frame,

Question 38

What can increased CRC errors indicate?

Answer 38

Noise interference, physical issues impacting network conductivity: - Electrical Interference - Cable Damage - Hardware fault

Question 39

Runt

Answer 39

Frame that's smaller than the minimum frame size used on the network

Question 40

Giants

Answer 40

Frames that exceed the maximum frame size of a network

Question 41

Drops

Answer 41

Device's buffer is full and cannot take anymore frames/packets

Question 42

Error-Disabled

Answer 42

Port on a switch has been automatically shutdown by the network system due to a network Error or policy violation

Question 43

Administratively down

Answer 43

network port has been intentionally disabled by network admins

Question 44

Suspended Port

Answer 44

typically a result of a protocol/policy violation on the network

Question 45

What are the two types of Power over Ethernet (PoE) ?

Answer 45

POE POE+

Question 46

What is the IEEE Standard for PoE?

Answer 46

IEEE 802.3af - up to 15.4 watts DC - minimum 12.95 watts

Question 47

What is the IEEE Standard for PoE+?

Answer 47

IEEE 802.4at - up to 30 watts DC - Minimum 25.5 watts

Question 48

T/F Minimum Power provided by PoE is 15.4 watts

Answer 48

False, due to power loss during transmission actual minimum power is 12.95 watts

Question 49

Power Budget Exceeded Error

Answer 49

Power Draw from connected endpoints exceeds power supply capacity

Question 50

Power budget

Answer 50

All DC power available to the endpoint devices

Question 51

PoE Standard Error

Answer 51

PoE Standard unsupported by the device

Question 52

PoE Injector

Answer 52

Device that can supply power to a standard ethernet data cable