You’ve made a brilliant decision aiming for the CompTIA Network+ certification. Given the deluge of information on networking and limited time to prepare for the examination, it can be difficult to decide what aspects of Network+ are high-priority items to review.
Our CompTIA Network+ cheat sheet is handy as an overview or a refresher in such a predicament. It makes an excellent companion to our Security+ cheat sheet, which excludes Network+ material, and it goes deeper into major networking topics than those briefly mentioned in our A+ cheat sheet.
Keep this CompTIA Network+ cheat sheet handy by downloading it here. When you’re ready, let’s dive in.
About CompTIA Network+
The CompTIA Network+ exam tests your fundamental skills in essential computer networking functions.
You’ll need to answer at most 90 questions in this 90-minute examination and complete a survey after it ends. The passing score is 720 on a scale of 100–900.
The latest CompTIA Security+ exam code is N10-008, available from September 2021 to sometime in 2024. The exam objectives (domains) are as follows:
- About CompTIA Network+
- Domains
- Network Models
- Cabling and Topology
- Ethernet Basics
- Ethernet Standards
- Installing a Physical Network
- TCP/IP Basics
- Routing
- TCP/IP Applications
- Network Naming
- Securing TCP/IP
- Switch Features
- IPv6
- WAN Connectivity
- Wireless Networking
- Virtualization and Cloud Computing
- Data Centers
- Integrating Networked Devices
- Network Operations
- Protecting Networks
- Network Monitoring
- Network Troubleshooting
- Conclusion
- Frequently Asked Questions
Domains
This CompTIA Network+ cheat sheet arranges concepts according to our Total Seminars Network+ course subtopics. Diagrams put concepts into a visual form, and tables compartmentalize information. Here’s a key to finding items by domain:
Hashtag (Remember to type the # symbol) | Domain (N10-008) |
---|---|
#nf | Networking Fundamentals |
#ni | Network Implementations |
#no | Network Operations |
#ns | Network Security |
#nt | Network Troubleshooting |
Network Models
This section lays the foundation for all other Network+ sections.
Domain | Concept | Elaboration |
---|---|---|
#nf | OSI model | Open Systems Interconnect: 1. Physical 2. Data Link 3. Network 4. Transport 5. Session 6. Presentation 7. Application Memory aid: Please Do Not Throw Sausage Pizza Away |
#nf | Unicast/Broadcast | One/All network devices receive data |
#nf #ni | DHCP | Dynamic Host Configuration Protocol |
Cabling and Topology
Be careful: it’s easy to provide incorrect answers to exam questions related to the different fiber connector types.
Domain | Concept | Elaboration |
---|---|---|
#nf | Network topology | • Mesh • Star (hub-and-spoke) • Bus • Ring • Hybrid |
#nf | TIA/EIA-568A | 1. White/green 2. Green 3. White/orange 4. Blue 5. White/blue 6. Orange 7. White/brown 8. Brown |
#nf | TIA/EIA-568B | Swap “green” and “orange” in TIA/EIA-568A |
#nf | Coaxial | F-type, BNC |
#nf | Twinaxial/twinax | Has two inner conductors instead of one as in coaxial |
#nf | Twisted pair | RJ-45, RJ-11 |
#nf | STP/UTP | Shielded/Unshielded twisted pair |
#nf | Fiber optic | SC, ST, LC, FC, MT-RJ |
#nt | Plenum-rated | Fire-resistant cable; compare with riser-rated, non-plenum rated, and PVC |
#nf | Multimode/Single-mode | Cables carry LED/laser signals |
#nf | UTP category | Define speed and length of cables: • Cat 3 • Cat 5 • Cat 5e • Cat 6/6a • Cat 7 • Cat 8 |
Ethernet Basics
Recognizing the Ethernet naming syntax (10Base5, 100Base5, 1000Base5, 10Broad5, 10BaseT, etc.) is crucial to the Network+ exam.
Domain | Concept | Elaboration |
---|---|---|
#ni #nt | (Auto-)MDI-X | (Automatic) medium dependent interface crossover |
#ni #nt | Uplink port | Enable connection between two switches using a straight-through cable |
#ni #nt | CSMA/CD | Carrier sense multiple access with collision detection |
Ethernet Standards
Familiarize yourself with 1000Base and 10GBase types (names, distances, node numbers, cable types, etc.).
Domain | Concept | Elaboration |
---|---|---|
#nf | 100BaseT | Maximum cable length: 100m; max speed: 1,000 Mbps (1 Gbps) |
#nf | Half-duplex | For one-way communication |
#nf | Full-duplex | For simultaneous two-way traffic |
#nf | GBIC | Gigabit interface converter |
#nf | SFP, SFP+ | Small form-factor pluggable |
#nf | QSFP | Quad small form-factor pluggable |
#ni #nt | Switching/Bridging loop | Two or more data link layer paths between two endpoints |
#ni #nt | Layer 2 attack | Attacks on OSI model layer 2 (data link) |
#ni #nt | Flood guard | Block malicious traffic from entering a network |
Installing a Physical Network
Remember the following concepts in structured cabling:
Domain | Concept | Elaboration |
---|---|---|
#nf | 66-punchdown | Typically used in non-VoIP telephone systems |
#nf | 110-punchdown | For copper-wired networks |
#nf | Fiber distribution panel | For fiber-optic networks |
#nt | Wiremap | Simple test to confirm each wire terminates correctly |
#nt | TDR | Time domain reflectometer |
#nt | OTDR | Optical TDR |
#nt | NEXT | Near-end crosstalk |
#nt | FEXT | Far-end crosstalk |
#nf #ns #no | MDF | Main distribution frame |
#nf #ns #no | IDF | Intermediate distribution frame |
#nf #ns | U (unit) | Standard height for rack components; 19-inch wide and a multiple of 1¾-inch tall |
#nf #ns | Demarc | Separate the telecom company’s property from your responsibility |
TCP/IP Basics
Review additional information on IPv4 on your own.
Domain | Concept | Elaboration |
---|---|---|
#nf #ni | Internet Protocol (IP) | IPv4 and IPv6 |
#nf #ni | Transmission Control Protocol (TCP) | Connection-oriented |
#nf #ni | User Datagram Protocol (UDP) | Connectionless |
#nf #ni | IPv4 address | 32-bit number, consisting of four decimals from 0 to 255 separated by period (.), e.g., 192.168.1.1 |
#nf #ni | IPv4 loopback | 127.0.0.1 |
#nf #ni | APIPA/link-local | 169.254.x.x |
#nf #ni | Classless Inter-Domain Routing (CIDR) | CIDR IPv4 addresses have a prefix; e.g., “/24” in “10.150.23.58/24” denotes a 255.255.255.0 subnet mask. |
Routing
Review router-related abbreviations below.
Domain | Concept | Elaboration |
---|---|---|
#nf #ni | BGP | Border Gateway Protocol |
#ni | OSPF | Open Shortest Path First |
#ni | RIP | Routing Information Protocol |
#nf #ni | MTU | Maximum transmission unit |
#nf #ni | IGP/EGP | Interior/Exterior Gateway Protocol |
#nf | NAT | Network Address Translation |
#nf | PAT | Port Address Translation |
TCP/IP Applications
Remember to check out our Common Ports Cheat Sheet.
Network Naming
Network administrators cannot skip this section.
Domain | Concept | Elaboration |
---|---|---|
#nf | DNS | Domain Name System |
#nf | SOA | Start of authority |
#nf | A/AAAA | DNS record for IPv4/IPv6 |
#nf | CNAME | Canonical name or alias |
#nf | MX | Mail exchange |
#nf | PTR | Pointer record |
Securing TCP/IP
Review key network security acronyms here.
Domain | Concept | Elaboration |
---|---|---|
#ns | RADIUS | For authentication, authorization, and accounting |
#ns | TACACS+ | For access control |
#ns | Kerberos | For authentication and authorization on wired networks |
#ns | EAP | Extensible Authentication Protocol |
#ns | PEAP | Protected Extensible Authentication Protocol |
#nt | PKI | Public Key Infrastructure |
#ns | SAML | Security Assertion Markup Language |
Switch Features
The definition for VLAN (virtual local area network) is in the section Integrating Networked Devices.
Domain | Concept | Elaboration |
---|---|---|
#ni | VTP | VLAN Trunking Protocol |
#ni #ns #nt | STP | Spanning Tree Protocol |
#ni #ns #nt | BPDU | Bridge protocol data unit |
#ni #no | LACP | Link Aggregation Control Protocol |
#ni | QoS | Quality of service |
#ni | IDS | Intrusion detection system |
#ni | IPS | Intrusion prevention system |
IPv6
Here are IPv6 concepts for quick learning:
Domain | Concept | Elaboration |
---|---|---|
#nf #ni | NDP | Neighbor Discovery Protocol |
#nf #ni | IPv6 address | 128-bit hexadecimal number, e.g., 2001:7120:0000:8001: 0000:0000:0000:1F10 |
#nf #ni | IPv6 loopback | ::1 (unicast) |
#nf | VLSM | Variable-length subnet mask |
WAN Connectivity
Review additional information on WAN construction by yourself.
Wireless Networking
The ubiquity of mobile devices makes mastering wireless networking a necessity.
Domain | Concept | Elaboration |
---|---|---|
#ni | SSID | Service Set Identifier |
#ni | BSSID/ESSID | Basic/Extended Service Set Identifier |
#ni | CSMA/CA | Carrier-sense multiple access with collision avoidance |
#ni | DSSS | Direct-sequence spread-spectrum |
#ni | OFDM | Orthogonal frequency-driven multiplexing |
#ni | Wireless Ethernet versions | • 802.11a • 802.11b • 802.11g • (802.11i) • 802.11n • 802.11ac • 802.11ax |
#ni | PoE | Power over Ethernet • PoE injector • PoE+ 802.3af, 15.4 watts • PoE+ 802.3at, 30 watts |
#ni #nt | Wireless antennae | • Omni • Dipole • Patch • Directional/Yagi • Directional/Parabolic • SMA (SubMiniature version A) connector Gain measured in dBi |
#ni | WPA2 | Wi-Fi Protected Access version 2, encryption: CCMP-AES |
#nt | APIPA | Automatic Private IP Addressing |
#ns | Evil twin | Fake Wi-Fi access point to trick people into choosing it over the genuine one |
Virtualization and Cloud Computing
This section covers virtual machines and key ideas in cloud computing.
Data Centers
The prevalence of cloud computing makes learning about data centers a necessity.
Domain | Concept | Elaboration |
---|---|---|
#nf | FCoE | Fibre Channel over Ethernet |
#nf | FC | Fibre Channel |
#nf | HBA | Host bus adaptor |
#no | FHRP | First Hop Redundancy Protocol |
#no | VRRP | Virtual Router Redundancy Protocol |
#no | HSRP | Hot Standby Router Protocol |
#no | UPS | Uninterruptible power supply |
#no | HVAC | Heating, ventilation, and air conditioning |
#no | PDU | Power distribution unit |
Integrating Networked Devices
Know the differences between every type of “area network.”
Domain | Concept | Elaboration |
---|---|---|
#ni #ns | IoT | Internet of Things |
#nf #ni | VoIP | Voice over IP |
#ni | ICS | Industrial control systems |
#ni | SCADA | Supervisory control and data acquisition system |
#nf #ni | LAN | Local area network |
#nf | WLAN | Wireless local area network |
#ni | VLAN | Virtual LAN; split one broadcast domain into two |
#nf | CAN | Campus area network |
#nf | WAN | Wide area network |
#nf | SD-WAN | Software-defined wide area network |
#nf | MAN | Metropolitan area network |
#nf | PAN | Personal area network |
#nf | SAN | Storage area network |
Network Operations
Network operations cover the actions needed to protect a network and its associated organization. Two main risks are security and business.
Domain | Concept | Elaboration |
---|---|---|
#no #ns | NDA | Nondisclosure Agreement |
#no #ns | MOU | Memorandum of Understanding |
#no #ns #nf | MSA | Multi-Source Agreement |
#no #ns | SLA | Service Level Agreement |
#no #ns | BYOD | Bring Your Own Device |
#no #ns | SOW | Statement of Work |
#ns | Incident response | • Forensics • First responder • Secure the area • Document the scene • Collect evidence • Chain of custody • Forensics report • Legal hold • Electronic discovery (e-discovery) |
#no | RPO | Recovery point objective |
#no | RTO | Recovery time objective |
#no | MTTR | Mean time to repair |
#no | MTTF | Mean time to failure |
#no | MTBF | Mean time between failures |
#no | BCP | Business continuity plan |
#no #nt | AUP | Acceptable use policy |
#no #nt | MDM | Mobile Device Manager |
#no #nt | COBO | Corporate-owned, business only |
#no #nt | COPE | Corporate-owned, personally enabled |
#no #nt | CYOD | Choose your own device |
Protecting Networks
This is a vital section, especially if you intend to embark on a career in cyber security.
Domain | Concept | Elaboration |
---|---|---|
#ns | CIA triad | Confidentiality, integrity, availability |
#ns | Honeypot/honeynet | Individual/connected devices inviting attacks to capture information |
#ns #nt | Rogue DHCP server | IP address is outside of the network ID |
#ns | Screened subnet (demilitarized zone, DMZ) | Five components: • External network • External router • Perimeter network • Internal router • Internal network |
#ni #ns #nt | Man-in-the-middle (MITM)/on-path attack | Intercept a two-party conversation for one’s advantage. Tools: • Ettercap • Wireshark • tcpdump |
#ns | Spoofing | Digital misrepresentation • MAC • IP • VLAN |
#ni #ns | DTP | Cisco Dynamic Trunking Protocol |
#ns | ITAD | IT asset disposal |
#ns | DNS poisoning | Exploit known DNS vulnerabilities |
#ns | URL hijacking/typosquatting | Target URL typos |
#ns | Replay attack | Intercept data and replay later |
#ns | Downgrade attack | Force a network channel to switch to an unprotected or less secure data transmission standard |
#ns | Session hijacking | Seize control of a user’s browsing session to gain access |
#no #ns | Brute-force attack | Trying character combinations |
#no #ns | Dictionary attack | Using lists of probable passwords |
#ni #ns | VLAN hopping | Attacker can move from one VLAN to another |
#ns | CVE | Common vulnerabilities and exposure: publicly disclosed list of security flaws |
#ns | CNA | CVE Numbering Authority |
#ns | Zero-day | Flaw discovered by third party sooner than vendor |
#ni #ns | DAI | Cisco Dynamic ARP Inspection |
#ni #ns | RA | Router Advertisement |
#ni #ns | Control plane policing | Use QoS to stop Denial-of-Service attacks |
#ni #nt #ns | Firewall | Filter for network traffic. – Hardware/software – Stateful/stateless – Network-based/host-based – Context-/application-aware |
#ni #nt | UTM | Unified threat management |
#ni | ACL | Access control list |
#ni | DPI | Deep-packet inspection |
#ns | Virus | Run on a computer without the user’s knowledge. Examples: Boot Sector, Macro, Program, Polymorphic, Stealth, and Multipartite. |
#ns | Worm | Replicate itself across a network |
#ns | Trojan Horse | Perform useful functions superficially but runs malicious programs covertly |
#ns | Spyware | Spy on a computer and record its activities. Examples: keylogger and browser-hijacking adware |
#ns | Rootkit | Gain administrator-level access to the system core undetected |
#ns | Ransomware | Hold a computer hostage until the user pays |
#ns | Adware | Unwanted software displaying advertisements |
#ns | Remote Access Trojans (RATs) | Malware to remotely control an infected computer |
#ns | Logic bomb | Start a malicious program upon fulfillment of certain logical conditions |
#ns | Crypto-malware | Mine cryptocurrency that enriches perpetrators |
#ns | Physical controls | • Deterrent: ○ Preventative ○ Detective ○ Corrective • Recovery • Compensating controls |
Network Monitoring
Monitoring a network helps nip problems in the bud.
Domain | Concept | Elaboration |
---|---|---|
#ns | SIEM | Security Information and Event Management |
#nf #no #ns | SNMP | Simple Network Management Protocol |
#nf #no #ns | NMS | Network management system/station |
#no | Event Viewer, Syslog | Tools to display logs |
Network Troubleshooting
Apply the six technical troubleshooting steps (same as A+) to networking problems.
Domain | Concept | Elaboration |
---|---|---|
#nt | Additional considerations on the “establish theory” step | – Top-to-bottom/bottom-to-top – OSI model – Divide and conquer |
Conclusion
We hope this CompTIA Network+ cheat sheet helps your learning or career journey. Check out our other articles on networking, strictly exam-related test taking tips, and Network+ accelerated certification training programs, which include supplemental sample tests and chapter-end test questions. No matter where you go next, we wish you all the best.