Free CompTIA Network+ (N10-009) practice questions. Covers networking fundamentals, subnetting, protocols, security, and troubleshooting with full explanations.
This CompTIA Network+ (N10-009) practice test covers all five exam domains with questions at exam difficulty. Networking Fundamentals (23%) tests OSI model knowledge, IP addressing, and core protocols. Network Implementation (19%) covers routing, switching, wireless, and virtualisation. Network Operations (17%) addresses monitoring, documentation, and disaster recovery. Network Security (20%) tests threats, hardening, and access control. Network Troubleshooting (21%) tests systematic problem resolution using real-world scenarios.
Subnetting questions appear across multiple domains. For every subnetting question: identify the prefix length, calculate the block size (256 minus the last non-255 octet of the subnet mask), find the subnet boundaries (multiples of the block size), and determine which subnet the given IP falls in. Write out the subnets until you find the right one — under exam pressure, systematic working beats mental shortcuts.
Port number knowledge is tested throughout the exam — in protocol identification, firewall configuration scenarios, and troubleshooting questions. At minimum know: 21 FTP, 22 SSH, 23 Telnet, 25 SMTP, 53 DNS, 67/68 DHCP, 80 HTTP, 110 POP3, 143 IMAP, 443 HTTPS, 445 SMB, 3389 RDP. Many questions can be answered or eliminated purely from port number knowledge before reading the full question stem.
Further reading: CompTIA Network+ Official Certification Page