9.4.3 IPv4 Addressing Quiz Answers. Networking Basics Module 9 quiz exam answers
1. Which statement describes one purpose of the subnet mask setting for a host?
- It is used to describe the type of the subnet.
- It is used to identify the default gateway.
- It is used to determine to which network the host is connected.
- It is used to determine the maximum number of bits within one packet that can be placed on a particular network.
Explanation: An IPv4 address contains two portions. The network portion defines the network (or a subnet) where the host is located and the host portion identifies the host address on the network. The subnet mask is used to define the network portion of the IPv4 addressing through the logical ANDing of the IP address and the subnet mask.
2. What is one reason for subnetting an IP network?
- to reduce the scope of broadcast flooding
- to increase the number of available host addresses on the network
- to remove the need for network services that rely on broadcasts, such as DHCP
- to ensure that all devices can communicate with each other without requiring a router
Explanation: In flat networks where all hosts are on the same network, broadcast packets can quickly degrade the quality of the network performance. With the creation of smaller subnets, the broadcast traffic is isolated from other areas on the network. Devices on one subnet need to send traffic to a router to reach a host on a different subnet, and routers do not typically forward broadcast traffic.
3. A message is sent to all hosts on a remote network. Which type of message is it?
- limited broadcast
- multicast
- directed broadcast
- unicast
Explanation: A directed broadcast is a message sent to all hosts on a specific network. It is useful for sending a broadcast to all hosts on a nonlocal network. A multicast message is a message sent to a selected group of hosts that are part of a subscribing multicast group. A limited broadcast is used for a communication that is limited to the hosts on the local network. A unicast message is a message sent from one host to another.
4. A user is unable to access the company server from a computer. On issuing the ipconfig command, the user finds that the IP address of the computer is displayed as 169.254.0.2. What type of address is this?
- private
- link-local
- loopback
- experimental
Explanation: IPv4 addresses in the address block 169.254.0.0 to 169.254.255.255 are link-local addresses. The operating system of a host can automatically assign an address from this block to the host in case no IP configuration is available. An example is when a host is configured to obtain a dynamic IP address but cannot reach any DHCP server during the boot process. In such a case, the operating system can assign a link-local address.
5. Which three IP addresses are private ? (Choose three.)
- 10.1.1.1
- 172.32.5.2
- 192.167.10.10
- 172.16.4.4
- 192.168.5.5
- 224.6.6.6
Explanation: The private IP addresses are within these three ranges:
- 10.0.0.0 – 10.255.255.255
- 172.16.0.0 – 172.31.255.255
- 192.168.0.0 – 192.168.255.255
6. Match each description with an appropriate IP address.
Explanation: Place the options in the following order:
| 127.0.0.1 | loopback address |
| 240.2.6.255 | an experimental address |
| 198.133.219.2 | a public address |
| 169.254.1.5 | a link-local address |
7. Which network device can serve as a boundary to divide a Layer 2 broadcast domain?
- router
- Ethernet bridge
- Ethernet hub
- access point
Explanation: Layer 1 and 2 devices (LAN switch and Ethernet hub) and access point devices do not filter MAC broadcast frames. Only a Layer 3 device, such as a router, can divide a Layer 2 broadcast domain.
8. What is the role of IANA?
- maintaining standards related to electrical wiring and connectors
- documenting developments for new protocols and updating existing protocols
- managing the allocation of IP addresses and domain names
- promoting the development and evolution of the Internet around the world
Explanation: Four very important organizations that create and maintain open standards are:
- The Internet Assigned Numbers Authority (IANA) oversees and manages the allocation of IP addresses and domain names to preserve their uniqueness.
- The Electronic Industries Alliance (EIA) maintains standards related to wiring and connectors to ensure cabling interoperability between different devices.
- The Internet Engineering Task Force (IETF) maintains the technologies and protocols used on the internet, such as TCP/IP.
- The Internet Society (ISOC) promotes the use of the internet around the world.
9. Which address prefix range is reserved for IPv4 multicast?
- 240.0.0.0 – 254.255.255.255
- 224.0.0.0 – 239.255.255.255
- 169.254.0.0 – 169.254.255.255
- 127.0.0.0 – 127.255.255.255
Explanation: Multicast IPv4 addresses use the reserved class D address range of 224.0.0.0 to 239.255.255.255.
10. A high school in New York (school A) is using videoconferencing technology to establish student interactions with another high school (school B) in Russia. The videoconferencing is conducted between two end devices through the internet. The network administrator of school A configures the end device with the IP address 209.165.201.10. The administrator sends a request for the IP address for the end device in school B and the response is 192.168.25.10. Neither school is using a VPN. The administrator knows immediately that this IP will not work. Why?
- This is a loopback address.
- This is a link-local address.
- This is a private IP address.
- There is an IP address conflict.
Explanation: The IP address 192.168.25.10 is an IPv4 private address. This address will not be routed over the internet, so school A will not be able to reach school B. Because the address is a private one, it can be used freely on an internal network. As long as no two devices on the internal network are assigned the same private IP, there is no IP conflict issue. Devices that are assigned a private IP will need to use NAT in order to communicate over the internet.
11. A host is transmitting a broadcast. Which host or hosts will receive it?
- all hosts in the same network
- a specially defined group of hosts
- the closest neighbor on the same network
- all hosts on the internet
Explanation: A broadcast is delivered to every host that has an IP address within the same network.