Final answer:
Using the command erase startup-config and reload does not automatically remove existing VLANs from a switch. The administrator should use the no vlan command followed by the VLAN number to remove VLANs.
Step-by-step explanation:
When an administrator uses the erase startup-config command on a switch, it clears the configuration stored in the switch's non-volatile memory. However, this command does not automatically remove existing VLANs.
To remove VLANs from a switch, the administrator needs to use the no vlan command followed by the VLAN number. For example, to remove VLAN 10, the command would be no vlan 10.
After removing the VLANs, it's important to save the configuration using the write memory command to ensure that the changes persist after a reload.
Saving the configuration using the write memory command is essential to ensure the changes persist after a reload.