21. Manage Basic Network Settings

Question 1

1. What is a MAC address?

Answer 1

1. The media access control (MAC) address is used to identify a physical network interface on a local network.

Question 2

2. What’s the purpose of Internet Protocol v4 (IPv4) addresses and subnet masks?

Answer 2

2. The IP address identifies the location of a network device. IP addresses are the primary identification used by the Internet protocol suite TCP/IP for both LANs and WANs. Subnet masks are used by network devices to identify their local network range and to determine whether outgoing data is destined for a network device on the LAN.

Question 3

3. How are IPv4 addresses constructed?

Answer 3

3. Most common IP addresses and subnet masks share the same IPv4 formatting. An IPv4 address is a 32-bit number represented in four groups of three-digit numbers, known as octets, separated by periods. Each octet has a value between 0 and 255.

Question 4

4. How does the IP transfer messages between computers over a wide area network (WAN)?

Answer 4

4. A network client uses the subnet mask to determine whether the destination IP address is on the LAN. If the destination IP address isn’t, it assumes that the destination address is on another network, and the client sends the data to the IP address of the local network router. The network router then sends the data, through a WAN connection, to another router that it thinks is closer to the destination. This continues across WAN connections from router to router until the data reaches its destination.

Question 5

5. How is the Domain Name System (DNS) used to facilitate network naming?

Answer 5

5. The DNS is used to resolve a DNS name to the corresponding IP addresses.

Question 6

6. What’s used to identify a Wi-Fi network?

Answer 6

6. A Service Set Identifier, or SSID, is used to identify a Wi-Fi network name and associated configuration.

Question 7

7. Which Wi-Fi authentication protocols are supported by macOS High Sierra?

Answer 7

7. macOS High Sierra supports authenticated Wi-Fi by using the following authentication protocols: WEP, WPA/WPA2 Personal, and WPA/WPA2 Enterprise, which includes support for 802.1X authentication.

Question 8

8. How can macOS High Sierra automatically connect to a Wi-Fi network?

Answer 8

8. A new Mac can automatically connect only to Wi-Fi networks that have no standard authentication mechanism, known as an “open network.” However, a configured Mac can automatically reconnect to authenticated Wi-Fi networks, if the appropriate information was saved to the Keychain system.