CCNA Network Infrastructure and Connectivity Practice Test 17 — 15 Questions

Question 1

Drag and drop the following steps into the correct order to isolate and resolve interface CRC errors, duplex mismatches, and flapping on a Cisco IOS-XE switch.

Accepted Answer

Check interface statistics for CRC errors, runts, or giants; verify duplex and speed settings; replace faulty cables or transceivers; monitor interface to confirm resolution.. Start with checking statistics to identify issues, then verify duplex and cable, replace hardware if needed, and finally confirm resolution.

Answer

Replace the cable immediately; then check interface statistics; if errors persist, adjust duplex settings; finally, monitor the interface.

Answer

Verify duplex and speed settings; then replace the cable; check interface statistics; finally, monitor the interface.

Answer

Monitor the interface for errors; then replace the cable; if errors continue, adjust duplex settings; finally, check interface statistics.

Question 2

Drag and drop the following troubleshooting steps into the correct order to isolate CRC errors, duplex mismatches, and flapping on a Cisco IOS-XE interface.

Accepted Answer

Use show commands to gather interface statistics and identify errors.. First, gather data with show commands to identify the errors (CRC, duplex, flapping). Then apply configuration changes to resolve the issue. Next, clear interface counters to reset statistics and create a clean baseline. Finally, monitor interface statistics to verify that the errors are no longer occurring.

Question 3

Drag and drop the following steps into the correct order to troubleshoot a suspected duplex mismatch and CRC errors on a Cisco switch interface using CLI commands.

Accepted Answer

1. Use 'show interfaces' to check for CRC errors and duplex mismatch. 2. Manually set speed and duplex on both ends to match. 3. Use 'clear counters' to reset interface statistics. 4. Use 'show interfaces' again to verify no new errors.. Start by examining current interface stats, then fix the mismatch, and finally clear and recheck counters.

Answer

1. Use 'clear counters' to reset interface statistics. 2. Use 'show interfaces' to check for CRC errors. 3. Manually set speed and duplex on both ends to match. 4. Use 'show interfaces' again to verify no new errors.

Answer

1. Use 'show interfaces' to check for CRC errors. 2. Use 'clear counters' to reset interface statistics. 3. Manually set speed and duplex on both ends to match. 4. Use 'show interfaces' again to verify no new errors.

Answer

1. Manually set speed and duplex on both ends to match. 2. Use 'show interfaces' to check for CRC errors. 3. Use 'clear counters' to reset interface statistics. 4. Use 'show interfaces' again to verify no new errors.

Question 4

Drag and drop the following steps into the correct order to troubleshoot a suspected duplex mismatch and CRC errors on an interface using Cisco IOS-XE CLI commands.

Accepted Answer

1. Connect to the device via console or SSH
2. Enter privileged EXEC mode
3. Enter global configuration mode
4. Use 'interface' command to enter the specific interface
5. Use 'duplex full' to set duplex manually
6. Use 'speed 100' to set speed manually
7. Use 'end' to exit configuration mode
8. Use 'show interfaces' to check for CRC errors and duplex mismatch
9. Use 'copy running-config startup-config' to save. First, access the device and enter privileged mode, then run 'show interfaces' to diagnose CRC errors and confirm a duplex mismatch. Next, enter configuration mode and set the speed manually before duplex; setting speed first prevents the duplex from reverting to auto. Finally, exit configuration mode and save the running config to ensure the change persists.

Answer

1. Connect to the device via console or SSH
2. Enter privileged EXEC mode
3. Use 'show interfaces' to check for CRC errors and duplex mismatch
4. Enter global configuration mode
5. Use 'interface' command to enter the specific interface
6. Use 'duplex full' to set duplex manually
7. Use 'speed 100' to set speed manually
8. Use 'end' to exit configuration mode
9. Use 'copy running-config startup-config' to save

Question 5

Drag and drop the following steps into the correct order to troubleshoot a suspected duplex mismatch and CRC errors on a Cisco switch interface.

Accepted Answer

Enter privileged EXEC mode using the 'enable' command.. Troubleshooting starts from privileged EXEC, checking errors, identifying the problematic interface, then configuring the correct duplex setting.

Question 6

Which TWO interface error counters indicate a Layer 1 issue?

Accepted Answer

CRC errors. CRC errors occur when the cyclic redundancy check computed at the receiver does not match the value appended by the sender, indicating that the frame was corrupted during transmission. This corruption is typically caused by physical-layer problems such as faulty cabling, bad connectors, or excessive electrical noise. Runts are frames that are smaller than the minimum Ethernet frame size of 64 bytes (excluding preamble), and they often result from collisions or transceiver issues that are Layer 1 phenomena. Both counters directly point to physical-layer impairments rather than logical or congestion-related issues.

Answer

Output queue drops

Answer

Input errors

Answer

Ignored packets

Question 7

Drag and drop the following steps into the correct order to configure an IPv4 address on a Cisco IOS-XE router interface, then verify the configuration with a ping to a host that uses an IPv6 EUI-64 address.

Accepted Answer

Enter global configuration mode, enter interface configuration mode, assign IPv4 address, exit to enable mode, ping IPv6 host. The correct sequence is to first enter global configuration mode, then interface configuration mode, assign the IPv4 address, exit completely to enable mode, and finally ping the IPv6 host. Option B is incorrect because you cannot enter interface configuration mode before global configuration mode; you must be in global config first. Option C is incorrect because you cannot assign an IPv4 address in global configuration mode; that command must be issued in interface configuration mode. Option D is incorrect because you cannot execute the ping command from interface configuration mode; you must exit to enable mode first.

Question 8

Drag and drop the following steps into the correct order to configure an IPv4 static address on a Windows host, generate an IPv6 EUI-64 address on a Cisco router, verify the router's IPv6 EUI-64 address, and confirm connectivity from the Windows host.

Accepted Answer

Set static IPv4 address on Windows host. The correct order is: first configure the router's IPv6 EUI-64 address to set up the network infrastructure, then assign the Windows host a static IPv4 address. Next, verify the router's IPv6 EUI-64 address to confirm proper generation. Finally, perform a connectivity test from the Windows host to validate end-to-end communication. This sequence ensures that configuration is completed before verification and that the final step confirms both configurations are operational.

Question 9

Drag and drop the steps into the correct order to generate an IPv6 EUI-64 address from a MAC address.

Accepted Answer

Obtain the MAC address of the host interface.. Start by obtaining the MAC address and splitting it into two 24‑bit halves (OUI and NIC portions). Insert FFFE in the middle to create a 64‑bit interface identifier. Flip the U/L bit (7th bit) of the first byte, then combine the identifier with the IPv6 prefix (e.g., FE80::/10 for link‑local) to form the complete address.

Question 10

Drag and drop the following steps into the correct order to configure an IPv4 static address on a Windows host, generate an IPv6 EUI-64 address on a Cisco router, and verify the static IP assignment on Windows.

Accepted Answer

Configure static IPv4 address on Windows → Generate IPv6 EUI-64 address on router → Verify static IP on Windows. The static IPv4 is configured on Windows first, then the EUI-64 IPv6 address on the router, and finally verification on Windows. This order separates host and router tasks logically.

Answer

Generate IPv6 EUI-64 address on router → Configure static IPv4 address on Windows → Verify static IP on Windows

Answer

Configure static IPv4 address on Windows → Verify static IP on Windows → Generate IPv6 EUI-64 address on router

Answer

Generate IPv6 EUI-64 address on router → Verify static IP on Windows → Configure static IPv4 address on Windows

Question 11

Which TWO of the following are essential IPv4 host parameters that must be correctly configured for a host to communicate with devices on remote networks?

Accepted Answer

Default gateway. The default gateway is the IP address of the router interface on the local subnet; when a host needs to communicate with a device on a remote network, it must forward packets to the default gateway because the destination is not reachable locally. The subnet mask is equally essential because the host uses it (along with its own IP address) to determine whether a destination IP address is on the same local network or a remote network; without a correctly configured subnet mask, the host cannot make this determination and may misroute traffic. DNS server address is only for name resolution and is not required for IP-level connectivity, MAC address is a Layer 2 address already present on the NIC, and hostname is a local identifier irrelevant to routing.

Answer

DNS server address

Answer

MAC address

Answer

Host name

Question 12

Drag and drop the IPv6 address types on the left to their corresponding scope and prefix on the right.

Accepted Answer

Global Unicast: 2000::/3, Internet scope. IPv6 address types have defined scopes and prefixes: Global Unicast has global scope with 2000::/3, Link-Local has link-local scope with FE80::/10, Unique Local has unique local scope with FC00::/7, Multicast has multicast scope with FF00::/8, Loopback has loopback scope with ::1/128, and Unspecified has unspecified scope with ::/128. Each address type's description should explicitly state its scope to clarify the matching task.

Answer

FE80::/10; link-local scope, automatically assigned on each interface

Answer

FC00::/7; unique local scope, private, not routable on the Internet

Answer

FF00::/8; multicast scope, one-to-many communication

Question 13

Drag and drop the following steps into the correct order to configure a WLAN for WPA3-Enterprise on a Cisco WLC and sequence a wireless client association process.

Accepted Answer

Create WLAN with WPA3-Enterprise security, enable WLAN, client associates, 802.1X authentication, DHCP IP assignment. The configuration creates the WLAN with WPA3-Enterprise security, enables it, then the client associates and completes 802.1X authentication before getting an IP.

Answer

Create WLAN with WPA3-Enterprise security, enable WLAN, client associates, DHCP IP assignment, 802.1X authentication

Answer

Enable WLAN, create WLAN with WPA3-Enterprise security, client associates, 802.1X authentication, DHCP IP assignment

Answer

Create WLAN with WPA3-Enterprise security, client associates, enable WLAN, 802.1X authentication, DHCP IP assignment

Question 14

Drag and drop the following steps into the correct order to configure a WPA3 SSID on a Cisco WLC and complete a wireless client association.

Accepted Answer

Create a new WLAN with SSID and WPA3-Personal security, enable the WLAN, then the client scans, associates, and obtains an IP via DHCP.. The steps follow the standard WLC configuration sequence: create the WLAN, set WPA3-Personal security, enable it, then the client associates and gets an IP.

Answer

Enable the WLAN first, then create the WLAN with SSID and WPA3-Personal security, then the client associates and obtains an IP.

Answer

Create the WLAN, enable it, then configure WPA3-Personal security, then the client associates and gets an IP.

Answer

Create the WLAN, configure WPA3-Personal security, enable the WLAN, then the client obtains an IP before associating.

Question 15

Drag and drop the following steps into the correct order to configure an SSID on a WLC and complete a WPA3-Personal client association with DHCP address assignment.

Accepted Answer

Configure DHCP scope, create an SSID profile, enable the SSID, configure WPA3-Personal security, client associates and obtains IP address.. The correct sequence is to first create the SSID profile, then configure WPA3-Personal security to ensure the WLAN is protected before it becomes active, then enable the SSID, set up the DHCP scope for address assignment, and finally allow the client to associate and obtain an IP address. Option A enables the SSID before setting security, exposing the network to unauthorized access during that window. Option B incorrectly starts with DHCP configuration before the SSID even exists. Option D also enables the SSID before security, leading to the same vulnerability as option A. Only option C follows the secure configuration order recommended by Cisco.

Answer

Create an SSID profile, enable the SSID, configure WPA3-Personal security, configure DHCP scope, client associates and obtains IP address.