Study Guide
Networking is one of the largest domains on the Core 1 exam at 23%. You need to understand the OSI and TCP/IP models, common protocols and their port numbers, IP addressing and subnetting basics, wireless standards, network devices, and how to set up and troubleshoot SOHO networks.
The OSI model has 7 layers: Physical, Data Link, Network, Transport, Session, Presentation, Application. The TCP/IP model simplifies this to 4 layers: Network Access, Internet, Transport, Application. Data encapsulation adds headers at each layer. Knowing which layer protocols operate at is critical for the exam.
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Memorize these essential port numbers. TCP and UDP are transport protocols — TCP is connection-oriented and reliable, UDP is connectionless and faster. Many services use well-known port numbers that you must know for the exam.
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IPv4 addresses are 32-bit (written as four octets like 192.168.1.1). IPv6 addresses are 128-bit (written as eight hex groups). Private IP ranges: 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16. Subnet masks divide an IP into network and host portions. CIDR notation (/24) replaces the subnet mask.
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Wi-Fi standards are defined by IEEE 802.11. Each generation uses different frequencies and offers different speeds. 2.4 GHz has better range but lower speed; 5 GHz is faster but shorter range. Wi-Fi 6 (802.11ax) is the latest standard.
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Routers connect different networks and route traffic using IP addresses. Switches connect devices within a network using MAC addresses. Access points provide wireless connectivity. Firewalls filter traffic. A crimping tool attaches connectors to cables. A cable tester verifies cable continuity. A Wi-Fi analyzer identifies channel interference.
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