Network+ Study Guide
Full N10-009 reference in one place — OSI, ports, protocols, cabling, wireless, IP, routing, security, and cloud.
CompTIA Network+ Certification
Exam Code: N10-009 • Updated for 2026 • 90 Questions • 90 Minutes
Entry-LevelIndustry Standard
Section
OSI Model Memory Aid
Use these mnemonics for layer order on the exam.
Top to bottom (7→1)
All People Seem To Need Data Processing
Bottom to top (1→7)
Please Do Not Throw Sausage Pizza Away
7
Application Layer
End-user services and application protocols
HTTPHTTPSFTPSMTPDNSDHCP
DevicesApplication FirewallWeb Server
PDUData
6
Presentation Layer
Data formatting, encryption, and compression
SSL/TLSJPEGMPEGASCIIEBCDIC
DevicesGateway
PDUData
5
Session Layer
Session establishment, maintenance, and termination
NetBIOSRPCPPTPL2TP
DevicesGateway
PDUData
4
Transport Layer
End-to-end connections and reliability
TCPUDPPort NumbersFlow Control
DevicesLoad Balancer
PDUSegment (TCP) / Datagram (UDP)
3
Network Layer
Logical addressing and routing
IPICMPIGMPIPv4/IPv6ARP
DevicesRouterLayer 3 Switch
PDUPacket
2
Data Link Layer
Physical addressing and frame formatting
MAC AddressEthernetPPP802.11 (Wi-Fi)
DevicesSwitchBridgeWAPNIC
PDUFrame
1
Physical Layer
Physical transmission of raw bits
CablesFiberRadio WavesVoltageHubs
DevicesHubRepeaterModemCable
PDUBit