ACSP Troubleshooting and Networking 5 — Questions and Answers
Question 1: After a macOS update, a user's USB-C hub no longer works. You isolate the issue to a specific kernel extension. Which macOS security feature most likely prevented it from loading?
- FileVault 2
- System Integrity Protection (SIP) (Correct answer)
- Gatekeeper
- Rapid Security Response
Correct answer: System Integrity Protection (SIP)
System Integrity Protection restricts third-party kernel extensions and requires user approval via System Settings > Privacy & Security before they can load.
Question 2: A shared Mac in a school lab intermittently drops its network connection. After checking cables and the switch port, which macOS log source would you examine first for recurring network interface errors?
- Console app filtered to 'kernel' messages or /var/log/system.log (Correct answer)
- Activity Monitor > Network tab
- System Information > Software > Installations
- Network Utility > Netstat
Correct answer: Console app filtered to 'kernel' messages or /var/log/system.log
Kernel-level network driver errors are written to the system log; filtering Console by process 'kernel' reveals interface resets, link-down events, and driver faults.
Question 3: What does the 'Renew DHCP Lease' button in System Settings > Network actually do?
- It resets the network interface hardware
- It releases the current IP lease and requests a new one from the DHCP server (Correct answer)
- It flushes the DNS cache
- It disconnects and reconnects the Wi-Fi radio
Correct answer: It releases the current IP lease and requests a new one from the DHCP server
Renewing the DHCP lease sends a DHCPRELEASE followed by a DHCPDISCOVER, allowing the Mac to get a fresh IP assignment from the DHCP server.
Question 4: A Mac is connected via Ethernet but you notice packets are being dropped. You run 'ping -c 20 8.8.8.8' and see 5% packet loss. Which hardware component should you suspect first?
- The Mac's RAM
- The Ethernet cable or the switch port (Correct answer)
- The Mac's GPU
- The Time Machine backup drive
Correct answer: The Ethernet cable or the switch port
Intermittent packet loss on a wired connection most commonly points to a faulty cable, a damaged RJ45 connector, or a failing switch port.
Question 5: Which macOS feature caches software updates and App Store content locally so devices on the same network download from the local cache instead of the internet?
- iCloud Drive
- Content Caching (Correct answer)
- AirDrop
- Personal Hotspot
Correct answer: Content Caching
Content Caching, enabled in System Settings > General > Sharing, stores Apple content locally and serves it to nearby devices, reducing WAN bandwidth usage.
Question 6: A user's iPhone shows full Wi-Fi signal bars but they are connected to a captive portal network at a hotel. The Mac shows the same issue. Which approach resolves captive portal authentication?
- Toggle Airplane Mode on and off
- Open a browser and navigate to any HTTP (not HTTPS) page to trigger the portal redirect (Correct answer)
- Forget the network and re-join it
- Change the DNS server to 1.1.1.1
Correct answer: Open a browser and navigate to any HTTP (not HTTPS) page to trigger the portal redirect
Captive portals intercept unencrypted HTTP requests to redirect to the login page; navigating to an http:// URL (not https://) triggers the redirect that HTTPS would block.
Question 7: When using Safe Mode (Safe Boot) to troubleshoot a Mac startup issue, which of the following does macOS NOT do during a Safe Mode boot?
- Run a basic check of the startup disk
- Load only required kernel extensions
- Delete font caches and some system caches
- Back up user data to iCloud automatically (Correct answer)
Correct answer: Back up user data to iCloud automatically
Safe Mode performs disk checks, loads only essential kexts, and clears some caches, but it does not trigger or modify iCloud backups.
ACSP Troubleshooting and Networking 5
After a macOS update, a user's USB-C hub no longer works.
You isolate the issue to a specific kernel extension.
Which macOS security feature most likely prevented it from loading?