Troubleshooting Physical Networks Flashcards
Network Troubleshooting Methodology: Step 1
- Identify the problem
Network Troubleshooting Methodology: Step 2
- Establish a theory to determine the cause
Network Troubleshooting Methodology: Step 3
- Test the theory to determine the cause
Network Troubleshooting Methodology: Step 4
- Establish a plan of action to resolve the problem and identify potential effects
Network Troubleshooting Methodology: Step 5
- Implement the solution or escalate as necessary
Network Troubleshooting Methodology: Step 6
- Verify the whole system functionality and if applicable, implement preventive
Network Troubleshooting Methodology: Step 7
7. Document findings, actions, outcomes, and lesson learned ▪ Gather more details ▪ Identify symptoms ▪ Check for changes ▪ Duplicate problem
Riser Cable
▪ Used to run network cables vertically between floors in a building in a
cable riser or elevator shaft
▪ Riser cables cannot be used in plenum spaces since they are not made
from PVC or FEP
Rollover/Console Cable
A cable that is used to connect a
computer to a router
Snips or Cutters
▪ Used to simply cut a piece of cable off a larger spool or run of cable
▪ Looks a lot like a pair of scissors, but uses stronger blades to cut twisted
copper cables, coaxial, cables, or even larger cable bundles
Cable strippers
▪ Strips the end of the cable to prepare it the attachment of a RJ-45 or
other type of connector
Cable Crimper
▪ Used to attach the connector to the end of the cable
▪ support both RJ-45 and RJ-11 connectors
▪ If you are working with coaxial cables, then you will need a cable crimper
that supports an RG-6 or RG-59 connector
Cable Tester
▪ Verifies continuity for each wire in the cable to ensure there are no
breaks
▪ Verifies the pinouts of the connectors
▪ Different testers for different cable types
Multi-tester
▪ Supports not just ethernet cables using RJ-45, but also BNC connectors
for coaxial cables, as well as IDE, PATA, SATA, RJ-45, fiber, DB25, DB9s
and anything else that you might need to test
Wire Map tool
Like a cable tester, but it works specifically for twisted pair ethernet
cables
▪ It can diagnose any issues with that cable
Open, short, reversed, crossed, split pairs
Cable Certifier
Used with an existing cable to determine its Category or data throughput
Multimeter
▪ Checks the voltage or the amperage or the resistance of a copper cable
▪ Used to verify if a cable is broken or not
▪ Used to check coaxial cables to ensure there is no cuts or breaks in the
middle of a patch cable, or test power sources or power cords
Punch-Down Tool
▪ Used to terminate wires on a punch-down block without stripping off the
insulation
▪ Used with 66 block or 110 block, network jacks, and patch panels
Toner Generator/Probe
▪ Allows technicians to generate a tone at one end of a connection and use
the probe to audibly detect the wire pair connected to the tone
generator
▪ Often called a “Fox and Hound”
▪ Fox is a tone generator
▪ Hound is a toner probe
Loopback Adapter
▪ Connects transmit pins (or fibers) to receive pins (or fiber) to test a
network interface
Time-domain Reflectometer (TDR)
▪ Locate breaks in a copper cable and provide an estimate of the severity
and the distance to the break
Optical Time-domain Reflectometer (OTDR)
Locate breaks in a fiber able and provide an estimate of the severity
and the distance to the break
Fiber Light Meter
A device that provides a continuous wave of stable source of energy for
attenuation measurements
Fusion Splicer
A machine that is used to permanently join two fibers together
Tap
▪ A simple device that connects directly to the cabling infrastructure to
split or copy packets for use in analysis, security, or general network
management
▪ Spectrum analyzer is a device that measures and displays signal
amplitude (strength) as it varies by frequency within its frequency range
Attenuation
▪ Loss of signal strength on a network cable or connection over the length
of the cable
▪ Twisted pair cables can transmit data over a maximum distance of 100
meters
▪ Coaxial cables can transmit data over a maximum distance of 500 meters
▪ The higher the frequency, the higher the bandwidth
Noise
Additional electrical or radio frequency noise in the areas where
your network cables are operating
o Use the proper cables for the physical environment you
are operating in
o Shorten the distance
o Use an amplifier or repeater
Fiber cleaning
Clean and polish both ends of fiber cable and connectors or switch to a
cable with higher quality
Interference
▪ Occurs when multiple cables in the same frequency band are operating in
close proximity to each other
▪ Use high quality twisted pair cables or higher category rated cables
▪ Plan cable runs to operate in parallel to any high power cables
Decibel (dB) Loss
▪ Measures the amount of signal deterioration we are experiencing on a given connection ● Copper o decrease in voltage ● Fiber o amount of lost light
Copper Cable Issues
Incorrect pinouts
Bad port
Open
Short
Bad port
If you suspect a bad port on a switch or router, you should
connect a loopback plug to the port on that device and run a test
using specialized software
Open
There is nothing on the other end of the connection or there’s a
break in the wires between the source and the destination
Short
Indicates there are two wires are connected together somewhere
in the connection
Fiber Cable Issues
Transceiver
Dry Cleaning
Wet Cleaning
Transceiver
▪ A transmitter and a receiver combined into a single device that converts a
network connection from one type to another
▪ They are designed to support a certain type of connection and a certain
cable type
Dry Cleaning
▪ Using light pressure while rubbing the end face of a fiber cable or
connector with a dry-cleaning cloth in one direction
Wet Cleaning
▪ Moistening a piece of lint-free cloth with a fiber optic cleaning solution
and wiping the end face of the cable or connector
Ethernet Issues
Duplex Mismatch
▪ When one device thinks the connection is full duplex and the other thinks
it is half duplex
▪ Ensure both devices are configured to auto negotiate the connection
properly
