CompTIA Network+ domain #5: network troubleshooting [2022 update]

One of the most recognizable IT and information security networking certifications is Network+. As time goes on, new versions of certification exams are released, and Network+ releases the latest exam version, N10-008, in September of 2021. Some of the material covered in this latest exam version has changed and changes to Domain names. This article will detail Network+ Domain 5.0, entitled Network Troubleshooting, and explore what the Network+ cert is, what has changed since the last Network+ exam version, and the objectives and sub-objectives this Domain covers. If you are looking for a great starter to your Network+ exam outline for Domain 5.0, look no further.

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What is Network+?

Network+ is an IT and information security networking certification offered by CompTIA. This certification validates the skills and knowledge required to securely establish, maintain, and troubleshoot essential organization networks. This is one of the most popular networking certs on the market, with 500,000 cert holders worldwide. 

What has changed since the last Network+ exam version?

There have been some changes since exam version N10-007 that you need to be aware of. Aside from Domain name changes and slight changes to exam material weights, there have been sub-objective changes, especially on the foundational networking tools and technologies used to create secure networks. Below is a comparison of N10-007 and N10-008 (and their respective weights of exam material covered): 

While the name of Domain 5.0 (Network Troubleshooting) has dropped the “and Tools” part, the Domain still covers tools — but with revised sub-objectives covering appropriate network software and hardware tools to be used in different scenarios. The percentage of exam material that the new Domain 5.0 covers are unchanged, so you can expect around the same amount of exam questions as the N10-007 exam version. Let’s delve into the material covered by Domain 5.0.

Exam material covered by Domain 5.0: Network Troubleshooting

5.1 Explain the network troubleshooting methodology

1. Identify the problem

• Gather information
• Question users
• Identify symptoms
• Determine if anything has changed
• Duplicate the problem, if possible
• Approach multiple problems individually

2. Establish a theory of probable cause

• Question the obvious
• Consider multiple approaches
  • Top-to-bottom/ bottom-to-top OSI model
  • Divide and conquer

3. Test the theory to determine the cause

• If the theory is confirmed, determine the next steps to resolve the problem
• If the theory is not confirmed, reestablish a new theory or escalate

4. Other considerations

• Establish a plan of action to resolve the problem and identify potential effects
• Implement the solution or escalate as necessary
• Verify full system functionality and, if applicable, implement preventive measures
• Document findings, actions, outcomes, and lessons learned

5.2 Given a scenario, troubleshoot common cable connectivity issues and select the appropriate tools

1. Specifications and limitations

• Throughput
• Speed
• Distance

2. Cable considerations

• Shielded and unshielded
• Plenum and riser-rated

3. Cable application

• Rollover cable/console cable
• Crossover cable
• Power over Ethernet

4. Common issues

• Attenuation
• Interference
• Decibel (dB) loss
• Incorrect pinout
• Bad ports
• Open/short
• Light-emitting diode (LED) status indicators
• Incorrect transceivers
• Duplexing issues
• Transmit and receive (TX/RX) reversed
• Dirty optical cables

5. Common tools

• Cable crimper
• Punchdown tool
• Tone generator
• Loopback adapter
• Optical time-domain reflectometer (OTDR)
• Multimeter
• Cable tester
• Wire map
• Tap
• Fusion splicers
• Spectrum analyzers
• Snips/cutters
• Cable stripper
• Fiber light meter

5.3 Given a scenario, use the appropriate network software tools and commands

1. Software tools

• WiFi analyzer
• Protocol analyzer/packet capture
• Bandwidth speed tester
• Port scanner
• Iperf
• NetFlow analyzers
• Trivial File Transfer Protocol (TFTP) server
• Terminal emulator
• IP scanner

2. Command line tool

• Ping
• ipconfig/ifconfig/ip
• nslookup/dg
• traceroute/tracert
• arp
• netstat
• hostname
• route
• telnet
• tcpdump
• nmap

3. Basic network platform commands

• show interface
• show config
• show route

5.4 Given a scenario, troubleshoot common wireless connectivity issues

1. Specifications and limitations

• Throughput
• Speed
• Distance
• Received signal strength indication (RSSI) signal strength
• Effective isotropic radiated power (EIRP)/power settings

2. Considerations

• Antennas
  • Placement
  • Type
  • Polarization
• Channel utilization
• AP association time
• Site survey

3. Common issues

• Interference
  • Channel overlay
• Antenna cable attenuation/signal loss
• RF attenuation/signal loss
• Wrong SSID
• Incorrect passphrase
• Encryption protocol mismatch
• Insufficient wireless coverage
• Captive portal issues
• Client disassociation issues

5.5 Given a scenario, troubleshoot general networking issues

1. Considerations

• Device configuration review
• Routing tables
• Interface status
• VLAN assignment
• Network performance baselines

2. Common issues

• Collisions
• Broadcast storm
• Duplicate MAC address
• Duplicate IP address
• Multicast flooding
• Asymmetrical routing
• Switching loops
• Routing loops
• Rouge DHCP server
• DHCP scope exhaustion
• IP setting issues
  • Incorrect gateway
  • Incorrect subnet mask
  • Incorrect IP address
  • Incorrect DNS
• Missing route
• Low optical link budget
• Certificate issues
• Hardware failure
• Host-based/network-based firewall settings
• Blocked services, ports, or addresses
• Incorrect VLAN
• DNS issues
• NTP issues
• BYOD challenges
• Licensed feature issues
• Network performance issues

Earn your Network+ certification, guaranteed!

Enroll in an upcoming live online boot camp and earn your CompTIA Network+, guaranteed.

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Network+ Domain 5

Network+ is one of the most recognizable Networking certifications on the market today. To earn this certification, you first have to pass the cert exam. The exam contains 5 Domains of knowledge, with Domain 5.0 covering Network Troubleshooting. This article will prove to be a good start in building your exam preparation outline for this final Domain of the Network+ certification exam.

Sources:

•  Network+ Certification Exam Objectives, CompTIA
•  Network+ N10-007 vs. N10-008: What’s the Difference?, CompTIA