CCNA Network Infrastructure and Connectivity Practice Test 13 — 15 Questions

Question 1

A host is configured with IP address 10.10.40.78/28. Which subnet contains that host?

Accepted Answer

10.10.40.64/28. A /28 subnet has a block size of 16. In simple terms, the fourth-octet ranges are 0–15, 16–31, 32–47, 48–63, 64–79, 80–95, and so on. Because 78 falls inside the 64–79 block, the network address for this host’s subnet is 10.10.40.64/28.

This style of subnetting question checks whether you can move from prefix length to block size and then place the host into the correct range. The common mistake is choosing the nearest familiar-looking number instead of the actual block boundary.

Answer

10.10.40.48/28

Answer

10.10.40.72/28

Answer

10.10.40.80/28

Question 2

A host is configured as 172.16.20.190/26. Which range contains the usable host addresses for that subnet?

Accepted Answer

172.16.20.129 to 172.16.20.190. A /26 uses blocks of 64 addresses. In practical terms, the fourth-octet ranges are 0–63, 64–127, 128–191, and 192–255. Since 190 falls inside the 128–191 block, the network address is .128 and the broadcast address is .191. That leaves .129 through .190 as the usable range.

This is a strong test of whether you can identify the correct block and then exclude the reserved boundary addresses correctly.

Answer

172.16.20.128 to 172.16.20.191

Answer

172.16.20.130 to 172.16.20.191

Answer

172.16.20.193 to 172.16.20.254

Question 3

Match each networking concept to its most accurate role.

Accepted Answer

Unicast: one-to-one communication. Unicast communication involves one-to-one transmission between a single sender and a single receiver. Broadcast is one-to-all communication, where a packet is sent to every device on the local subnet. Multicast is one-to-many communication, where a single sender transmits to a specific group of interested receivers. Anycast is one-to-one-of-many, where a packet is delivered to the nearest node among a group of potential receivers, typically used for services like DNS. The other options are incorrectly defined: Broadcast is not one-to-closest (that is anycast), Multicast is not one-to-all (that is broadcast), and Anycast is not one-to-group (that is multicast). Therefore, only option A is correctly matched.

Answer

Broadcast: one-to-closest communication

Answer

Multicast: one-to-all communication

Answer

Anycast: one-to-group communication

Question 4

A host address is 192.168.22.145/28. Which subnet contains that host?

Accepted Answer

192.168.22.144/28. A /28 prefix creates address blocks of 16. In practical terms, the fourth-octet ranges are 0–15, 16–31, 32–47, and so on. Because 145 falls inside the 144–159 range, the network address of the containing subnet is 192.168.22.144/28.

This type of question checks whether you can move from prefix length to block size and then place a host into the correct interval. The common mistake is choosing a nearby familiar number instead of calculating the actual block boundary.

Answer

192.168.22.128/28

Answer

192.168.22.160/28

Answer

192.168.22.148/28

Question 5

A host is configured with 10.10.10.33/27. What is the broadcast address of its subnet?

Accepted Answer

10.10.10.63. A /27 uses address blocks of 32. In practical terms, the ranges are 0–31, 32–63, 64–95, and so on. Because .33 falls inside the 32–63 block, the broadcast address is the last address in that block, which is 10.10.10.63.

This is a classic subnet-boundary question. The trick is to identify the correct block first and then choose its last address as the broadcast.

Answer

10.10.10.31

Answer

10.10.10.32

Answer

10.10.10.64

Question 6

A subnet must support at least 62 usable IPv4 host addresses. Which prefix is the most restrictive that meets the requirement?

Accepted Answer

/26. A /26 is the smallest valid answer. In practical terms, a /26 provides 64 total addresses and 62 usable host addresses after subtracting the network and broadcast addresses. A /27 would be too small because it provides only 30 usable hosts.

This is a standard minimum-prefix question because it checks whether you can work backward from the host requirement and choose the smallest subnet that fits.

Answer

/27

Answer

/25

Answer

/24

Question 7

A subnet must support at least 126 usable IPv4 host addresses. Which prefix is the longest that meets the requirement?

Accepted Answer

/25. A /25 is the smallest valid answer. In practical terms, a /25 provides 128 total addresses. After subtracting the network and broadcast addresses, 126 usable hosts remain. A /26 would be too small because it supports only 62 usable hosts.

This is a typical minimum-prefix question. The goal is to choose the smallest subnet that satisfies the host requirement without wasting more address space than necessary.

Answer

/26

Answer

/24

Answer

/27

Question 8

Which prefix length corresponds to the subnet mask 255.255.255.192?

Accepted Answer

/26. The mask 255.255.255.192 corresponds to /26. In practical terms, the first three octets contribute 24 network bits, and 192 in binary is 11000000, which contributes 2 more network bits. That totals 26 network bits.

This is a standard conversion skill that matters in subnetting, ACL design, and route interpretation.

Answer

/25

Answer

/27

Answer

/28

Question 9

A host is configured with 192.168.60.33/26. Which address is the network address of its subnet?

Accepted Answer

192.168.60.0. A /26 uses blocks of 64 addresses. In practical terms, the fourth-octet ranges are 0–63, 64–127, 128–191, and 192–255. Since 33 falls within the 0–63 block, the network address is 192.168.60.0.

This is a straightforward boundary-identification question, but it catches people who memorize masks without understanding block sizes. The right approach is to find the correct block first, then take the first address in that block as the network address.

Answer

192.168.60.32

Answer

192.168.60.64

Answer

192.168.60.63

Question 10

A host is configured with 192.168.10.129/25. Which subnet contains that host?

Accepted Answer

192.168.10.128/25. A /25 divides the /24 into two blocks: 0–127 and 128–255. In practical terms, 192.168.10.129 belongs to the upper half, so the containing subnet is 192.168.10.128/25.

This is a simple subnet-boundary question, but it is designed to confirm that you can identify the correct half of the /24 quickly and confidently.

Answer

192.168.10.0/25

Answer

192.168.10.64/25

Answer

192.168.10.192/25

Question 11

A subnet uses network address 192.168.200.96/28. Which range contains the usable host addresses?

Accepted Answer

192.168.200.97 to 192.168.200.110. A /28 block contains 16 addresses. In practical terms, the block starting at 192.168.200.96 runs through 192.168.200.111. The first address is the network address and the last address is the broadcast address. That means the usable host range is 192.168.200.97 through 192.168.200.110.

This question checks whether you can calculate the correct block and then exclude the two reserved boundary addresses.

Answer

192.168.200.96 to 192.168.200.111

Answer

192.168.200.98 to 192.168.200.111

Answer

192.168.200.81 to 192.168.200.94

Question 12

A host is configured with IP address 172.16.100.222/27. Which address is the broadcast address for its subnet?

Accepted Answer

172.16.100.223. A /27 uses address blocks of 32. In practical terms, the fourth-octet ranges are 0–31, 32–63, 64–95, 96–127, 128–159, 160–191, 192–223, and 224–255. Since 222 falls inside the 192–223 block, the broadcast address is the last address in that block, which is 172.16.100.223.

This is a classic subnet-boundary question because it tests whether you can place a host in the correct block and then identify the final address in that block as the broadcast.

Answer

172.16.100.191

Answer

172.16.100.224

Answer

172.16.100.255

Question 13

Match each IPv4-related concept to its most accurate role.

Accepted Answer

IPv4 address. The IPv4 address uniquely identifies a host on an IP network. The subnet mask distinguishes the network and host portions of the address, determining the local subnet. The default gateway is the router interface that forwards traffic to destinations outside the local subnet. The DNS server resolves domain names to IP addresses, enabling name-based communication. Each concept plays a distinct and essential role in IPv4 networking.

Question 14

Which two statements accurately compare SLAAC and DHCPv6?

Accepted Answer

SLAAC allows a host to form its own address using information from router advertisements.. SLAAC and DHCPv6 are both IPv6 host-configuration approaches, but they are not the same. In practical terms, SLAAC lets a host build its own address using router advertisements and the advertised prefix, while DHCPv6 can be used to provide addressing information or other configuration in a more server-driven way. Depending on design, IPv6 networks can use one, the other, or a mixture of behaviors.

The key is not to oversimplify. SLAAC is not “IPv6 DHCP,” and DHCPv6 is not the only way IPv6 hosts learn how to operate. Router advertisements remain very important.

Answer

SLAAC requires NAT to function.

Answer

DHCPv6 replaces the need for router advertisements completely.

Answer

Neither SLAAC nor DHCPv6 can provide any addressing information to hosts.

Question 15

Match each IPv6 address type or concept to its most accurate description.

Accepted Answer

Global Unicast: Routable over the public internet, assigned by RIRs.. Each IPv6 address type has a distinct purpose: Global Unicast for public routing, Link-Local for local segment, Unique Local for private site, Multicast for group communication, Anycast for nearest device, and SLAAC for stateless address assignment.

Answer

Link-Local: Routable across the entire enterprise network, used for inter-VLAN routing.

Answer

Unique Local: Globally unique and routable on the public internet, similar to Global Unicast.

Answer

Multicast: Used for one-to-one communication between two specific hosts.