1. Host-A has the IPv4 address and subnet mask 10.5.4.100 255.255.255.0. What is the network address of Host-A?

2. Host-A has the IPv4 address and subnet mask 172.16.4.100 255.255.0.0. What is the network address of Host-A?

3. Host-A has the IPv4 address and subnet mask 10.5.4.100 255.255.255.0. Which of the following IPv4 addresses would be on the same network as Host-A? (Choose all that apply)

4. Host-A has the IPv4 address and subnet mask 172.16.4.100 255.255.0.0. Which of the following IPv4 addresses would be on the same network as Host-A? (Choose all that apply)

5. Host-A has the IPv4 address and subnet mask 192.168.1.50 255.255.255.0. Which of the following IPv4 addresses would be on the same network as Host-A? (Choose all that apply)

6. Which two statements are correct about private IPv4 addresses? (Choose two.)

7. Which two statements are correct about public IPv4 addresses? (Choose two.)

8. Which organization or group of organizations receives IP addresses from IANA and is responsible for allocating these addresses to ISPs and some organizations?

9. Which devices will not forward an IPv4 broadcast packet by default?

10. Which two situations are the result of excessive broadcast traffic? (Choose two)

11. What is the prefix length notation for the subnet mask 255.255.255.224?

The binary format for 255.255.255.224 is 11111111.11111111.11111111.11100000. The prefix length is the number of consecutive 1s in the subnet mask. Therefore, the prefix length is /27.

12. How many valid host addresses are available on an IPv4 subnet that is configured with a /26 mask?

When a /26 mask is used, 6 bits are used as host bits. With 6 bits, 64 addresses are possible, but one address is for the subnet number and one address is for a broadcast. This leaves 62 addresses that can be assigned to network devices.

13. Which subnet mask would be used if 5 host bits are available?

The subnet mask of 255.255.255.0 has 8 host bits. The mask of 255.255.255.128 results in 7 host bits. The mask of 255.255.255.224 has 5 host bits. Finally, 255.255.255.240 represents 4 host bits.​

14. A network administrator subnets the 192.168.10.0/24 network into subnets with /26 masks. How many equal-sized subnets are created?

The normal mask for 192.168.10.0 is /24. A /26 mask indicates 2 bits have been borrowed for subnetting. With 2 bits, four subnets of equal size could be created.​

15. What subnet mask is represented by the slash notation /20?

The slash notation /20 represents a subnet mask with 20 1s. This would translate to: 11111111.11111111.11110000.0000, which in turn would convert into 255.255.240.0.

16. Which statement is true about variable-length subnet masking?

In variable-length subnet masking, bits are borrowed to create subnets. Additional bits may be borrowed to create additional subnets within the original subnets. This may continue until there are no bits available to borrow.

17. Why does a Layer 3 device perform the ANDing process on a destination IP address and subnet mask?

ANDing allows us to identify the network address from the IP address and the network mask.

18. How many usable IP addresses are available on the 192.168.1.0/27 network?

A /27 mask is the same as 255.255.255.224. This leaves 5 host bits. With 5 host bits, 32 IP addresses are possible, but one address represents the subnet number and one address represents the broadcast address. Thus, 30 addresses can then be used to assign to network devices.

19. Which su254bnet mask would be used if exactly 4 host bits are available?

The subnet mask of 255.255.255.224 has 5 host bits. The mask of 255.255.255.128 results in 7 host bits. The mask of 255.255.255.240 has 4 host bits. Finally, 255.255.255.248 represents 3 host bits.

20. Which two parts are components of an IPv4 address? (Choose two.)

An IPv4 address is divided into two parts: a network portion – to identify the specific network on which a host resides, and a host portion – to identify specific hosts on a network. A subnet mask is used to identify the length of each portion.

21. If a network device has a mask of /26, how many IP addresses are available for hosts on this network?

A /26 mask is the same as 255.255.255.192. This leaves 6 host bits. With 6 host bits, 64 IP addresses are possible, but one address represents the subnet number and one address represents the broadcast address. Thus 62 addresses can then be assigned to network hosts.

22. What does the IP address 172.17.4.250/24 represent?

The /24 shows that the network address is 172.17.4.0. The broadcast address for this network would be 172.17.4.255. Useable host addresses for this network are 172.17.4.1 through 172.17.4.254.

23. If a network device has a mask of /28, how many IP addresses are available for hosts on this network?

A /28 mask is the same as 255.255.255.240. This leaves 4 host bits. With 4 host bits, 16 IP addresses are possible, but one address represents the subnet number and one address represents the broadcast address. 14 addresses can then be used to assign to network devices.

24. What is the purpose of the subnet mask in conjunction with an IP address?

With the IPv4 address, a subnet mask is also necessary. A subnet mask is a special type of IPv4 address that coupled with the IP address determines the subnet of which the device is a member. ​

25. A network administrator is variably subnetting a network. The smallest subnet has a mask of 255.255.255.224. How many usable host addresses will this subnet provide?​

The subnet mask 255.255.255.224 is equivalent to the /27 prefix. This leaves 5 bits for hosts, providing a total of 30 usable IP addresses (2 5  = 32 – 2 = 30).