23) Troubleshooting Cabling and Physical Issues

Flashcards covering cable types, transmission errors, interface metrics, port statuses, and hardware-specific issues for the CompTIA Network+ N10-009 exam.

Single Mode Fiber

A type of fiber optic cable used for long-distance transmissions with a smaller core that supports higher bandwidth with less signal attenuation.

Multimode Fiber

A type of fiber optic cable suitable for shorter distances with a larger core that allows multiple light modes but is prone to more signal dispersion and attenuation.

Signal Degradation

The diminishing of signal quality over distance or due to interference, often caused by incorrect cables, physical damage, EMI, or RFI.

Crosstalk

A specific type of signal degradation where a signal transmitted on one cable or channel interferes with a signal on another.

Near-End Crosstalk (NEXT)

A type of interference measured at the transmitting end of the communication.

Far-End Crosstalk (FEXT)

A type of interference measured at the receiving end of the communication.

Interference

The disruption of signal transmission caused by electromagnetic signals from other electronic devices or cables.

Attenuation

The gradual loss of signal strength as it travels through a cable or medium, which increases with distance.

Improper Termination

Occurs when network cables are not correctly terminated with appropriate connectors, leading to signal loss, reflection, and EMI.

TX/RX Transposition

A condition where the transmitter and receiver wires are incorrectly connected, resulting in complete communication failures between devices.

Interface Counters

Metrics that track various aspects of network traffic and errors used to identify potential performance issues.

Cyclic Redundancy Check (CRC) Errors

Errors occurring when there is a mismatch in the data checksum, indicating data corruption during transmission due to EMI, faulty cables, or hardware failures.

Runts

Packets that are smaller than the minimum allowed size, usually less than $64\,\text{bytes}$.

Giants

Packets that exceed the maximum allowed size, usually greater than $1518\,\text{bytes}$ for Ethernet frames.

Drops

Packets discarded due to network congestion, buffer overflow, or configuration issues.

Error Disabled

A port status where a network device automatically shuts down a port due to issues like security violations, excessive errors, or link flaps.

Administratively Down

A port status indicating the port has been manually disabled by a network administrator for maintenance or security.

Suspended

A port status where the port is temporarily disabled due to network policy violations or dynamic adjustments by protocols like LACP.

Power over Ethernet (PoE)

A technology that allows network cables to carry electrical power to devices such as IP cameras and wireless access points.

Power Budget Exceeded

A condition where the total consumption of connected PoE devices exceeds the switch's available power, causing devices to fail or operate intermittently.

PoE Standards

The specific IEEE standards (e.g., $802.3af$, $802.3at$, $802.3bt$) that determine compatibility and power delivery limits.

Transceivers

Modules used to connect network devices via fiber optic or copper cables; issues include mismatches or signal strength problems.