任务 2：恢复交换机到初始化设置
步骤 1：进入交换机 SW1 的命令行界面，进入特权模式
Switch>enable Switch#
步骤 2：使用 erase startup-config 命令清除启动配置文件
Switch#erase startup-config Erasing the nvram filesystem will remove all configuration files! Continue? [confirm] [OK] Erase of nvram: complete Switch#
步骤 3：使用 delete vlan.dat 命令清除 vlan 数据库文件
Switch#delete vlan.dat Delete filename [vlan.dat]? Delete flash:vlan.dat? [confirm] %Error deleting flash:vlan.dat (No such file or directory) //如果 vlan.dat 已被删除过，则会出现这个提示，没关系继续往下做 Switch#
步骤 4：使用 reload 命令重启交换机
Switch#reload System configuration has been modified. Save? [yes/no]: no Proceed with reload? [confirm]
按下回车 步骤 5：待交换机重启后，看到一下提示，说明交换机回到了出厂设置
--- System Configuration Dialog --- Would you like to enter the initial configuration dialog? [yes/no]: