The following statement about the upgrading of H3C network equipment is correct ______ . (Multiple choices)

The following statement about the upgrading of H3C network equipment is correct ______ . (Multiple choices)
A . Using Xmodem to upgrade can achieve the same speed as FTP
B . When using FTP to upgrade, the device can only be an FTP client
C . When the device cannot boot to the command line mode and the operating system software needs to be upgraded, only the Xmodem mode can be used
D . In an environment where the client and server are not easy to interact with, you can use TFTP to upgrade

Answer: D

Explanation:

The device can be used as a client or server

TFTP 69 Simple File Transfer Protocol

If you cannot enter the device, you can upgrade through ftp / tftp / Xmodem through the bootrom menu : when the device cannot boot to the command line mode and you need to upgrade the operating system software , use the operation function provided by the BOOTROM menu in the BOOTROM mode , using ftp / tftp enables the device to boot normally and boot into command line mode.

If the network connection between FTP and TFTP server and the device cannot be achieved , it is only adopted in the BOOTROM mode through the console port

Xmodem completes the upgrade and enables the device to boot normally to the command line mode