CCNA Mock Exam 92 — 25 Questions

Question 1

Match each IPv4 addressing term to its most accurate meaning.

Accepted Answer

Host address. The network address is the first address in a subnet and identifies the subnet itself. The host address is any usable address assigned to a device within the subnet. The broadcast address is the last address in the subnet, used to send data to all hosts. The subnet mask is a 32-bit value that separates the network and host portions of an IP address.

Answer

Network address

Answer

Broadcast address

Answer

Loopback address

Question 2

Why is a default route often called a route of last resort?

Accepted Answer

Because it is used only when no more specific route matches the destination.. Option A correctly identifies the default route as a route of last resort because it is used only when no more specific route matches the destination. Option B is incorrect because bandwidth is not a defining characteristic of a default route; it is simply a fallback path. Option C is wrong because default routes can be configured statically or learned via any routing protocol (e.g., OSPF, EIGRP, RIP), not exclusively OSPF. Option D is false because the default route is the least specific route (0.0.0.0/0), not more specific than any other route.

Answer

Because it always has the lowest bandwidth.

Answer

Because it must be learned from OSPF only.

Answer

Because it is more specific than every other route.

Question 3

Which two statements accurately describe basic WLAN security at the CCNA level?

Accepted Answer

WPA2 is generally considered stronger than WEP for wireless security.. WPA2 uses AES-CCMP encryption and is much stronger than WEP, which uses weak RC4. Open wireless networks (no security) provide no encryption, so they are less secure than a secured WLAN. Option B is false because open networks have no default encryption. Option D is false because SSID length does not affect WEP's cryptographic strength; WEP is inherently weak regardless of SSID. Option E is false because WPA2 is a security protocol, not a duplex mode.

Answer

Open wireless access provides meaningful default encryption.

Answer

A longer SSID makes WEP cryptographically strong.

Answer

WPA2 relies on TKIP encryption

Question 4

Match each wireless concept to its most accurate description.

Accepted Answer

SSID is the network name, BSSID is the AP's MAC, beacon frames advertise the network, probe requests are client discovery, association is joining the network, and authentication verifies identity before association.. SSID is the WLAN name broadcasted to clients, making it synonymous with 'The WLAN name shown to clients.' An access point is the device that bridges wireless clients to the wired network, directly matching 'Device that provides wireless connectivity.' A controller-based WLAN uses a central controller to manage multiple APs, which aligns with 'Design in which centralized devices manage APs.' WPA2 is a security protocol for wireless networks, fitting 'Wireless security standard.' The other concepts (BSSID, beacon frames, etc.) are related but not part of this matching exercise.

Answer

SSID is the AP's MAC, BSSID is the network name, beacon frames are used for client discovery, probe requests advertise the network, association verifies identity, and authentication joins the network.

Answer

SSID is the network name, BSSID is the AP's MAC, beacon frames are used for client discovery, probe requests advertise the network, association verifies identity, and authentication joins the network.

Answer

SSID is the AP's MAC, BSSID is the network name, beacon frames advertise the network, probe requests are client discovery, association verifies identity, and authentication joins the network.

Question 5

Which three of the following are characteristics of Layer 2 Ethernet switches that improve network performance? (Choose three.)

Accepted Answer

They can perform cut-through switching to reduce latency.. Layer 2 Ethernet switches improve network performance by creating separate collision domains per port, eliminating collisions between devices on different ports. They forward frames based on the destination MAC address, enabling efficient hardware-based switching. Cut-through switching reduces latency by starting to forward as soon as the destination MAC address is read. The other options are incorrect: switches do not reduce broadcast domains (broadcasts are forwarded to all ports in the same VLAN unless a router or VLAN segmentation is used); switches operate at Layer 2 using MAC addresses, not IP addresses; and unknown unicast frames are flooded out all ports except the incoming port, not automatically blocked, to ensure connectivity if the destination is unknown.

Answer

They use IP addresses to make forwarding decisions.

Answer

They reduce the number of broadcast domains.

Answer

They automatically block all unknown unicast frames.

Question 6

Drag and drop the following troubleshooting steps into the correct order to diagnose a client connectivity issue using the OSI bottom-up method. The client is unable to access a web server by its FQDN.

Accepted Answer

Check physical connectivity, then verify link status, then check IP configuration, then test DNS resolution, then attempt HTTP access.. The OSI bottom-up approach starts at Layer 1 (physical), then Layer 2 (data link), Layer 3 (network), and finally Layer 7 (application) for DNS/FQDN resolution. The given sequence follows this principle by checking physical connectivity and link status before IP configuration, then testing DNS and HTTP access.

Question 7

Which two statements correctly describe syslog severity levels?

Accepted Answer

Level 0 is the most severe. Syslog uses numbered severity levels where lower numbers indicate more critical events. Level 0 (Emergency) is the most severe, and Level 7 (Debugging) is the least. Option D is incorrect because severity levels are a syslog function, not specific to NTP. Option E is wrong because syslog defines eight severity levels (0–7), not four.

Answer

Higher numbers always mean more critical issues

Answer

Severity levels are used only by NTP

Answer

Syslog has only four severity levels

Question 8

Which OSI layer is responsible for end-to-end segmentation, port numbers, and reliability functions such as acknowledgments?

Accepted Answer

Transport. The Transport layer (Layer 4) is responsible for end-to-end segmentation, port numbers for identifying applications, and reliability functions like acknowledgments and retransmission. The Network layer (Layer 3) handles logical addressing and routing between networks. The Data Link layer (Layer 2) manages local frame delivery and error detection. The Session layer (Layer 5) controls dialog management and synchronization, not segmentation or ports.

Answer

Network

Answer

Data Link

Answer

Session

Question 9

Which TWO statements correctly describe the configuration and verification of OSPFv3 for IPv6?

Accepted Answer

OSPFv3 uses link-local IPv6 addresses to form neighbor adjacencies.. OSPFv3 for IPv6 uses link-local IPv6 addresses (FE80::/10) to form neighbor adjacencies, not global unicast addresses (so B is incorrect). OSPFv3 does not automatically enable on all IPv6 interfaces; each interface must be explicitly configured under the OSPFv3 process using the 'ipv6 ospf' command (so C is incorrect). The 'show ospfv3 neighbor' command displays the neighbor's Router ID (a 32-bit value), not the IPv6 address of the neighbor's interface (so E is incorrect). Correct options A and D accurately describe OSPFv3 neighbor formation using link-local addresses and the information shown by the 'show ospfv3 neighbor' command, which includes neighbor state, neighbor ID, and interface.

Answer

OSPFv3 uses global unicast IPv6 addresses to form neighbor adjacencies.

Answer

OSPFv3 is automatically enabled on all IPv6-enabled interfaces when the routing process is configured.

Answer

The 'show ospfv3 neighbor' command displays the IPv6 address of the neighbor's interface as the neighbor ID.

Question 10

A network administrator is troubleshooting connectivity loss in a switched network. All switches run Rapid PVST+. A host connected to an access port on SwitchC can no longer reach the default gateway. The access port is configured with PortFast and BPDU Guard. The administrator checks the interface status and finds it in an err-disabled state. What is the most likely cause of this issue?

Accepted Answer

BPDU Guard detected a BPDU on a PortFast-enabled port and disabled it.. B is correct because BPDU Guard is designed to protect the spanning-tree topology by disabling a PortFast-enabled port if it receives a BPDU, placing the port in err-disabled state. Option A is incorrect: a root bridge election failure would not cause a port to err-disable; loops do not directly trigger this state without BPDU Guard. Option C is incorrect because PortFast and BPDU Guard work with all spanning-tree variants including Rapid PVST+. Option D is incorrect: a trunk misconfiguration alone would not cause err-disable unless BPDU Guard detects a BPDU on a PortFast port.

Answer

The root bridge election failed, causing a loop.

Answer

Rapid PVST+ is not compatible with PortFast.

Answer

The port is configured as a trunk but should be an access port.

Question 11

Which TWO statements accurately describe OSPFv3 configuration and verification for IPv6?

Accepted Answer

OSPFv3 uses IPv6 link-local addresses for neighbor discovery and next-hop addresses.. Option A is correct because OSPFv3 uses IPv6 link-local addresses for neighbor discovery and next-hop addresses. Option C is correct because the 'ipv6 ospf area ' interface command enables OSPFv3 on that interface. Option B is incorrect: OSPFv3 does not use the 'network' command; instead, it relies on interface-level configuration. Option D is incorrect: 'ipv6 router ospf ' is a global configuration command to enter OSPFv3 router configuration mode, not an interface command. Option E is incorrect: 'show ipv6 ospf neighbor' displays neighbor adjacencies, not the link-state database; use 'show ipv6 ospf database' for that.

Answer

The 'network' command under 'ipv6 router ospf' is used to advertise subnets into OSPFv3.

Answer

The 'ipv6 router ospf <process-id>' command is used on an interface to enable OSPFv3.

Answer

The 'show ipv6 ospf neighbor' command displays the OSPFv3 link-state database.

Question 12

An IPv6 host successfully reaches neighbors on its local segment, but it cannot reach remote IPv6 destinations. The host has a global unicast address and a correct prefix length. Which missing item is the strongest suspect?

Accepted Answer

A usable default router or next-hop route for off-link IPv6 traffic. The strongest suspect is the absence of a usable default router learned through IPv6 router advertisements or equivalent configuration. While local connectivity works because the host can communicate on its own link, remote IPv6 destinations require a next hop off the local segment. Option B is wrong because IPv6-to-IPv4 NAT is unnecessary for native IPv6 communication and would not be the primary cause of off-link failure. Option C is wrong because a VLAN trunk on the host NIC is for carrying multiple VLANs, not for enabling off-link routing. Option D is wrong because a second global unicast address does not provide a default route; it only adds another local address.

Answer

A NAT rule translating IPv6 to IPv4

Answer

A VLAN trunk on the host NIC

Answer

A second global unicast address on the same interface

Question 13

You are connected to R1. Configure HSRP so that R1 becomes the active router for VLAN 10, with a virtual IP of 192.168.10.1. Ensure that R1 preempts if it comes back online after a failure. Also, configure R1 to decrement its HSRP priority by 20 if its GigabitEthernet0/1 interface goes down. The current configuration shows both routers as active — identify and fix the issues.

Accepted Answer

Change the virtual IP to 192.168.10.1, set priority to 110, enable preempt, and track interface GigabitEthernet0/1 with decrement 20.. The scenario indicates both routers appear as Active, which is abnormal. This could result from a misconfigured virtual IP or group number mismatch. The required fix is to set the virtual IP to 192.168.10.1, assign R1 a higher priority (110 vs R2's default 100), enable preempt so R1 reclaims active role after failure, and track GigabitEthernet0/1 with a decrement of 20 to lower priority if that interface goes down.

Answer

Change the virtual IP to 192.168.10.1, set priority to 100, enable preempt, and track interface GigabitEthernet0/1 with decrement 20.

Answer

Change the virtual IP to 192.168.10.254, set priority to 110, enable preempt, and track interface GigabitEthernet0/1 with decrement 20.

Answer

Change the virtual IP to 192.168.10.1, set priority to 110, enable preempt, but do not track any interface.

Question 14

R1 and R2 are directly connected and running OSPF. They can ping each other, the area matches, and the timers match, but they still do not become neighbors. What is the most likely cause?

Accepted Answer

The OSPF authentication keys do not match.. The most likely cause is a mismatch in OSPF authentication keys. Even though the routers have IP connectivity, matching area IDs, and identical timers, OSPF adjacency requires that authentication parameters also match. If authentication is enabled on both sides but the keys differ, OSPF packets are silently rejected, preventing neighbor formation.

Answer

The subnet mask is too small for OSPF to operate.

Answer

The routers must use different process IDs.

Answer

The interfaces must be configured as switch trunks.

Question 15

Which TWO statements correctly describe how a router selects the best path for a destination network when multiple routing table entries exist?

Accepted Answer

Routes with the longest prefix length (most specific) are preferred over routes with a shorter prefix.. Routers select the best path by first applying the longest prefix match rule (most specific subnet mask), so option A is correct. If two routes have the same prefix length, the router then compares administrative distance (AD) and prefers the lower AD; option B is incorrect because it says higher AD is selected. When AD is equal, the router uses metric and chooses the lowest metric, making option C correct. Option D is false because directly connected routes have an AD of 0, not 1, and they are indeed more trustworthy than dynamic routes but not due to AD 1. Option E is wrong because directly connected routes are always preferred over dynamic routes regardless of adaptability.

Answer

If two routes have the same prefix length, the route with the higher administrative distance is selected.

Answer

A directly connected route has an administrative distance of 1, making it more trustworthy than any dynamic route.

Answer

Dynamic routes are always preferred over directly connected routes because they can adapt to network changes.

Question 16

A host can reach local devices but cannot reach the Internet. The host has a correct IP address and subnet mask, but no default gateway. What is the best explanation?

Accepted Answer

The host can reach only local subnet destinations because it lacks a next hop for remote networks. The host can communicate only within its own local subnet because it lacks the next-hop information needed for off-subnet traffic. A valid IP address and subnet mask are not enough by themselves when the destination lies on another network. Option D is incorrect because proxy ARP, while it may allow some off-subnet reachability in specific scenarios, is not a reliable replacement for a default gateway and does not enable general Internet access.

Answer

The host automatically uses ARP to reach all Internet destinations directly

Answer

The subnet mask alone should be enough to reach all networks

Answer

The host can still reach Internet destinations if proxy ARP is enabled on the router.

Question 17

Which two statements accurately describe OSPF route selection or behavior at the CCNA level?

Accepted Answer

OSPF uses cost as its metric for choosing paths within OSPF.. OSPF uses cost as its metric for path selection within the protocol, and OSPF routes are compared against other route sources using administrative distance when cross-protocol decisions are needed. OSPF supports equal-cost multi-path (ECMP), meaning it can install multiple equal-cost paths to the same destination, so option E is incorrect. The wrong answers confuse cost with administrative distance, treat process IDs as globally significant, or incorrectly direct cross-protocol metric comparisons.

Answer

OSPF compares its metric directly against EIGRP metrics across protocols.

Answer

OSPF process IDs must match between all neighboring routers.

Answer

OSPF can never install equal-cost paths.

Question 18

Drag and drop the following steps into the correct order to replace a faulty fiber optic SFP module and verify the interface on a Cisco IOS-XE switch. Assume the fiber cable is already disconnected from the SFP module.

Accepted Answer

Remove the old SFP module, insert the new SFP module, connect the fiber cable, verify interface status with 'show interfaces', and check for errors with 'show interfaces counters errors'.. The correct order assumes the fiber cable is already disconnected as a safety prerequisite. After removal of the old SFP, insert the new SFP, then reconnect the fiber cable. Finally, verify the interface status with 'show interfaces' and check for errors with 'show interfaces counters errors' to ensure proper operation.

Question 19

You are connected to SW1. A LACP EtherChannel between SW1 and SW2 has already been configured using interfaces GigabitEthernet0/1 and GigabitEthernet0/2 with channel-group 1 mode active on both sides and assigned to VLAN 100. However, the channel is not forming because of a speed/duplex mismatch. The correct interface settings for this network are speed 1000 and duplex full. Interface GigabitEthernet0/1 is already configured with these settings. Only interface GigabitEthernet0/2 needs to be corrected. Identify the configuration change needed to resolve the mismatch and verify the EtherChannel is up with 'show etherchannel summary'.

Accepted Answer

Configure interface GigabitEthernet0/2 with 'speed 1000' and 'duplex full', then verify the EtherChannel is up.. The EtherChannel is not forming because GigabitEthernet0/2 is configured with speed 100 and duplex half, while GigabitEthernet0/1 is speed 1000 and duplex full. LACP requires all member ports to have identical speed and duplex settings. To fix this, configure GigabitEthernet0/2 with speed 1000 and duplex full, matching GigabitEthernet0/1. After correction, the ports should bundle in Port-channel1 and show as bundled (P) in 'show etherchannel summary'.

Answer

Configure interface GigabitEthernet0/1 with 'speed 100' and 'duplex half', then verify the EtherChannel is up.

Answer

Configure interface GigabitEthernet0/2 with 'speed auto' and 'duplex auto', then verify the EtherChannel is up.

Answer

Configure interface GigabitEthernet0/2 with 'channel-group 1 mode active' and 'switchport access vlan 100', then verify the EtherChannel is up.

Question 20

Match each service or visibility technology to the most appropriate use case.

Accepted Answer

SNMP for device metrics, NetFlow for traffic analysis, Syslog for logs, IP SLA for performance measurement, Wireshark for packet analysis, Nmap for discovery and security.. Syslog collects device events and messages centrally, providing a centralized log repository. SNMP reads interface status and counters from devices, offering real-time device monitoring. NetFlow analyzes network traffic to identify bandwidth usage by host, making it ideal for finding top talkers. NTP synchronizes clocks across systems to maintain consistent event timelines. Each technology is matched to its primary use case.

Answer

SNMP for traffic analysis, NetFlow for device metrics, Syslog for performance measurement, IP SLA for logs, Wireshark for discovery and security, Nmap for packet analysis.

Answer

SNMP for logs, NetFlow for performance measurement, Syslog for device metrics, IP SLA for traffic analysis, Wireshark for discovery and security, Nmap for packet analysis.

Answer

SNMP for performance measurement, NetFlow for logs, Syslog for device metrics, IP SLA for traffic analysis, Wireshark for discovery and security, Nmap for packet analysis.