Chapter 5 of 5 · CompTIA Network+ N10-009
Network Troubleshooting
The methodology, cabling, service and performance faults, and the tools used to solve them.
- 6topics
- 30 minfast track
- 1diagrams and exhibits
- 24%of the exam
Topics in this chapter
Take them in order, or jump to the one you need.
- 1The Troubleshooting MethodologyLearn the seven step CompTIA network troubleshooting methodology, from identifying the problem to documentation, OSI based…Diagram5 min
- 2Cabling and Physical Interface IssuesTroubleshoot wrong cable types, crosstalk, attenuation, bad terminations, interface error counters, port states, duplex mismatch…5 min
- 3Troubleshooting Network Service IssuesTroubleshoot addressing, DHCP, DNS, VLAN, spanning tree, routing, ACL, certificate and time problems by matching symptoms to the…5 min
- 4Troubleshooting Performance IssuesDiagnose slow networks by measuring congestion, bottlenecks, latency, jitter and packet loss, and fix wireless interference…4 min
- 5Command Line and Software ToolsUse ping, traceroute, ipconfig, ifconfig, ip, nslookup, dig, arp, netstat, nmap and tcpdump, plus protocol analyzers and speed…6 min
- 6Hardware Tools and Discovery ProtocolsChoose cable testers, toners, TDR, OTDR, loopback plugs, multimeters and spectrum analyzers, and use LLDP and CDP to discover…5 min
About this chapter
What this chapter covers
Network Troubleshooting is about finding and fixing faults in an organized way. It covers the standard method, the common physical, service and performance problems, and the software and hardware tools that reveal their causes.
The chapter follows the fifth exam domain and has five syllabus topics. They are the troubleshooting methodology, cabling and physical interface issues, network service issues, performance issues, and the choice of tools and protocols.
How the topics fit together
The methodology is the frame, the problem pages show what goes wrong, and the tool pages show how to find out.
- The methodology gives the order of work from identifying the problem to documenting it.
- Cabling and interface issues cover layer 1 and layer 2 faults.
- Network service issues cover addressing, DNS, switching, routing and ACL faults.
- Performance issues cover congestion, latency, jitter, loss and wireless problems.
- Software and hardware tools show how to test, measure and locate each fault.
Use the OSI model as a map. Decide the layer the symptom points to, pick a tool for that layer, and test one thing at a time.
How to use these pages
Each topic page has the same shape, so you can skim for what you need.
- What it is: the idea in plain words.
- How it works: the mechanism, with diagrams, tables and example commands.
- What to remember for the exam: the facts to memorize.
- Common mistakes: the classic traps.
- Check yourself: three questions to test your understanding.
Read the pages in order the first time. Then use the exam facts and the questions for revision.
Ready for more practice?
The full CompTIA Network+ N10-009 question bank has 910 questions, with timed practice exams and an explanation for every answer.
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