通过 console 口升级，使用Console 线和网线将与PC 机连接起来。使用超级
终端（默认波特率9600bps，数据位8bit，无校验位，1bit 停止位，无流控制）登陆防火
墙的命令行界面。
打开 TFTP 软件，设置好软件的upload and download directory。将防火墙的一个接口
地址设为与PC 机地址同一网段。例如，将ethernet 1 接口设为192.168.3.1/24，自己
的PC 机设为192.168.3.180/24。
在命令行界面中输入save software from tftp 192.168.3.180 ns5gt.5.0.0r8.1 to
flash，回车。
如果成功，命令行界面会显示如下
5gt_3-> save software from tftp 192.168.3.180 ns5gt.5.0.0r8.1 to flash
Load software from TFTP 192.168.3.180 (file: ns5gt.5.0.0r8.1).
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
tftp received octets = 5390336
tftp success!
TFTP Succeeded
Save to flash. It may take a few minutes ...platform = 18, cpu = 12, version =
16
update new flash image (01bb3870,5390336)
platform = 18, cpu = 12, version = 16
offset = 20, address = 1900000, size = 5385716
date = 3136, sw_version = 28008000, cksum = 76e973e8
Program flash (5390336 bytes) ...
sec_size :16384 align_support 1 , mode 0
++++++++++++++++++++++++++++++++++++++++++++++++
++++++++++++++++++++++++++++++++++++++++++++++++
++++++++++++++++++++++++++++++++++++++++++++++++
+++++++++++++++++++++++++++++++++++++++++done
Done
然后重启防火墙。
通过命令行升级 OS，无须考虑版本问题。
如有必要通过 Telnet 进行远程的升级，那就需要PC 机和防火墙都有一个公网地址，且链
路速度不是很慢。