CompTIA Network+ Network+ Troubleshooting Tools and Methods 3

Question 1

A technician runs 'nslookup mail.company.com' and receives a different IP than expected. What should be checked next?

Accepted Answer

DNS server records and potential DNS poisoning

Answer

An unexpected DNS response could indicate stale DNS records or DNS cache poisoning that must be investigated on the DNS server.

Question 2

Which tool would a technician use to measure the exact length of a copper cable run and identify where a break occurs?

Accepted Answer

TDR (Time Domain Reflectometer)

Answer

A TDR sends a signal down the cable and measures the time for reflection to calculate cable length and pinpoint faults.

Question 3

After replacing a NIC, a workstation cannot communicate with any host. Ping to 127.0.0.1 succeeds but ping to the default gateway fails. What is the MOST likely cause?

Accepted Answer

The NIC driver is not installed correctly

Answer

Loopback success confirms TCP/IP is functional, but failure to reach the gateway after a NIC replacement most likely means the driver is missing or faulty.

Question 4

A network map shows an unknown device with IP 192.168.1.254 that does not appear in DHCP leases. What tool would BEST identify this device?

Accepted Answer

Nmap port/OS scan

Answer

Nmap can perform host discovery and OS fingerprinting to identify unknown devices on a network segment.

Question 5

A user reports intermittent packet loss. You run iperf between two hosts and see consistent 2% loss. What should you check NEXT?

Accepted Answer

Interface error counters on the switch ports

Answer

Consistent measured packet loss points to a physical or link-layer issue best revealed by checking interface error counters on the connecting switch ports.

CompTIA Practice Test

CompTIA Practice Test

CompTIA Network+ Network+ Troubleshooting Tools and Methods 3