The basic physical components that connect computers to a network are often given insufficient attention, or worse, overlooked entirely. Network interface cards (NICs), cable types, and connection methods are often to blame for erratic or faulty connections. Yet it’s always tempting to skip physical connections when troubleshooting problems.

The next time you set out to repair network connections or order new networking hardware, take a moment to review some fundamentals you may have forgotten. If you’re having trouble remembering IRQ assignments, the differences between Layer 2 and Layer 3 switching, or a NIC’s port number, download our sample “Physical Components” chapter from Cisco Press’ Computer Networking Essentials book.

The chapter provides a handy reference for reviewing NIC types, properties of different network media, and other networking fundamentals. Keep track of cable types, transmission methods, network hardware differences, and more, with help from this Cisco Press excerpt. Download the sample chapter here.