7 Network Troubleshooting Free Online FlashCards

What is the goal of systematic network troubleshooting?

Network troubleshooting is a controlled process that uses evidence to find and correct a fault while minimizing disruption.

How can the scope of a network fault guide diagnosis?

Compare affected and unaffected devices, users, locations, times, and applications. A fault isolated to one device suggests a local cause; shared impact points toward common infrastructure or policy.

What are three ways to organize troubleshooting by OSI layer?

Bottom-up starts at the physical layer and moves upward; top-down starts with the application and moves downward; divide and conquer tests a useful middle point and proceeds in either direction.

How should a troubleshooting theory be tested?

Choose a test that distinguishes likely causes, and decide in advance what each possible result would mean. If evidence disproves the theory, form another theory or escalate.

What makes a network fix a prudent choice?

Prefer the smallest reversible change that addresses the confirmed cause, after considering impact, authorization, maintenance windows, backups, and side effects.

What should happen after a network fix is implemented?

Confirm that the original task works and check related functions. Document symptoms, scope, tests, results, changes, and verification to support future diagnosis.

Why does a failed ping not prove an application is unavailable?

A failed ping does not prove an application is unreachable because ICMP may be filtered. Test the relevant service and port as well.

What can an IPv4 address in the 169.254.0.0/16 range indicate?

An IPv4 address in the 169.254.0.0/16 range commonly indicates that the client did not obtain its expected DHCP configuration.

What should you investigate when IP access works but hostname access fails?

If a service works by IP address but not by hostname, investigate DNS, including the configured DNS server, query response, records, caching, and server-side health.

How do bandwidth and throughput differ?

Bandwidth is network capacity; throughput is the rate actually achieved.

Why can Wi-Fi application throughput be below its advertised connection rate?

Wi-Fi is a shared, half-duplex medium, so its advertised connection rate is not the same as usable application throughput.

What details help diagnose a connection blocked by security policy?

Check the source and destination addresses, protocol, port, direction, and applicable rule order. Correlate timestamps with firewall, authentication, and system logs.