Networking Chapter 15
- 1. Network Troubleshooting Chapter 15
- 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