Network Troubleshooting Chapter 21

Question 1

What does nslookup do?

Answer 1

Command line tool, used to query DNS servers manually for specific records. Used when a tech needs to see if a DNS record even exists and confirm its value.

Question 2

Define Time-Domain Reflectometer (TDR)

Answer 2

Advanced cable tester, test lengths of cables and their continuity or their discontinuity and identifies the location of any discontinuity due to a bend break unwanted crimp and so on

Question 3

Define Optical Time-Domain Reflectometer (OTDR)

Answer 3

Tester for Fiber Optic Cable that determines continuity and reports the location of cable breaks.

Question 4

Define a Certifier

Answer 4

Device that test the cable to ensure it can handle its rated amount of capacity.

Question 5

Define Voltage Event Recorder

Answer 5

Tracks voltage over time by plugging into a power outlet
AKA Voltage Quality Recorder

Question 6

Define Protocol Analylizer

Answer 6

Tool that monitors the different protocols running at different layers on the network and that can give application session network and datalink layer information on every frame going through a network.

Question 7

Define Cable Stripper

Answer 7

Device that enables the creation of UTP cables

Question 8

Define Multimeter

Answer 8

Tool for testing voltage (AC/DC) resistance and continuity

Question 9

Define Toner

Answer 9

Generic term for two devices used together - a tone generator and a tone locater (probe) - to trace cables by sending an electrical signal along a wire at a particular frequency. The tone locater then emits a sound when it distinguishes that frequency. AKA Fox and Hound

Question 10

Define punch down tool

Answer 10

Specialized tool for connecting UTP wires to a 110-block
AKA 110-Punchdown Tool

Question 11

Define Wiremap

Answer 11

Test for cooper cables that checks not only for continuity but also that all the wires on both ends of the cable connect to the right spot. Also picks up shorts and crosswires.

Question 12

Define a Fiber Light Meter

Answer 12

Device that measures the intensity of light pulses within or at the terminal ends of fiber optic cables.

Question 13

Define Hostname (command)

Answer 13

Command line tool that returns the hostname of the computer its run on

Question 14

Define TraceRT (also TraceRoute) (Command)

Answer 14

Command line utility used to follow the bath a packet takes between too hosts

Question 15

Define ipconfig (command)

Answer 15

Command line utility for windows that displays current TCP IP configuration of the machine

MAC (ifconfig)
Linux (ip)

Question 16

Define Address Resolution Protocol (ARP)

Answer 16

Protocol in the TCP/IP suite used with the CMD of the same name to determine the MAC Address that corresponds with a particular IP Address.

Question 17

Define Ping (command)

Answer 17

Small ICMP message set to check for the presence and response of another system. ALSO command line utility that uses these messages to check the “Up/Down” status of an IP addressed host.

Question 18

Define Arping (command)

Answer 18

Command used to discover hosts on a network similar to ping but that relies on ARP instead of ICMP. Wont cross any routers.

Question 19

Define pathping (command)

Answer 19

Command line tool that combines the features of the ping command and tracert trace route commands

Question 20

Define dig (Domain Information Groper) (command)

Answer 20

Command line tool used in non windows systems used to diagnose DNS problems

Question 21

Define route (command)

Answer 21

Command to display and edit to a local systems routing table

Question 22

Define netstat (command)

Answer 22

Command line utility used to examine TCP/IP connections open on a given host. Once universal though it is being replaced by (ss) in linux

Question 23

Define Port Scanner

Answer 23

Program that probe ports on another system, logging the state of the scanned ports.

Question 24

Define Nmap

Answer 24

Popular open source network scanner, designed to scan a network and create a map of hosts and services by sending out packets and examining the responses, frequently used as a vunurablitity scanner.

Question 25

Define TCPDump

Answer 25

Command line packet line sniffing tool