Free CompTIA Network+ Practice Questions

Q1.A switch port shows the link as up and passing traffic, but throughput is poor and interface error counters are climbing. At which TWO OSI layers is the fault MOST likely located? (Choose TWO.)

• A.Layer 1
• B.Layer 2
• C.Layer 4
• D.Layer 5
• E.Layer 7

Domain: Networking Concepts

Q2.A technician troubleshooting an intermittent WAN outage has tested and disproved several theories, and the remaining diagnostics require access to the service provider's circuit, which the technician cannot reach. What should the technician do NEXT?

• A.Continue forming new theories using only internal equipment
• B.Establish a plan of action based on the last theory
• C.Escalate the issue to the service provider
• D.Implement a temporary workaround and monitor

Domain: Network Troubleshooting

Q3.An attacker ARP-poisons a victim and its gateway, then silently relays and records all traffic between them. Which TWO statements are accurate? (Choose TWO.)

• A.The relaying-and-recording stage is an on-path attack
• B.End-to-end encryption such as TLS would render the captured traffic unreadable
• C.The relaying-and-recording stage is a denial of service attack
• D.Dynamic ARP inspection would have no effect on this attack
• E.The attack primarily violates availability

Domain: Network Security

Q4.A security team needs to identify the top talkers consuming bandwidth and record conversation metadata for years without storing payloads. Which data source BEST fits?

• A.Flow data
• B.Packet capture
• C.SNMP polling
• D.Syslog

Domain: Network Operations

Q5.An engineer needs the smallest device count that still provides one collision domain per host and one broadcast domain for the whole segment. Which single device accomplishes this?

• A.Switch
• B.Hub
• C.Router
• D.Access point

Domain: Network Implementation

Q6.Multiple PoE+ cameras at the end of a large deployment fail to power on, although each switch port supports PoE+ individually. Which is the MOST likely cause?

• A.The cameras require crossover cables
• B.The switch's total PoE power budget is exhausted
• C.The cable runs exceed 100 meters
• D.The cameras require 802.3af instead of 802.3at

Domain: Networking Concepts

Q7.After replacing a failed switch, a technician confirms every VLAN passes traffic, phones register on the voice VLAN, the user confirms everything works, and a monitoring alert is added. What should the technician do NEXT?

• A.Test the theory to determine the cause
• B.Document findings, actions, outcomes, and lessons learned
• C.Implement the solution during the next change window
• D.Escalate to the vendor for hardware root-cause analysis

Domain: Network Troubleshooting

Q8.The office internet circuit is saturated because a client-to-site VPN routes all remote employee traffic, including streaming video, through headquarters. Which change BEST relieves congestion while keeping internal resources reachable?

• A.Configure full tunnel mode on all clients
• B.Migrate the VPN from TLS to IPsec
• C.Configure split tunnel mode on all clients
• D.Replace it with a site-to-site VPN

Domain: Network Security

Q9.Which THREE are valid DR rehearsal formats in rising order of realism and cost? (Select THREE.)

• A.Tabletop exercise
• B.Component validation
• C.Full failover test
• D.Penetration test
• E.SLA negotiation
• F.Business impact analysis

Domain: Network Operations

Q10.A server link shows up but file transfers are extremely slow, with climbing late collisions and CRC errors. The NIC is hard-coded to full duplex and the switch port is auto. Which is the MOST likely cause?

• A.A broadcast storm on the server's VLAN
• B.An MTU mismatch caused by jumbo frames
• C.A duplex mismatch between the NIC and the switch port
• D.An STP topology change blocking the port

Domain: Network Implementation