CNNA Exam 8 - Questions and Answers (Quiz Format)

Consider the following range of addresses: 2001:0DB8:BC15:00A0:0000:: 2001:0DB8:BC15:00A1:0000:: 2001:0DB8:BC15:00A2:0000:: ... 2001:0DB8:BC15:00AF:0000:: The prefix-length for the range of addresses is:

/60 Explanation: All the addresses have the part 2001:0DB8:BC15:00A in common. Each number or letter in the address represents 4 bits, so the prefix-length is /60.

Which two reasons generally make DHCP the preferred method of assigning IP addresses to hosts on large networks? (Choose two.) a). It eliminates most address configuration errors. b). It ensures that addresses are only applied to devices that require a permanent address. c). It guarantees that every device that needs an address will get one. d). It provides an address only to devices that are authorized to be connected to the network. e). It reduces the burden on network support staff.

a). It eliminates most address configuration errors. e). It reduces the burden on network support staff.

A company has a network address of 192.168.1.64 with a subnet mask of 255.255.255.192. The company wants to create two subnetworks that would contain 10 hosts and 18 hosts respectively. Which two networks would achieve that? (Choose two.) a). 192.168.1.16/28 b). 192.168.1.64/27 c). 192.168.1.128/27 d). 192.168.1.96/28 e). 192.168.1.192/28

b). 192.168.1.64/27 d). 192.168.1.96/28 Explanation: Subnet 192.168.1.64 /27 has 5 bits that are allocated for host addresses and therefore will be able to support 32 addresses, but only 30 valid host IP addresses. Subnet 192.168.1.96/28 has 4 bits for host addresses and will be able to support 16 addresses, but only 14 valid host IP addresses.

What is the prefix for the host address 2001:DB8:BC15:A:12AB::1/64? a). 2001:DB8:BC15 b). 2001:DB8:BC15:A c). 2001:DB8:BC15:A:1 d). 2001:DB8:BC15:A:12

b). 2001:DB8:BC15:A Explanation: The network portion, or prefix, of an IPv6 address is identified through the prefix length. A /64 prefix length indicates that the first 64 bits of the IPv6 address is the network portion. Hence the prefix is 2001:DB8:BC15:A.

A DHCP server is used to assign IP addresses dynamically to the hosts on a network. The address pool is configured with 192.168.10.0/24. There are 3 printers on this network that need to use reserved static IP addresses from the pool. How many IP addresses in the pool are left to be assigned to other hosts? a). 254 b). 251 c). 252 d). 253

b). 251

A network administrator is variably subnetting a network. The smallest subnet has a mask of 255.255.255.248. How many usable host addresses will this subnet provide?​ a). 4 b). 6 c). 8 d). 10 e). 12

b). 6

What is a result of connecting two or more switches together? a). The number of broadcast domains is increased. b). The size of the broadcast domain is increased. c). The number of collision domains is reduced. d). The size of the collision domain is increased.

b). The size of the broadcast domain is increased. Explanation: When two or more switches are connected together, the size of the broadcast domain is increased and so is the number of collision domains. The number of broadcast domains is increased only when routers are added.

What are two reasons a network administrator might want to create subnets? (Choose two.) a). simplifies network design b). improves network performance c). easier to implement security policies d). reduction in number of routers needed e). reduction in number of switches needed

b). improves network performance c). easier to implement security policies

How many bits must be borrowed from the host portion of an address to accommodate a router with five connected networks? a). two b). three c). four d). five

b). three Explanation: Each network that is directly connected to an interface on a router requires its own subnet. The formula 2n, where n is the number of bits borrowed, is used to calculate the available number of subnets when borrowing a specific number of bits.

How many host addresses are available on the network 172.16.128.0 with a subnet mask of 255.255.252.0? a). 510 b). 512 c). 1022 d). 1024 e). 2046 f). 2048

c). 1022 Explanation: A mask of 255.255.252.0 is equal to a prefix of /22. A /22 prefix provides 22 bits for the network portion and leaves 10 bits for the host portion. The 10 bits in the host portion will provide 1022 usable IP addresses (210 - 2 = 1022).

A network administrator wants to have the same network mask for all networks at a particular small site. The site has the following networks and number of devices: IP phones - 22 addresses PCs - 20 addresses needed Printers - 2 addresses needed Scanners - 2 addresses needed The network administrator has deemed that 192.168.10.0/24 is to be the network used at this site. Which single subnet mask would make the most efficient use of the available addresses to use for the four subnetworks? a). 255.255.255.0 b). 255.255.255.192 c). 255.255.255.224 d). 255.255.255.240 e). 255.255.255.248 f). 255.255.255.252

c). 255.255.255.224

Which subnet mask would be used if 5 host bits are available? a). 255.255.255.0 b). 255.255.255.128 c). 255.255.255.224​ d). 255.255.255.240

c). 255.255.255.224​ Explanation: 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.

A network administrator needs to monitor network traffic to and from servers in a data center. Which features of an IP addressing scheme should be applied to these devices? a). random static addresses to improve security b). addresses from different subnets for redundancy c). predictable static IP addresses for easier identification d). dynamic addresses to reduce the probability of duplicate addresses

c). predictable static IP addresses for easier identification

If a network device has a mask of /28, how many IP addresses are available for hosts on this network? a). 256 b). 254 c). 62 d). 32 e). 16 f). 14

f). 14 Explanation: 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.