ACSP Troubleshooting and Networking 2

Question 1

What is the 'ping' command used for in macOS network troubleshooting?

Accepted Answer

Ping sends ICMP Echo Request packets to a destination and measures round-trip time; used to verify connectivity, test if a host is reachable, and identify latency or packet loss

Answer

Ping establishes a TCP connection to a server to test if a web service is responding

Answer

Ping downloads a small test file from a server to measure network throughput and bandwidth

Answer

Ping is used to check the status of DNS resolution without testing network connectivity

Question 2

A Mac can connect to the local network but cannot reach the internet. What systematic troubleshooting steps should be taken?

Accepted Answer

Test local gateway ping, check DNS resolution, test internet IP ping, verify default route, then check ISP-side issues — narrowing from local to remote systematically

Answer

Immediately reinstall macOS since network issues cannot be diagnosed without a clean system

Answer

Reset all network settings by deleting the NetworkInterfaces.plist file and rebooting

Answer

Run First Aid on the startup disk as network issues are often caused by file system corruption

Question 3

What does 'traceroute' show in macOS network diagnostics?

Accepted Answer

Traceroute shows each network hop (router) between the Mac and destination, with latency at each hop — revealing where packets are delayed or dropped along the path

Answer

Traceroute shows the physical cable route that network traffic takes from the Mac to the destination server

Answer

Traceroute tests all network interfaces simultaneously and shows which provides the fastest path to a destination

Answer

Traceroute only works on local networks and cannot trace routes across the internet

Question 4

What is Wireless Diagnostics in macOS and how does a technician access it?

Accepted Answer

Wireless Diagnostics is a built-in macOS tool for analyzing Wi-Fi environment, logging connections, scanning channels, and capturing packets; accessed by Option-clicking the Wi-Fi menu bar icon and selecting 'Open Wireless Diagnostics'

Answer

Wireless Diagnostics is only available through Apple's developer portal and requires an Apple Developer account

Answer

Wireless Diagnostics is accessed from System Settings > Network > Advanced > Wireless Diagnostics tab

Answer

Wireless Diagnostics requires installing additional tools from Xcode Command Line Tools before it becomes available

Question 5

What does a 'Self-Assigned IP Address' (169.254.x.x) mean on macOS and how should it be resolved?

Accepted Answer

169.254.x.x is an APIPA (Automatic Private IP Addressing) address assigned when DHCP fails; indicates the Mac cannot reach the DHCP server — check cable/Wi-Fi connection, router DHCP status, and try 'Renew DHCP Lease'

Answer

169.254.x.x is a valid private IP range used by enterprise networks for internal communication

Answer

169.254.x.x means FileVault is blocking network access until the user logs in

Answer

169.254.x.x is the default IP address assigned to Ethernet before Wi-Fi is connected and resolves automatically

Question 6

What is Network Quality (networkQuality) command in macOS Monterey and later?

Accepted Answer

networkQuality is a built-in macOS command that measures internet connection quality including upload/download speed, latency under load (RPM), and responsiveness using Apple's infrastructure

Answer

networkQuality is a third-party speed testing tool that must be installed from Homebrew before use

Answer

networkQuality tests only LAN (local area network) performance and cannot measure WAN/internet speed

Answer

networkQuality is the command-line equivalent of the Wireless Diagnostics app for measuring Wi-Fi signal strength