CCNA Configuration Interview Questions

Prepare for your CCNA interview with our comprehensive guide on configuration questions and answers. This article covers essential topics including IP address configuration, VLAN setup, NAT, DHCP, and more. Ideal for CCNA candidates seeking to master network device configuration and excel in interviews.

CCNA Configuration Interview Questions

In the world of network engineering, configuring network devices correctly is a critical skill that CCNA candidates must master. As technology evolves and networks become more complex, the ability to configure routers, switches, and other network devices accurately is essential. This article will explore a series of common and advanced CCNA configuration interview questions that test candidates’ understanding and practical skills. Whether you're preparing for an upcoming interview or looking to brush up on your configuration knowledge, these questions will provide valuable insights into what to expect and how to excel.

1. What is the purpose of the interface command in Cisco IOS?

Answer: The interface command is used to enter the interface configuration mode in Cisco IOS. This allows the user to configure settings specific to a particular interface, such as IP address, subnet mask, and various interface-specific parameters.

2. How would you configure a static IP address on a Cisco router interface?

Answer: To configure a static IP address, enter the following commands in interface configuration mode:

Router(config)# interface GigabitEthernet0/1 Router(config-if)# ip address 192.168.1.1 255.255.255.0 Router(config-if)# no shutdown

3. Explain the purpose of the router ospf command.

Answer: The router ospf command is used to enter OSPF (Open Shortest Path First) routing process configuration mode. This command allows you to configure OSPF settings such as router ID, network advertisements, and other OSPF-specific parameters.

4. How can you enable SSH access on a Cisco device?

Answer: To enable SSH access, follow these steps:

Router(config)# hostname RouterName RouterName(config)# ip domain-name example.com RouterName(config)# crypto key generate rsa RouterName(config)# ip ssh version 2 RouterName(config)# username admin password AdminPass RouterName(config)# line vty 0 4 RouterName(config-line)# login local RouterName(config-line)# transport input ssh

5. What is the command to configure a VLAN on a Cisco switch?

Answer: To configure a VLAN, use the following commands:

Switch(config)# vlan 10 Switch(config-vlan)# name Sales Switch(config-vlan)# exit Switch(config)# interface GigabitEthernet0/1 Switch(config-if)# switchport mode access Switch(config-if)# switchport access vlan 10

6. How do you configure a default gateway on a Cisco router?

Answer: To configure a default gateway, use the following command:

Router(config)# ip route 0.0.0.0 0.0.0.0 192.168.1.254

7. Explain how to configure a DHCP server on a Cisco router.

Answer: To configure a DHCP server, use the following commands:

Router(config)# ip dhcp pool POOL1 Router(dhcp-config)# network 192.168.1.0 255.255.255.0 Router(dhcp-config)# default-router 192.168.1.1 Router(dhcp-config)# dns-server 8.8.8.8

8. What command is used to view the current VLAN configuration on a Cisco switch?

Answer: Use the following command to view VLAN configurations:

Switch# show vlan brief

9. How would you configure an ACL to deny all traffic from a specific IP address?

Answer: To configure an ACL (Access Control List) to deny traffic from a specific IP address, use these commands:

Router(config)# access-list 100 deny ip 192.168.1.100 0.0.0.0 any Router(config)# access-list 100 permit ip any any Router(config)# interface GigabitEthernet0/1 Router(config-if)# ip access-group 100 in

10. Describe the process to configure port security on a Cisco switch.

Answer: To configure port security, follow these steps:

Switch(config)# interface GigabitEthernet0/1 Switch(config-if)# switchport mode access Switch(config-if)# switchport port-security Switch(config-if)# switchport port-security maximum 2 Switch(config-if)# switchport port-security violation restrict Switch(config-if)# switchport port-security mac-address sticky

11. How do you configure a router to use NAT (Network Address Translation)?

Answer: To configure NAT, use the following commands:

Router(config)# access-list 1 permit 192.168.1.0 0.0.0.255 Router(config)# ip nat inside source list 1 interface GigabitEthernet0/1 overload Router(config)# interface GigabitEthernet0/1 Router(config-if)# ip nat outside Router(config)# interface GigabitEthernet0/2 Router(config-if)# ip nat inside

12. What is the command to configure a static route on a Cisco device?

Answer: To configure a static route, use the command:

Router(config)# ip route 10.1.1.0 255.255.255.0 192.168.1.1

13. How would you configure an interface to use an IP address dynamically assigned by DHCP?

Answer: Use the following commands to configure an interface to obtain an IP address via DHCP:

Router(config)# interface GigabitEthernet0/1 Router(config-if)# ip address dhcp Router(config-if)# no shutdown

14. Explain how to configure HSRP (Hot Standby Router Protocol) on a Cisco router.

Answer: To configure HSRP, follow these commands:

Router(config)# interface GigabitEthernet0/1 Router(config-if)# standby 1 ip 192.168.1.254 Router(config-if)# standby 1 priority 110 Router(config-if)# standby 1 preempt

15. What command would you use to save the current configuration on a Cisco device?

Answer: To save the current configuration, use the command:

Router# write memory

Alternatively, you can use:

Router# copy running-config startup-config

16. How do you configure a Cisco switch to use a specific NTP server?

Answer: To configure an NTP server, use the following command:

Switch(config)# ntp server 192.168.1.100

17. Explain how to configure a GRE (Generic Routing Encapsulation) tunnel on a Cisco router.

Answer: To configure a GRE tunnel, use these commands:

Router(config)# interface Tunnel0 Router(config-if)# ip address 10.1.1.1 255.255.255.0 Router(config-if)# tunnel source 192.168.1.1 Router(config-if)# tunnel destination 192.168.2.1

18. What is the command to configure a DHCP relay agent on a Cisco router?

Answer: To configure a DHCP relay agent, use:

Router(config)# interface GigabitEthernet0/1 Router(config-if)# ip helper-address 192.168.1.100

19. How do you configure a Cisco device to use AAA (Authentication, Authorization, and Accounting)?

Answer: To configure AAA, use these commands:

Router(config)# aaa new-model Router(config)# aaa authentication login default local Router(config)# aaa authorization exec default local Router(config)# aaa accounting exec default start-stop group local Router(config)# username admin password AdminPass

20. Explain the process to configure a loopback interface on a Cisco device.

Answer: To configure a loopback interface, use the following commands:

Router(config)# interface Loopback0 Router(config-if)# ip address 10.10.10.1 255.255.255.0

21. How would you configure IP addressing for a Cisco router’s interface?

Answer: To configure IP addressing, enter interface configuration mode and use:

Router(config)# interface GigabitEthernet0/1 Router(config-if)# ip address 192.168.1.1 255.255.255.0 Router(config-if)# no shutdown

22. Describe the steps to configure a static NAT entry on a Cisco router.

Answer: To configure static NAT, use the following commands:

Router(config)# ip nat inside source static 192.168.1.10 203.0.113.10

23. How do you configure a Cisco switch port as an access port?

Answer: To configure a switch port as an access port, use these commands:

Switch(config)# interface GigabitEthernet0/1 Switch(config-if)# switchport mode access Switch(config-if)# switchport access vlan 10

24. What command is used to view the current interface configuration on a Cisco device?

Answer: To view the current interface configuration, use:

Router# show running-config interface GigabitEthernet0/1

25. How would you configure a VLAN trunk between two Cisco switches?

Answer: To configure a VLAN trunk, use the following commands on both switches:

Switch(config)# interface GigabitEthernet0/1 Switch(config-if)# switchport mode trunk Switch(config-if)# switchport trunk allowed vlan 10,20,30

26. Explain the process to configure a Port-Channel (EtherChannel) on Cisco switches.

Answer: To configure EtherChannel, use these commands:

Switch(config)# interface range GigabitEthernet0/1 - 2 Switch(config-if-range)# channel-group 1 mode active Switch(config)# interface Port-channel1 Switch(config-if)# switchport mode trunk

27. What is the command to configure an IP address on a Cisco switch VLAN interface?

Answer: To configure an IP address on a VLAN interface, use:

Switch(config)# interface VLAN 10 Switch(config-if)# ip address 192.168.1.1 255.255.255.0 Switch(config-if)# no shutdown

28. How do you configure a Cisco router to use a specific DNS server?

Answer: To configure a DNS server, use:

Router(config)# ip name-server 8.8.8.8

29. Describe the process to configure PPP (Point-to-Point Protocol) on a Cisco router.

Answer: To configure PPP, use these commands:

Router(config)# interface Serial0/0 Router(config-if)# encapsulation ppp Router(config-if)# ppp chap chap-password

30. How would you configure a Cisco router to use RIP (Routing Information Protocol)?

Answer: To configure RIP, use the following commands:

Router(config)# router rip Router(config-router)# version 2 Router(config-router)# network 192.168.1.0 Router(config-router)# no auto-summary

31. Explain the command to configure an IP address for a loopback interface on a Cisco router.

Answer: To configure a loopback interface, use:

Router(config)# interface Loopback1 Router(config-if)# ip address 10.10.10.1 255.255.255.255

32. How do you configure SNMP (Simple Network Management Protocol) on a Cisco device?

Answer: To configure SNMP, use:

Router(config)# snmp-server community public RO Router(config)# snmp-server location Office Router(config)# snmp-server contact Admin

33. What is the command to configure a Cisco switch for RSTP (Rapid Spanning Tree Protocol)?

Answer: To configure RSTP, use:

Switch(config)# spanning-tree mode rapid-pvst

34. How would you configure a Cisco router to use EIGRP (Enhanced Interior Gateway Routing Protocol)?

Answer: To configure EIGRP, use the following commands:

Router(config)# router eigrp 100 Router(config-router)# network 192.168.1.0 0.0.0.255

35. Describe how to configure a Cisco switch port for voice VLAN.

  • Answer: To configure a voice VLAN, use:
    Switch(config)# interface GigabitEthernet0/1 Switch(config-if)# switchport voice vlan 20

36. What command is used to configure a VPN (Virtual Private Network) on a Cisco device?

Answer: To configure a VPN, use the following commands:

Router(config)# crypto isakmp policy 10 Router(config-isakmp)# encryption aes Router(config-isakmp)# authentication pre-share Router(config-isakmp)# key cisco123 Router(config)# crypto ipsec transform-set TRANSFORM1 esp-aes esp-sha-hmac Router(config)# crypto map VPN 10 ipsec-isakmp Router(config-crypto-map)# set peer 203.0.113.1 Router(config-crypto-map)# set transform-set TRANSFORM1 Router(config-crypto-map)# match address 100

37. How do you configure a Cisco router for NAT overload?

Answer: To configure NAT overload (PAT), use:

Router(config)# access-list 1 permit 192.168.1.0 0.0.0.255 Router(config)# ip nat inside source list 1 interface GigabitEthernet0/1 overload Router(config)# interface GigabitEthernet0/1 Router(config-if)# ip nat outside Router(config)# interface GigabitEthernet0/0 Router(config-if)# ip nat inside

38. Describe the process to configure DHCP reservation on a Cisco router.

Answer: To configure DHCP reservation, use:

Router(config)# ip dhcp pool POOL1 Router(dhcp-config)# host 192.168.1.10 255.255.255.0 Router(dhcp-config)# client-identifier 0100.5e00.4c00.0001 Router(dhcp-config)# hardware-address 00:0c:29:4f:2d:51

39. How would you configure a Cisco device to use a static IP address for DNS resolution?

Answer: To configure a static DNS server, use:

Router(config)# ip name-server 8.8.8.8 Router(config)# ip name-server 8.8.4.4

40. Explain how to configure a Cisco router to use IPv6 addressing.

Answer: To configure IPv6 addressing, use:

Router(config)# interface GigabitEthernet0/1 Router(config-if)# ipv6 address 2001:db8::1/64 Router(config-if)# ipv6 enable

41. What command is used to configure the OSPF router ID on a Cisco device

Answer: To configure the OSPF router ID, use:

Router(config)# router ospf 1 Router(config-router)# router-id 1.1.1.1

42. How do you configure a Cisco router to enable IP routing?

Answer: To enable IP routing, use:

Router(config)# ip routing

43. Describe the process to configure a router to use EIGRP with multiple autonomous systems.

Answer: To configure EIGRP with multiple autonomous systems, use:

Router(config)# router eigrp 10 Router(config-router)# network 192.168.1.0 Router(config-router)# autonomous-system 20 Router(config-router)# network 10.0.0.0 Router(config-router)# autonomous-system 30

44. What is the command to configure a Cisco router to use a routing protocol?

Answer: The command to configure a routing protocol, such as RIP, is:

Router(config)# router rip Router(config-router)# network 192.168.1.0

45. How do you configure a Cisco device to support IPv6 routing?

Answer: To support IPv6 routing, use:

Router(config)# ipv6 unicast-routing Router(config)# interface GigabitEthernet0/1 Router(config-if)# ipv6 address 2001:db8::1/64 Router(config-if)# ipv6 enable

46. Explain the process to configure IP SLA on a Cisco router.

Answer: To configure IP SLA, use:

Router(config)# ip sla 1 Router(config-ip-sla)# icmp-echo 192.168.1.1 Router(config-ip-sla)# frequency 60 Router(config)# ip sla schedule 1 life forever start-time now

47. How would you configure a Cisco device for VLAN routing?

Answer: To configure VLAN routing, use:

Router(config)# interface GigabitEthernet0/1.10 Router(config-if)# encapsulation dot1Q 10 Router(config-if)# ip address 192.168.1.1 255.255.255.0 Router(config-if)# no shutdown

48. What command is used to configure a Cisco device with IPv6 static routes?

Answer: To configure IPv6 static routes, use:

Router(config)# ipv6 route 2001:db8::/32 2001:db8:1::1

49. How do you configure a Cisco router to use NAT for a specific subnet?

Answer: To configure NAT for a subnet, use:

Router(config)# access-list 1 permit 192.168.1.0 0.0.0.255 Router(config)# ip nat inside source list 1 interface GigabitEthernet0/1 overload

50. Describe the process to configure a Cisco device to use VTP (VLAN Trunking Protocol).

Answer: To configure VTP, use these commands:

Switch(config)# vtp mode server Switch(config)# vtp domain example.com Switch(config)# vtp password mypassword.

Conclusion

Mastering configuration tasks is fundamental for any network professional, and being well-prepared for configuration-related questions in a CCNA interview can set you apart from other candidates. By understanding these configuration scenarios and commands, you'll be better equipped to handle real-world networking challenges and demonstrate your technical expertise during your interview. As networks continue to grow in complexity, maintaining a strong grasp of configuration principles is essential for achieving success in your CCNA journey.