CCNA Practice Test 43 — 15 Questions

Question 1

You are connected to R1. The network consists of R1, SW1, and two hosts (Host-A on VLAN 10, Host-B on VLAN 20). SW1 has two access ports (one per VLAN) and a trunk to R1. Configure R1 for router-on-a-stick inter-VLAN routing. The current configuration has a native VLAN mismatch and a missing subinterface for VLAN 20. Fix these issues so that Host-A and Host-B can ping each other.

Accepted Answer

Configure interface G0/0.20 with encapsulation dot1Q 20 and IP address 192.168.20.1 255.255.255.0, set native VLAN to 1 on the trunk, and enable ip routing.. The native VLAN mismatch exists: R1 expects native VLAN 99, but SW1 likely uses native VLAN 1 (default). This causes CDP/STP issues but not directly inter-VLAN routing; however, for proper operation, set native VLAN to 1 on R1. Additionally, the subinterface for VLAN 20 is missing, so traffic from VLAN 20 cannot be routed. Finally, 'ip routing' is disabled, preventing any inter-VLAN routing. Solution: change native VLAN on trunk to 1, create subinterface G0/0.20 with encapsulation dot1Q 20 and IP 192.168.20.1/24, and enable ip routing.

Answer

Configure interface G0/0.20 with encapsulation dot1Q 20 and IP address 192.168.20.1 255.255.255.0, set native VLAN to 99 on the trunk, and enable ip routing.

Answer

Configure interface G0/0.20 with encapsulation dot1Q 20 and IP address 192.168.20.1 255.255.255.0, set native VLAN to 1 on the trunk, but do not enable ip routing.

Answer

Configure interface G0/0.20 with encapsulation dot1Q 20 and IP address 192.168.20.1 255.255.255.0, set native VLAN to 99 on the trunk, and do not enable ip routing.

Question 2

An engineer is comparing data serialization formats used by controllers and automation tools. Which two statements correctly describe JSON?

Accepted Answer

It represents data as key-value pairs and arrays. JSON structures data using key-value pairs (objects) and ordered lists (arrays), which are fundamental to its syntax. Option B is correct as JSON is the standard payload format for REST API requests and responses due to its lightweight nature and ease of parsing. Option C is incorrect because JSON does not use closing tags; instead, it relies on curly braces {} for objects and square brackets [] for arrays. Option D is incorrect because JSON supports multiple data types beyond numeric values, including strings, booleans, null, arrays, and nested objects.

Answer

It requires closing tags like XML

Answer

It can only represent numeric values

Question 3

Which ACL type can filter using source and destination IP addresses as well as TCP or UDP port numbers?

Accepted Answer

Extended IPv4 ACL. Extended ACLs provide more granular matching, including source, destination, protocol, and Layer 4 port information.

Answer

Standard IPv4 ACL

Answer

Prefix list

Answer

Native VLAN ACL

Question 4

Which two statements correctly describe a RESTful API used by network controllers? Choose two.

Accepted Answer

It commonly uses HTTP methods such as GET and POST. REST commonly uses HTTP methods such as GET, POST, PUT, PATCH, and DELETE. It is also stateless, which means each request includes the information needed for the server to process it.

Answer

It requires SNMP traps for every successful request

Answer

It can only return XML, never JSON

Question 5

Why is multifactor authentication generally stronger than password-only access?

Accepted Answer

It relies on more than one authentication factor.. MFA combines independent factors, so compromise of one factor does not automatically grant access.

Answer

It removes the need for authorization policies.

Answer

It guarantees that credentials can never be phished.

Answer

It replaces encryption on the network.

Question 6

A network engineer queries a REST API and receives data in JSON format. Which statement about JSON is correct?

Accepted Answer

JSON stores data as key-value pairs and arrays. JSON is a lightweight data-interchange format that represents data as key-value pairs and arrays. Option A is incorrect because JSON is not a transport protocol; it is a data format exchanged over HTTPS. Option C is incorrect because JSON is platform-agnostic and used by many APIs, not limited to Cisco DNA Center. Option D is incorrect because JSON uses a flexible syntax with colons and brackets, not XML tags.

Answer

JSON is a transport protocol that replaces HTTPS

Answer

JSON can be used only with Cisco DNA Center

Answer

JSON requires XML tags around each object

Question 7

Exhibit: Users complain of slow wireless performance in a dense office even though signal strength is strong. Multiple APs are using channels 1, 2, and 3 on 2.4 GHz. Which change is most appropriate?

Accepted Answer

Move to non-overlapping channels such as 1, 6, and 11. In 2.4 GHz, overlapping channels cause co-channel and adjacent-channel interference. The common non-overlapping choices are 1, 6, and 11. Moving away from overlapping channels usually improves performance in a dense deployment.

Answer

Reduce all AP transmit power to zero

Answer

Change every AP to the same channel for consistency

Answer

Disable WPA2 security

Question 8

What data format is commonly used in REST API responses because it is lightweight and easy for applications to parse?

Accepted Answer

JSON. JSON is widely used in REST APIs for structured data exchange.

Answer

BGP

Answer

STP

Answer

ARP

Question 9

As a general rule, where should an extended ACL be placed?

Accepted Answer

As close to the source as practical. Extended ACLs are commonly placed near the source to stop unwanted traffic earlier and conserve bandwidth and device resources.

Answer

As close to the destination as possible in all cases

Answer

Only on the default gateway

Answer

Only on WAN interfaces

Question 10

A switch port connected to a user PC is configured as a trunk. The PC cannot communicate normally. What is the best explanation?

Accepted Answer

The port role is wrong because a normal PC-facing switchport should usually be an access port, not a trunk. The best explanation is that the port role is wrong: a PC-facing port should be an access port, not a trunk, because PCs normally send untagged frames and cannot process VLAN tags. Option B is incorrect because EtherChannel is used for link aggregation, not required for a single PC. Option C is wrong because trunk mode does not disable MAC address learning. Option D is irrelevant, as switches do not stop using IP addressing in trunk mode.

Answer

A user PC requires EtherChannel to function

Answer

Trunk mode disables MAC address learning automatically

Answer

Trunk mode forces the switch to stop using IP addressing

Question 11

Select the correct sequence of steps to retrieve a specific interface's configuration via RESTCONF and apply a change to the interface description.

Accepted Answer

Send GET request to retrieve interface configuration, parse JSON/XML response, modify the description field, send PUT request with updated configuration, send GET request to verify the change.. The correct sequence for using RESTCONF to modify an interface description is: first retrieve the current configuration with a GET request, parse the JSON or XML response, modify the description field, apply the change with a PUT or PATCH request, and finally verify the change with another GET request. This sequence is correctly described only in option A. Options B, C, and D are incorrect because they either apply changes before retrieving the configuration, modify before retrieving, or verify before applying, which would not work as intended.

Answer

Send PUT request to apply the change, send GET request to retrieve interface configuration, parse JSON/XML response, modify the description field, send GET request to verify the change.

Answer

Send GET request to retrieve interface configuration, modify the description field, send GET request to verify the change, send PUT request with updated configuration.

Answer

Send PUT request with updated configuration, send GET request to retrieve interface configuration, parse JSON/XML response, modify the description field, send GET request to verify the change.

Question 12

Which two statements accurately describe good design thinking for wireless guest access?

Accepted Answer

Guest access should normally be isolated from internal corporate resources.. Good guest-access design is based on isolation and appropriate policy. In practical terms, guest users should normally be separated from internal corporate resources, and their access should align with the limited purpose of guest connectivity. The goal is not to give them the same trust level as managed internal users.

This is about segmentation and policy, not about disabling the WLAN or eliminating security.

Answer

Guest WLANs should avoid all security to make access easier.

Answer

Guest WLANs should automatically use the same permissions as internal employee WLANs.

Answer

Guest access means the AP no longer needs controller coordination.

Question 13

You are troubleshooting a wireless client connectivity issue on the Cisco WLC at 192.168.1.100. The client reports it can see the SSID 'CorpNet' and successfully associates, but cannot obtain an IP address or reach network resources. The WLAN is already configured with WPA3 security, and the SSID should remain hidden. Identify and correct the configuration issue.

Accepted Answer

The WLAN is mapped to the management interface. Use 'config wlan interface 1 CorpNet_VLAN' to assign the correct interface.. The WLAN is incorrectly mapped to the management interface, which places client traffic in the management VLAN instead of the correct CorpNet_VLAN. As a result, clients cannot obtain IP addresses or communicate beyond the WLC. Reassigning the WLAN to the CorpNet_VLAN interface with 'config wlan interface 1 CorpNet_VLAN' resolves the issue by placing client data in the proper VLAN.

Answer

The SSID is not hidden. Use 'config wlan disable-broadcast-ssid 1 enable' to hide the SSID.

Answer

WPA3 is not enabled on the WLAN. Use 'config wlan security wpa akm 6 enable' to enable WPA3.

Answer

The WLAN is disabled. Use 'config wlan enable 1' to enable the WLAN.

Question 14

Which switch security feature uses DHCP snooping bindings to validate ARP packets and help stop ARP spoofing?

Accepted Answer

Dynamic ARP Inspection. Dynamic ARP Inspection compares ARP information to trusted bindings, often learned through DHCP snooping, to block forged ARP packets.

Answer

PortFast

Answer

UDLD

Answer

HSRP preemption

Question 15

A host address is 172.22.14.99/27. Which address is the broadcast address of the subnet?

Accepted Answer

172.22.14.127. A /27 subnet has a block size of 32. In practical terms, the relevant blocks are 0-31, 32-63, 64-95, 96-127, and so on. Because 99 falls within the 96-127 block, the broadcast address is the last address in that block: 172.22.14.127.

This is a classic subnet-boundary question and remains important because addressing precision appears throughout the CCNA blueprint.

Answer

172.22.14.95

Answer

172.22.14.96

Answer

172.22.14.128