CCNA Practice Test 32 — 15 Questions

Question 1

A subnet has the network address 192.168.20.128/26. What is the broadcast address?

Accepted Answer

192.168.20.191. A /26 subnet uses blocks of 64 addresses. In plain language, the block that starts at 192.168.20.128 runs through 192.168.20.191. The first address in that block is the network address, and the last address is the broadcast address. That means the broadcast address is 192.168.20.191.

This is a standard subnetting calculation. Once the block size is identified, the broadcast address is simply the last address in the block.

Answer

192.168.20.159

Answer

192.168.20.192

Answer

192.168.20.255

Question 2

R1 and R2 are connected via a GigabitEthernet link in the same IPv4 subnet, and both routers have OSPF configured in the same area. However, R1 is not learning any OSPF routes from R2. What is the most likely cause?

Accepted Answer

GigabitEthernet0/0 is configured as a passive OSPF interface on R1.. The most likely reason is that one side has the interface configured as passive, which prevents OSPF hello packets from being sent on that interface. In practical terms, the network statement alone does not guarantee neighbor formation. OSPF still needs active neighbor discovery on the link. If the interface is passive, the router advertises the connected network into OSPF but does not attempt to form an adjacency there.

This is a realistic routing troubleshooting pattern because the configuration can look mostly correct until you inspect the passive-interface setting.

Answer

The routers must use different OSPF process IDs to exchange routes.

Answer

The routers are in different IPv4 subnets.

Answer

OSPF can advertise routes only across serial links.

Question 3

Which TWO statements correctly describe the configuration and verification of IPv4 and IPv6 parameters for host connectivity?

Accepted Answer

On a Windows host, the default gateway IPv4 address must be on the same subnet as the host's IPv4 address.. For a host to reach outside its subnet, the default gateway's IP must be in the same subnet; otherwise the host cannot ARP for the gateway's MAC and traffic will fail. Option D is correct because DNS server addresses can be set manually or assigned via DHCP. Option B is wrong because IPv6 gateways must be on the same local link, not any global unicast address on the internet. Option C is wrong because the subnet mask defines the network/subnet portion of an IPv4 address, not the host portion. Option E is wrong because DNS is used for name resolution; local IP communication on the same subnet works without DNS.

Answer

The IPv6 default gateway can be any global unicast address on the internet.

Answer

The subnet mask is used to define the host portion of an IPv4 address.

Answer

Configuring a DNS server is mandatory for a host to communicate with any other device on the same subnet.

Question 4

A host receives a correct IP address and subnet mask from DHCP but still cannot reach remote networks. Local subnet communication works. Which missing DHCP option is the strongest suspect?

Accepted Answer

Default gateway information. The strongest suspect is the default gateway option. In practical terms, the host can already identify local destinations because the subnet mask is present. That is why local communication still works. What it does not have is the next hop needed for off-subnet traffic. Without a default gateway, remote communication usually fails.

This is a very common host-troubleshooting scenario. It separates basic local addressing from the additional information required for off-subnet reachability.

Answer

An STP root bridge ID

Answer

A voice VLAN value

Answer

A router ID

Question 5

An operations team wants a monitoring platform to periodically read interface counters and CPU statistics from routers. Which technology is most closely associated with that requirement?

Accepted Answer

SNMP. SNMP is the best fit for that requirement. In practical terms, periodic reading of counters and statistics is polling-style monitoring, which is one of the classic SNMP use cases. A management system can query devices for interface status, utilization data, and other measurable values over time.

This is different from Syslog, which is event-message oriented, and from NetFlow, which focuses on traffic-flow visibility rather than general device statistics. The question is really about routine monitoring and polling.

Answer

Syslog

Answer

NetFlow

Answer

Port security

Question 6

A host address is 192.168.1.14/29. Which address is the broadcast address for that host’s subnet?

Accepted Answer

192.168.1.15. A /29 uses blocks of 8 addresses. In plain language, the subnets in the last octet move in increments of 8: 0–7, 8–15, 16–23, and so on. Since the host address ends in 14, it belongs to the 8–15 block. In that block, the last address is the broadcast address, so the broadcast is 192.168.1.15.

This is a classic subnetting pattern because it requires you to place the host inside the correct block and then identify the last address in that block rather than guessing based on the host value itself.

Answer

192.168.1.7

Answer

192.168.1.14

Answer

192.168.1.16

Question 7

An administrator needs to configure an ACL to block HTTP traffic from subnet 10.10.10.0/24 to the web server at 172.16.1.10 while permitting all other traffic. Which ACL entry should be placed first?

Accepted Answer

deny tcp 10.10.10.0 0.0.0.255 host 172.16.1.10 eq 80. The ACL needs a narrow deny statement that matches only TCP port 80 from the specified source subnet to the specific server. In practical terms, the requirement is not to block all IP traffic or all access to the host. It is to stop normal HTTP while allowing everything else. That means the entry must be precise.

This is the kind of ACL question the CCNA exam likes because it forces you to distinguish protocol, destination, and service rather than relying on vague source-only logic.

Answer

deny ip 10.10.10.0 0.0.0.255 host 172.16.1.10

Answer

permit tcp 10.10.10.0 0.0.0.255 host 172.16.1.10 eq 80

Answer

deny udp 10.10.10.0 0.0.0.255 host 172.16.1.10 eq 80

Question 8

A host receives its IP address automatically but cannot resolve hostnames. Which additional service information is most likely missing from its configuration?

Accepted Answer

A DNS server address. If the host receives an IP address but cannot resolve hostnames, the most likely missing information is a DNS server setting. In plain language, the device has enough configuration to join the network but not enough to ask where hostnames map in IP terms. DHCP can provide this DNS server information automatically, and if it is missing, the host may still communicate by IP while failing on names.

This is a common service-troubleshooting pattern because it separates address configuration from name resolution. The correct answer is the missing DNS-related setting rather than the IP address itself or the subnet mask.

Answer

A new MAC address

Answer

A trunk native VLAN

Answer

An OSPF router ID

Question 9

Exhibit: A user reports intermittent connectivity after a new switch was connected to an access port. Which feature would have prevented this by immediately disabling the port when a BPDU was received?

Accepted Answer

BPDU Guard. BPDU Guard is the correct answer because it protects PortFast-enabled edge ports by immediately disabling the port upon receiving a BPDU, preventing accidental loops. Root Guard prevents the port from becoming a root port, not from BPDU reception. Loop Guard prevents alternate or root ports from becoming designated due to BPDU loss, unrelated to BPDU reception disabling. UDLD detects unidirectional links but does not disable ports upon BPDU reception.

Answer

Root Guard

Answer

Loop Guard

Answer

UDLD

Question 10

A router learns the same destination prefix from OSPF and EIGRP. The prefix length is identical, and both routes are valid. Which route is preferred by default?

Accepted Answer

The EIGRP route. The EIGRP route is preferred by default because EIGRP has a lower default administrative distance than OSPF. In practical terms, once the prefix length is the same, the router compares source trust. Lower administrative distance wins. EIGRP’s default of 90 beats OSPF’s default of 110.

This is not a longest-prefix question. The prefix is identical, so the decision is about source preference rather than specificity.

Answer

The OSPF route

Answer

Both routes are installed equally because the prefix length matches

Answer

Neither route is used because protocols cannot advertise the same prefix

Question 11

An enterprise network uses an IPv6 dual-stack design. Router R1 has a primary default route ::/0 via 2001:db8:1::1 with AD 1 and a floating default route with AD 10 via link-local address fe80::2. After the primary link fails, the floating route fails to install, and R1 loses all external connectivity. The administrator confirms the backup interface is up/up.

Accepted Answer

The floating static route uses a link-local next-hop but does not specify an exit interface, making the route incomplete.. A floating static route using a link-local next-hop (fe80::2) must also specify an exit interface (e.g., GigabitEthernet0/1) to be considered complete. Without the exit interface, the router cannot determine which interface to use for neighbor discovery, leaving the route incomplete and unable to be installed into the routing table. This is a common requirement for IPv6 static routes with link-local addresses, as the next-hop is not globally unique.

Answer

The administrative distance of the backup route is 10, so it is not installed while the primary route still exists.

Answer

The floating static route will be installed only if the primary link is administratively shut down, not after a physical failure.

Answer

The next-hop fe80::2 is unreachable because IPv6 neighbor discovery is disabled on the backup interface.

Question 12

Which TWO actions does DHCP snooping perform by default on a Cisco switch?

Accepted Answer

It blocks DHCP server messages received on untrusted ports.. DHCP snooping is a security feature that, by default, filters DHCP server messages (such as DHCPOFFER, DHCPACK, and DHCPNAK) received on untrusted ports. This prevents rogue DHCP servers from offering malicious IP configurations to clients. The switch also automatically builds and maintains a DHCP snooping binding table, which maps client MAC addresses to leased IP addresses, VLANs, and port information, to validate DHCP traffic.

Answer

It generates a Cisco Discovery Protocol packet for each DHCP request.

Answer

It relays DHCP requests across VLANs.

Answer

It converts DHCP broadcasts into unicasts.

Question 13

R1 and R2 should form an OSPF adjacency on their shared GigabitEthernet link, but they remain stuck in EXSTART. What is the most likely cause?

Accepted Answer

The interface MTU values do not match.. The MTU values do not match. OSPF neighbors can discover each other and even move through earlier states, but an MTU mismatch commonly leaves them stuck in EXSTART or EXCHANGE because the routers do not agree on database description packet sizing. Area mismatch, network mismatch, and passive-interface issues usually prevent a much earlier stage of adjacency formation.

Answer

The routers are using different OSPF areas.

Answer

One side is configured as passive-interface.

Answer

The subnet mask on the link is incorrect.

Question 14

A controller-based WLAN is deployed across multiple floors. Users can associate to the SSID on both floors, but their experience improves when moving between APs compared with a poorly designed standalone deployment. Which wireless concept is most closely related to that client movement experience?

Accepted Answer

Roaming between access points. The concept most closely related is roaming between access points. In practical terms, client mobility experience depends on how smoothly a device can move from one AP coverage area to another while staying on the WLAN. Controller-based designs often help manage this more consistently than fragmented independent configurations.

The key point is that the question is about movement between APs while remaining on the wireless network, not about VLAN trunks or routing protocol neighbors.

Answer

NetFlow export

Answer

DHCP snooping

Answer

Route summarization

Question 15

A network administrator is troubleshooting connectivity issues between two switches. Hosts connected to Switch A cannot ping hosts on Switch B. The link between the switches shows as up/up on both ends, but interface error counters (CRC, runts) are increasing rapidly. What should the administrator do to resolve the issue?

Accepted Answer

Change the duplex setting on SwitchA's interface to auto-negotiation.. The increasing CRC and runts errors on an up/up link indicate a duplex mismatch, where one side is using full duplex and the other half duplex. Assuming SwitchB is using auto-negotiation (the default on Cisco switches), changing SwitchA's interface to auto-negotiation will allow both ends to negotiate the correct duplex setting, resolving the mismatch and stopping the errors.

Answer

Replace the faulty cable between the two switches.

Answer

Replace the SFP module on SwitchA's GigabitEthernet0/1 port.

Answer

Enable the interface with 'no shutdown' command.