如果用户口令丢失，可以进入boot 菜单：

    boot menu

    1. download application file to flash

    2. select application file to boot

    3. display all files in flash

    4. delete file from flash

    5. modify bootrom password

    6. enter bootrom upgrade menu

    7. skip current configuration file

    8. set bootrom password recovery

    9. set switch startup mode

    0. reboot

    enter your choice(0-9):

    选择7，然后重新启动交换机，那么系统在启动后用户密码会被删除。