100-150 Question 245
Select 3A network technician is troubleshooting a connectivity issue on a Layer 2 switch. They suspect the issue is related to incorrect VLAN assignments. Which combination of commands should they use to verify the VLAN configuration and identify the connected devices' MAC addresses on the switch?
- A
show vlan brief
- B
show mac address-table
- C
show cdp neighbors
- D
show ip route
- E
show run
Show answer and explanation
Correct answers: A, B, E
Explanation
To troubleshoot VLAN-related issues, the technician needs to verify VLAN configurations, identify which devices are connected to the switch, and check the current running configuration. The 'show vlan brief' command provides details about VLAN assignments, the 'show mac address-table' command maps MAC addresses to switch ports and VLANs, and the 'show run' command shows the current port and VLAN configurations. These commands collectively help identify and resolve VLAN misconfiguration issues.
- A. Correct.
The 'show vlan brief' command displays the VLANs configured on the switch and their associated ports, which is critical for verifying VLAN assignments.
- B. Correct.
The 'show mac address-table' command shows the MAC addresses of devices connected to the switch and their associated interfaces, helping to identify the connected devices and their VLANs.
- C. Incorrect.
The 'show cdp neighbors' command is used to view directly connected Cisco devices but does not provide information about VLANs or MAC addresses.
- D. Incorrect.
The 'show ip route' command is used for Layer 3 routing information and is not relevant for VLAN troubleshooting on a Layer 2 switch.
- E. Correct.
The 'show run' command displays the running configuration, which includes VLAN and interface configurations. This is useful for verifying VLAN assignments and port settings.