2. Objectives
• Describe appropriate troubleshooting tools
and their functions
• Analyze and discuss the troubleshooting
process
• Tackle a variety of troubleshooting
scenarios
3. • Cable Testers, TDRs, and OTDRs
– Devices to test for broken cables
• Cable testers
– Detect continuity problems
– Detects if a wire map isn’t correct
• b. TDRs
– Time domain reflectometer
– Identifies the location of a cable break
– Works with copper cables
4. • OTDRs
– Optical time domain reflectometers (OTDR)
– Identifies the location of a cable break
– Works with fiber-optic cables
5. • Wi-Fi protected access (WPA) A way of
enabling wireless encryption
– Certifiers
• Only use for slowdowns, not for disconnects
• Require a loopback on the far end of cable run
• Ensure that a cable can handle its rated capacity
– Voltage Event Recorder/Temperature Monitor
• Detect power and heat problems
• Cause intermittent problems
6. • Protocol Analyzers
– Monitor protocols at different layers
– Application, Session, Network, and Data Link
layers
– Both hardware and software tools
• Cable Stripper/Snip
– Enables you to make UTP cables
– Also need crimpers
– Often combined in one tool
7. • Multimeters
– Test AC and DC voltage
– Test resistance
• Test continuity
• A great fallback when you do not have a cable tester.
• Tone Probes and Tone Generators
– Work together to identify opposite ends of unlabeled
cable runs
– Tone generator puts a signal (tone) on wire
– Tone probe on opposite end detects the signal
8. • Butt Sets
– Hand set
– Use to tap into a 66- or 100-block to test a line
• 8. Punchdown Tools
– Put UTP wires into 66- and 110-blocks
– Repunch a connection to make sure contacts are
set
9. • Software tools
– TRACERT/TRACEROUTE
• Traces all routers between two points
• Use to discover where a problem lies
• Displays IP settings
– IPCONFIG without parameters
• Basic information only
– Ipconfig /all gives configuration details
10. • PING and ARP PING
– PING
• Queries by name or IP address
• Uses ICMP packets
• Works across routers
• Problem: devices can block ICMP
11. • ARP PING
– Queries by IP address
– Uses ARP packets
– Problem: does not cross routers
– Only on UNIX and UNIX-like systems
12. • NSLOOKUP/DIG
– Both diagnose DNS problems
– NSLOOKUP (all operating systems)
• Poor tool
• Considered obsolete
• Without switches provides name (if available) and IP
address of default DNS server
• DIG (everyone but Windows)
– More powerful
