N10-009
Free CompTIA Network+ Practice Test
12 exam-style questions with full explanations — no sign-up. Score yourself, then close your gaps with the full course.
Exam fee ~$3995 exam domainsLevel Beginner-Intermediate2 timed practice tests in the course
✅ Free practice — no sign-up📝 Real exam-style questions💡 Detailed explanations💸 30-day money-back via Udemy
A network administrator assigns the subnet 192.168.10.0/27 to a department. How many usable host addresses are available in this subnet?
A /27 mask (255.255.255.224) provides 32 total addresses (2^5). Subtracting the network address and broadcast address leaves 30 usable host addresses.
A network technician installs three switches in a redundant triangle topology to provide fault tolerance. Shortly after, users report a broadcast storm and severe network slowdowns. Which action should the technician take to BEST resolve this issue while preserving redundant links?
STP detects redundant Layer 2 paths between switches and places one or more ports into a blocking state to prevent a switching loop, while keeping the redundant physical links available as backups if the primary path fails.
A network administrator needs to identify which applications are consuming the most bandwidth across multiple WAN links over the past 30 days without capturing every packet. Which technology should be used?
Flow data (NetFlow/IPFIX) exports per-conversation summaries (source, destination, application, bytes) with low overhead, making it ideal for long-term traffic trend and top-talker analysis.
A company's public-facing web servers are being flooded with traffic from thousands of distributed source IP addresses, causing legitimate customers to be unable to reach the site. The internal network team has already confirmed the servers themselves are not misconfigured. Which solution BEST mitigates this attack?
A distributed flood from many source IPs targeting availability is a DDoS attack. Cloud-based scrubbing services absorb and filter volumetric traffic upstream before it reaches the network, which is the standard mitigation for this scale of attack.
A technician is troubleshooting a user's inability to access a file server. The technician has already identified the problem and established a theory that a recent firewall rule change is blocking the traffic. According to the CompTIA troubleshooting methodology, what should the technician do NEXT?
After establishing a theory of probable cause, the next step in the methodology is to test that theory to confirm it before moving to a plan of action.
A systems administrator needs to securely transfer files between two Linux servers, ensuring both the connection and the transferred data are encrypted. Which protocol and default port should be used?
SFTP (SSH File Transfer Protocol) runs over SSH on port 22, which encrypts both the control channel and the file data, meeting the encryption requirement.
A network engineer must connect two buildings located approximately 8 kilometers apart using a 10 Gigabit Ethernet single-mode fiber link. Which transceiver type BEST meets this requirement?
SFP+ LR transceivers are rated for single-mode fiber runs up to 10km, which comfortably covers the 8km distance at the lowest cost and power consumption suitable for the requirement.
Which SNMP version must be deployed to meet a security requirement for authenticated and encrypted network management traffic?
SNMPv3 introduces the User-based Security Model (USM), providing authentication (e.g., SHA) and encryption (e.g., AES) of management traffic, which v1 and v2c lack.
A penetration tester demonstrates that a crafted frame with two stacked 802.1Q tags can hop from the native VLAN onto a victim VLAN on a trunk link. Which action BEST prevents this VLAN hopping technique?
Double-tagging VLAN hopping relies on the native VLAN being untagged on the trunk and on ports negotiating trunking automatically. Moving the native VLAN off the default/data VLAN and disabling DTP so ports don't auto-negotiate trunk status closes both prerequisites for the attack.
A user reports that they cannot browse to 'intranet.company.local' by name, but they can successfully ping the server's IP address 10.10.5.20 directly. Which tool should the technician use FIRST to isolate the problem?
Since the IP is reachable but the hostname fails to resolve, nslookup (or dig) is the correct tool to query the DNS server and confirm whether name resolution is functioning.
Which IPv6 address type is automatically assigned to every interface and is used only for communication within the local network segment, never routed beyond it?
Link-local addresses (fe80::/10) are automatically generated on every IPv6-enabled interface and are confined to the local link; routers never forward packets with a link-local source or destination.
A small business is assigned a single public IPv4 address by its ISP but has 40 internal devices that all need simultaneous internet access. Which technology allows all internal devices to share the single public IP address at the same time?
PAT (also called NAT overload) maps multiple internal private IP addresses to a single public IP address by using unique source port numbers to distinguish each session, allowing many devices to share one public address simultaneously.
Ready for the real thing?
The full course: two full-length practice tests, video lessons for every exam domain, hands-on labs and detailed explanations.
undefined $34.99 with code E0363753E03D522425F4 — valid through Sep 23.
Get my $34.99 deal →N10-009 exam — quick answers
How much does the N10-009 exam cost?
The exam fee is approximately $399 and varies by region — confirm current pricing with the certification vendor before you book.
What topics are on the exam?
It covers 5 domains: Networking Fundamentals (23%), Network Implementations (21%), Network Operations (19%), Network Security (19%), Network Troubleshooting (18%). The full course has a dedicated chapter, lab and practice-test coverage for each.
Is this practice test really free?
Yes — all questions on this page are free with explanations and no sign-up. The paid Udemy course adds two full-length timed exams, video lessons and hands-on labs.
How do I get the discount?
Use code E0363753E03D522425F4 at checkout for $34.99 (list undefined) through Sep 23 — the enroll button applies it automatically.
Will this prepare me for the real exam?
The questions mirror the real exam's style and are mapped to the official domains. This is exam-focused preparation — combine the free test with the full course's timed simulations to gauge your readiness.