ICND1 Troubleshooting 3

Question 1

A switch port is in 'err-disabled' state. What is the most common cause of this condition?

Accepted Answer

Port security violation

Answer

Port security violations are the most common cause of a port entering the err-disabled state when the maximum MAC address count is exceeded.

Question 2

When troubleshooting a VLAN connectivity issue, a host in VLAN 10 cannot communicate with a host in VLAN 20. What is required for inter-VLAN communication?

Accepted Answer

A Layer 3 device or router-on-a-stick configuration

Answer

Inter-VLAN routing requires a Layer 3 device such as a router or multilayer switch to route traffic between VLANs.

Question 3

You cannot Telnet to a remote router. The 'show line vty 0 4' output shows no password set. What must you configure?

Accepted Answer

VTY line password

Answer

A VTY line password must be configured with the 'password' command and 'login' enabled for Telnet access to succeed.

Question 4

A router interface shows 'FastEthernet0/0 is up, line protocol is down.' What is the most likely cause?

Accepted Answer

Keepalive mismatch or encapsulation issue

Answer

Up/down status means the physical layer is functional but Layer 2 is failing, typically due to a keepalive or encapsulation mismatch.

Question 5

Which command should you use to verify that NAT translations are occurring correctly on a Cisco router?

Accepted Answer

show ip nat translations

Answer

'show ip nat translations' displays active NAT translation entries showing inside local and global address mappings.

(ICND1) Interconnecting Cisco Networking Devices Part 1 Practice Test

(ICND1) Interconnecting Cisco Networking Devices Part 1 Practice Test

ICND1 Troubleshooting 3