CCNA Network Infrastructure and Connectivity Practice Test 6 — 15 Questions

Question 1

You are connected to R1. Configure IPv4 and IPv6 addressing on R1's interfaces so that R1 can reach R2's loopback0 (192.0.2.1/32) and R2's IPv6 loopback0 (2001:db8:1::1/64). R1 has a misconfigured subnet mask on G0/0 and is missing its default gateway. Additionally, R1 has a duplicate IPv4 address on G0/1 that must be corrected. Use EUI-64 for R1's IPv6 link-local address on G0/0 and static IPv6 for the global unicast address on G0/1.

Accepted Answer

Change G0/0 mask to /30, add default route via 10.0.0.2, change G0/1 IP to 192.0.2.2/30, enable IPv6 on G0/0 with EUI-64 link-local, assign 2001:db8:2::1/64 to G0/1. Ly fixes the subnet mask on G0/0 to /30, adds the default gateway via 10.0.0.2, resolves the duplicate IP on G0/1 by assigning 192.0.2.2/30, and sets up IPv6 addressing as required (EUI-64 on G0/0 and static 2001:db8:2::1/64 on G0/1). However, for full IPv6 reachability to R2's loopback0 (2001:db8:1::1/64), R1 also needs an IPv6 route (e.g., a static route to 2001:db8:1::/64 via R2's link-local or global address on G0/1). Without this, Option A only ensures IPv4 connectivity but not IPv6. Among the given options, A is the best because it addresses all IPv4 issues and the IPv6 addressing requirements, though it is incomplete for IPv6 routing.

Answer

Change G0/0 mask to /24, add default route via 10.0.0.1, change G0/1 IP to 10.0.0.6/30, enable IPv6 on G0/0 with EUI-64 link-local, assign 2001:db8:1::1/64 to G0/1

Answer

Change G0/0 mask to /30, add default route via 10.0.0.1, change G0/1 IP to 192.0.2.2/30, enable IPv6 on G0/0 with EUI-64 link-local, assign 2001:db8:2::1/64 to G0/1

Answer

Change G0/0 mask to /30, add default route via 10.0.0.2, change G0/1 IP to 10.0.0.6/30, enable IPv6 on G0/0 with EUI-64 link-local, assign 2001:db8:2::1/64 to G0/1

Question 2

You are connected to R1. The network has three routers: R1, R2, and R3. R1's G0/0 is connected to R2's G0/0, and R1's G0/1 is connected to R3's G0/1. The goal is to configure R1 so that it can ping both R2 (192.0.2.2/30) and R3 (2001:db8:1::2/64). Currently, R1 cannot ping R2 due to a wrong subnet mask on R1's G0/0, and R3 is using an IPv6 EUI-64 address but R1 has been given a static IPv6 address that conflicts. Fix both issues and verify connectivity.

Accepted Answer

On G0/0, change the subnet mask to 255.255.255.252; on G0/1, remove the static IPv6 address and configure an EUI-64 address.. The problem has two issues. First, R1's G0/0 has IP 192.0.2.1 but its subnet mask is incorrectly set to 255.255.255.0 (/24) instead of the required 255.255.255.252 (/30) that matches R2's /30. This mask mismatch causes R1 to misclassify the subnet, preventing successful ping to R2. The fix is to change the mask to 255.255.255.252. Second, R1's G0/1 is configured with a static IPv6 address that duplicates R3's EUI-64 generated address (e.g., 2001:db8:1::2). This duplicate address breaks communication. The correct solution is to remove the static IPv6 address and enable EUI-64 on G0/1, allowing R1 to derive a unique interface ID from its own MAC address.

Answer

On G0/0, change the IP address to 192.0.2.2/30; on G0/1, change the IPv6 address to 2001:db8:1::2/64.

Answer

On G0/0, change the subnet mask to 255.255.255.0; on G0/1, change the IPv6 address to 2001:db8:1::1/64 with EUI-64.

Answer

On G0/0, change the IP address to 192.0.2.2/30; on G0/1, remove the static IPv6 address and configure an EUI-64 address.

Question 3

You are troubleshooting a wireless client association failure on a Cisco WLC. A client reports it can see the SSID 'GuestNet' but fails to connect, while another client using the same SSID connects fine. You must check the WLC configuration, identify the cause, and fix it so that both clients can associate successfully.

Accepted Answer

Enable WPA3 Transition Mode and set PMF to Optional.. Update the explanation to avoid implying PMF itself forces WPA3. Instead, note that WPA3 requires PMF, so the failing legacy client must support WPA3. In transition mode, WPA2 clients can connect with WPA2 and PMF optional.

Answer

Change the WLAN security to WPA2-PSK only and disable PMF.

Answer

Disable PMF on the WLAN and keep WPA3 enabled.

Answer

Change the WLAN to use WPA2-PSK with PMF Required.

Question 4

You are connected to the WLC via its management IP 192.168.10.10. A new corporate SSID 'SecureCorp' must be configured for WPA3-Personal with PSK 'Cisco123' on the 5 GHz radio only. The SSID should be broadcast. The WLAN must be mapped to interface 'corp_vlan' (VLAN 100). After configuration, a wireless client reports it cannot see or connect to the SSID. Troubleshoot and resolve the client's association failure.

Accepted Answer

Enable SSID broadcast for the SecureCorp WLAN.. The client cannot see the SSID because SSID broadcast is disabled. Although the administrator intended to broadcast the SSID, the actual WLAN configuration has the broadcast setting turned off. To resolve this, enable SSID broadcast on the WLAN. The security and VLAN settings are correct. Enabling broadcast allows the client to discover the network without manual entry.

Answer

Change the security mode to WPA2-Personal with the same PSK.

Answer

Reconfigure the WLAN to use interface 'management' instead of 'corp_vlan'.

Answer

Disable the 5 GHz radio and enable the 2.4 GHz radio for the SecureCorp WLAN.

Question 5

You are connected to the console of switch SW1. A user on VLAN 10 reports they cannot reach the internet (203.0.113.1). The switch is configured as a Layer 3 switch with SVIs. Identify and correct the misconfiguration that prevents the user's default gateway from functioning. The user's PC has IP address 192.168.10.50/24 and uses 192.168.10.1 as its default gateway.

Accepted Answer

The SVI for VLAN 10 has 'no ip proxy-arp' configured, and there is no default route on the switch.. The switch's SVI for VLAN 10 has 'no ip proxy-arp' configured, which prevents it from responding to ARP requests for the default gateway IP address. Additionally, the switch lacks a default route to forward traffic to the internet. Option A correctly identifies both issues.

Answer

The SVI for VLAN 10 has the wrong IP address configured; it should be 192.168.10.254 instead of 192.168.10.1.

Answer

The switch has a default route pointing to 203.0.113.1, but the SVI for VLAN 10 is missing the 'ip helper-address' command.

Answer

The VLAN 10 interface is administratively down, and the switch needs to be reloaded to apply the configuration.

Question 6

You are troubleshooting a connectivity issue for a remote worker who reports being unable to access the internet. The worker's PC is connected to switch S1, which is connected to router R1. You have console access to R1. The router's interface G0/0 is configured with IP 192.168.1.1/24, and the DHCP pool 'LAN' currently has network 192.168.1.0 255.255.255.0 and default-router 192.168.1.254. The PC has obtained an IP address of 192.168.1.100 from DHCP and a subnet mask of 255.255.255.0, but cannot ping 8.8.8.8. Identify the fault and configure R1 to restore internet access for the PC.

Accepted Answer

Change the default-router in the DHCP pool 'LAN' to 192.168.1.1. The PC received a valid IP address (192.168.1.100) from DHCP, proving the DHCP server is reachable and the network statement is correct. However, the pool’s default-router is set to 192.168.1.254, while the actual interface IP (the real gateway) is 192.168.1.1. The PC therefore uses an incorrect default gateway, blocking internet access. Changing the default-router to 192.168.1.1 fixes the gateway mismatch. Option B is wrong because the network statement already matches the subnet. Option C is unnecessary since no helper address is needed for a DHCP server on the same subnet. Option D would change the router’s IP to 192.168.1.254, creating further misalignment and breaking connectivity.

Answer

Change the network statement in the DHCP pool 'LAN' to 192.168.1.0 255.255.255.0

Answer

Add the command 'ip helper-address 192.168.1.254' on interface G0/0

Answer

Change the IP address of interface G0/0 to 192.168.1.254/24

Question 7

You are troubleshooting a client connectivity issue on VLAN 10. The client PC1 is connected to switch SW1, which is connected to router R1 acting as the default gateway. PC1 can ping its own IP and the default gateway (10.1.10.1) but cannot reach the internet. Identify the fault and apply the necessary fix on R1.

Accepted Answer

Configure a default route on R1: ip route 0.0.0.0 0.0.0.0 10.1.10.254. PC1 can ping its own IP and the gateway (10.1.10.1) but not the internet (8.8.8.8). The router R1 has no default route to forward traffic to the internet. The fix is to configure a default route on R1 pointing to the next-hop IP address of the upstream router (e.g., 10.1.10.254). On Ethernet, you must specify a next-hop IP; specifying only an exit interface (like GigabitEthernet0/0) would cause the router to ARP for every destination and fail, so option D is incorrect.

Answer

Configure a static route on R1: ip route 8.8.8.8 255.255.255.255 10.1.10.254

Answer

Configure a default route on R1: ip route 0.0.0.0 0.0.0.0 10.1.10.1

Answer

Configure a default route on R1: ip route 0.0.0.0 0.0.0.0 GigabitEthernet0/0

Question 8

You are troubleshooting a wired client connectivity issue on VLAN 10. PC1 (192.168.10.50/24) cannot reach the internet. The gateway is R1's subinterface G0/0.10 at 192.168.10.1. R1 has a default route to ISP router 203.0.113.1. From PC1, ping 192.168.10.1 fails, but ipconfig shows correct IP. R1's physical interface GigabitEthernet0/0 is administratively down. Fix the problem on R1 so that PC1 can ping its default gateway.

Accepted Answer

Enable the physical interface GigabitEthernet0/0 with 'no shutdown'.. PC1 has correct IP and cannot ping gateway 192.168.10.1. Because R1's physical interface GigabitEthernet0/0 is administratively down, subinterface G0/0.10 cannot process traffic. Enable the physical interface with 'no shutdown'. The default route is already present. The correct answer is A.

Answer

Configure 'no shutdown' on subinterface G0/0.10 and add a static route for 192.168.10.0/24 pointing to the ISP.

Answer

Change the IP address of subinterface G0/0.10 to 192.168.10.254 and add a default route via 203.0.113.1.

Answer

Enable VLAN 10 on the switch and configure trunking between the switch and R1.

Question 9

You are troubleshooting a wired client connectivity issue. A user on VLAN 10 (subnet 192.168.10.0/24) reports that they cannot reach the internet. The client PC is connected to switch SW1, which is connected to router R1. You have console access to the client PC and R1. Identify and fix the misconfiguration so that the client can ping the internet host 203.0.113.1.

Accepted Answer

Configure R1 as a DHCP server for VLAN 10, exclude the router's VLAN 10 IP (e.g., 192.168.10.1), provide the default gateway 192.168.10.1 to clients via DHCP, and add a default route on R1 via the ISP next-hop IP (e.g., 203.0.113.254).. The client PC likely has an APIPA address because no DHCP server is available for VLAN 10. R1 should be configured as a DHCP server for VLAN 10 and must provide the default gateway 192.168.10.1, which is on the same subnet as the client. R1 also needs a default route toward the ISP next-hop IP, not directly to the internet host 203.0.113.1. A default route must point to a next-hop router, not the final destination.

Answer

Change the client's IP address to a static IP in the 192.168.10.0/24 subnet and set the default gateway to 203.0.113.1.

Answer

Enable DHCP snooping on SW1 and configure the client port as trusted.

Answer

Configure a static route on the client PC to 203.0.113.1 via the router's IP.

Question 10

You are troubleshooting connectivity between R1 and R2. R1's GigabitEthernet0/0 interface is configured with a static IP of 10.0.0.1/30 but cannot ping its neighbor R2 at 10.0.0.2/30. R1 is using a 1000BASE-T SFP module to connect to a 1000BASE-LX/LH SFP on R2, but the link is down. Diagnose and resolve the issue by ensuring the correct SFP is used for the 2 km fiber run.

Accepted Answer

Replace the 1000BASE-T SFP with a 1000BASE-LX/LH SFP. No manual speed or duplex configuration is needed.. The link is down because 1000BASE-T (copper) and 1000BASE-LX/LH (fiber) are physically incompatible. Replace the SFP with a 1000BASE-LX/LH SFP. Gigabit fiber SFPs automatically operate at 1000 Mbps full duplex; no manual speed, duplex, or auto-negotiation commands are needed or applicable on the fiber port.

Answer

Keep the 1000BASE-T SFP and configure 'no negotiation auto', 'speed 1000', and 'duplex full' on R1.

Answer

Replace the 1000BASE-T SFP with a 1000BASE-LX/LH SFP, then configure 'speed 1000' and 'duplex full' on R1 without disabling auto-negotiation.

Answer

Replace the 1000BASE-T SFP with a 1000BASE-LX/LH SFP, then configure 'no negotiation auto' on R1 without setting speed and duplex.

Question 11

You are connected to R1 via the console. R1 and R2 are directly connected via their GigabitEthernet0/0 interfaces. Configure R1's G0/0 for 100 Mbps full-duplex operation. Then, diagnose and fix an auto-negotiation failure that prevents the link from coming up. Finally, replace the existing 1000BASE-T SFP with a 1000BASE-LX SFP to support a new 5 km fiber run. Ensure the link is up and working.

Accepted Answer

Configure speed 100 and duplex full on G0/0, then no shutdown. After the link is up, issue shutdown on the interface before physically swapping the SFP. Then remove the 1000BASE-T SFP and insert the 1000BASE-LX SFP, configure the interface with speed auto and duplex auto, issue no shutdown, and finally verify the link state.. After configuring speed 100 and duplex full on R1's G0/0 and issuing no shutdown, the initial link comes up. For the SFP replacement, issue shutdown on the interface before physically removing the 1000BASE-T SFP to prevent damage. After inserting the 1000BASE-LX SFP, configure speed auto and duplex auto so the interface renegotiates with the new optics, issue no shutdown, and verify the link is up.

Answer

Configure speed 100 and duplex full on G0/0, then no shutdown. After the link is up, remove the 1000BASE-T SFP and insert the 1000BASE-LX SFP; the interface will automatically detect the new SFP and adjust speed/duplex.

Answer

Configure speed 100 and duplex full on G0/0, then no shutdown. After the link is up, remove the 1000BASE-T SFP and insert the 1000BASE-LX SFP, then configure the interface with speed 1000 and duplex full to match the new SFP.

Answer

Configure speed 100 and duplex full on G0/0, then no shutdown. After the link is up, remove the 1000BASE-T SFP and insert the 1000BASE-LX SFP, then configure the interface with speed 100 and duplex full to maintain consistency.

Question 12

You are connected to R1. Configure the G0/0 interface to match the speed (100 Mbps) and duplex (full) of the connected switch port, then diagnose and fix an auto-negotiation failure that has caused excessive CRC errors. Finally, select and replace the SFP module on G0/0 with one that supports a 5 km fiber link, using the correct cable type.

Accepted Answer

Set speed 100, duplex full; replace SFP with 100BASE-LX; use single-mode fiber (SMF).. To match the connected switch port, hardcode speed 100 and duplex full on R1's G0/0. CRC errors indicate a speed/duplex mismatch; explicitly setting both ends to 100/full rather than auto-negotiation fixes the mismatch. For a 5 km single-mode fiber link at 100 Mbps, use a 100BASE-LX SFP (100BASE-LX10) with SMF. A 1000BASE-LX SFP is gigabit and cannot operate at speed 100; 1000BASE-SX uses multimode fiber; setting speed 1000 or leaving auto-negotiation does not match the given switch port.

Answer

Set speed 100, duplex half; replace SFP with 1000BASE-SX; use multimode fiber (MMF).

Answer

Set speed 1000, duplex full; replace SFP with 1000BASE-LX; use single-mode fiber (SMF).

Answer

Set no speed, no duplex (auto); replace SFP with 1000BASE-LX; use single-mode fiber (SMF).

Question 13

You are connected to R1 via the console. R1 is a new router that needs to be configured with a hostname, an encrypted privileged password 'cisco123', and a banner message 'Unauthorized access prohibited'. Additionally, SSH must be enabled for remote management using a domain name 'example.com' and a key size of 1024. The management interface is G0/0 with IP 192.168.1.1/24.

Accepted Answer

hostname R1
enable secret cisco123
banner motd #Unauthorized access prohibited#
ip domain-name example.com
crypto key generate rsa modulus 1024
line vty 0 4
transport input ssh
login local
username admin secret cisco123
interface g0/0
ip address 192.168.1.1 255.255.255.0
no shutdown. It includes all required commands: hostname, enable secret (encrypted), banner motd, ip domain-name, crypto key, line vty with transport input ssh and login local, and a local user 'admin' with secret. The stem requires an encrypted privileged password (enable secret) and SSH, but SSH login local needs a local user. Option A lacks the username command, so SSH login would fail. Option B uses unencrypted enable password and incorrect VTY authentication. Option C has both password and login local, which is contradictory. Option D is the only complete configuration.

Answer

hostname R1
enable secret cisco123
banner motd #Unauthorized access prohibited#
ip domain-name example.com
crypto key generate rsa modulus 1024
line vty 0 4
transport input ssh
login local
interface g0/0
ip address 192.168.1.1 255.255.255.0
no shutdown

Answer

hostname R1
enable password cisco123
banner motd #Unauthorized access prohibited#
ip domain-name example.com
crypto key generate rsa modulus 1024
line vty 0 4
transport input ssh
password cisco123
login
interface g0/0
ip address 192.168.1.1 255.255.255.0
no shutdown

Answer

hostname R1
enable secret cisco123
banner motd #Unauthorized access prohibited#
ip domain-name example.com
crypto key generate rsa modulus 1024
line vty 0 4
transport input ssh
password cisco123
login local
interface g0/0
ip address 192.168.1.1 255.255.255.0
no shutdown

Question 14

You are connected to the console of R1. The network uses IPv6 and you need to configure an IPv6 address on interface G0/0 using the EUI-64 format. The subnet is 2001:db8:acad:1::/64. The interface MAC address is 0011.2233.4455. After configuration, verify that the full IPv6 address is correct.

Accepted Answer

ipv6 address 2001:db8:acad:1:0211:22ff:fe33:4455/64. The EUI-64 method inserts FFFE in the middle of the MAC and flips the U/L bit. With the given MAC, the resulting interface ID is 0211:22FF:FE33:4455, forming the full IPv6 address.

Answer

ipv6 address 2001:db8:acad:1:0011:22ff:fe33:4455/64

Answer

ipv6 address 2001:db8:acad:1:0011:2233:4455/64

Answer

ipv6 address 2001:db8:acad:1:0211:2233:4455/64

Question 15

You are connected to the console of R1. The network uses IPv6 with EUI-64. R1's GigabitEthernet0/0 has MAC address 0011.2233.4455. You need to configure an IPv6 address on this interface using the prefix 2001:db8:1:1::/64 with EUI-64, and ensure the interface is operational.

Accepted Answer

ipv6 address 2001:db8:1:1::/64 eui-64. Uses the correct syntax 'ipv6 address 2001:db8:1:1::/64 eui-64', which configures the prefix and derives the interface ID automatically from the MAC address via EUI-64. Option A is invalid because specifying the full 128-bit address with the eui-64 keyword is not allowed; the eui-64 keyword requires only a prefix. Option C omits the eui-64 keyword, so it configures a static address without using EUI-64, which would not match the requirement to use EUI-64. Option D appends the MAC address after the eui-64 keyword, which is invalid syntax; the eui-64 keyword does not accept an explicit MAC address.

Answer

ipv6 address 2001:db8:1:1:0011:22ff:fe33:4455/64 eui-64

Answer

ipv6 address 2001:db8:1:1:0211:22ff:fe33:4455/64

Answer

ipv6 address 2001:db8:acad:1::/64 eui-64

CCNA Network Infrastructure and Connectivity Practice Test 6 — 15 Questions

Exhibit

CCNA Network Infrastructure and Connectivity Practice Test 6 — 15 Questions

Exhibit