ACMT Networking & Connectivity 1 — Questions and Answers
Question 1: A customer's MacBook cannot connect to Wi-Fi after a logic board replacement. What should the technician check first?
- Reinstall macOS
- Verify the Wi-Fi antenna cables are reconnected to the AirPort card on the logic board (Correct answer)
- Check the router settings
- Reset the customer's Apple ID
Correct answer: Verify the Wi-Fi antenna cables are reconnected to the AirPort card on the logic board
Wi-Fi antenna cables are frequently disconnected during logic board replacement; reattaching them is the first step when Wi-Fi fails after such a repair.
Question 2: Which tool in macOS provides detailed diagnostic information about Wi-Fi signal strength, noise, and channel?
- System Settings > Wi-Fi
- Wireless Diagnostics (Option + click Wi-Fi menu icon) (Correct answer)
- Network Utility
- Activity Monitor
Correct answer: Wireless Diagnostics (Option + click Wi-Fi menu icon)
Option-clicking the Wi-Fi menu icon provides signal strength and channel info; opening Wireless Diagnostics gives a full suite of Wi-Fi analysis tools.
Question 3: A Mac is connected via Ethernet but cannot reach the internet. The network shows 'Self-Assigned IP.' What does this indicate?
- The Ethernet cable is too long
- The Mac failed to obtain an IP address from the DHCP server, so it assigned itself a 169.254.x.x address (Correct answer)
- Wi-Fi is interfering with Ethernet
- The Mac's firewall is blocking traffic
Correct answer: The Mac failed to obtain an IP address from the DHCP server, so it assigned itself a 169.254.x.x address
A 169.254.x.x self-assigned IP (APIPA) indicates DHCP failure; the Mac could not reach the DHCP server, so it assigned itself a link-local address that does not route to the internet.
Question 4: Which command-line tool in macOS Terminal tests basic network connectivity by sending ICMP echo requests?
- traceroute
- ping (Correct answer)
- netstat
- nslookup
Correct answer: ping
'ping' sends ICMP echo requests to a target host and reports round-trip time and packet loss, making it the fundamental tool for testing basic network reachability.
Question 5: A MacBook Pro with Thunderbolt 3 does not recognize a connected Thunderbolt 3 external drive. What should the technician try first?
- Replace the logic board
- Try a different Thunderbolt 3 cable and a different Thunderbolt port on the Mac (Correct answer)
- Reset NVRAM
- Reinstall macOS
Correct answer: Try a different Thunderbolt 3 cable and a different Thunderbolt port on the Mac
Thunderbolt cables and ports can be faulty; testing with a different certified Thunderbolt 3 cable and an alternate port is the first non-invasive step.
Question 6: What is the purpose of the 'Renew DHCP Lease' button in System Settings > Network?
- It resets the Wi-Fi password
- It requests a new IP address from the DHCP server, resolving IP conflicts or expired lease issues (Correct answer)
- It disconnects and reconnects the Wi-Fi
- It flushes the DNS cache
Correct answer: It requests a new IP address from the DHCP server, resolving IP conflicts or expired lease issues
Renewing the DHCP lease forces the Mac to request a fresh IP address assignment from the router, resolving issues caused by expired leases or IP address conflicts.
ACMT Networking & Connectivity 1
A customer's MacBook cannot connect to Wi-Fi after a logic board replacement.
What should the technician check first?