先打开超级终端，进入rommon 模式（Ctrl+Break组合键），键入confreg,如下：
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rommon 1 > confreg 回车
Configuration Summary
enabled are:
load rom after netboot fails
console baud: 9600
boot: image specified by the boot system commands
or default to: cisco2-C2600
do you wish to change the configuration? y/n [n]: y (选择 yes)
enable "diagnostic mode"? y/n [n]: n (选择 no) enable "use net in IP bcast address"? y/n [n]: n (选择 no) disable "load rom after netboot fails"? y/n [n]: n (选择 no) enable "use all zero broadcast"? y/n [n]: n (选择 no) enable "break/abort has effect"? y/n [n]: n (选择 no) enable "ignore system config info"? y/n [n]: n (选择 no) change console baud rate? y/n [n]: y (选择 yes) enter rate: 0 = 9600,1 = 4800,2 = 1200,3 = 2400 4 = 19200,5 = 38400,6 = 57600,7 = 115200 [0]: 7 (选择 7,用最大的115200速率的xmodem传输) change the boot characteristics? y/n [n]: n (选择 no) Configuration Summary enabled are: load rom after netboot fails console baud: 115200 boot: image specified by the boot system commands or default to: cisco2-C2600 do you wish to change the configuration? y/n [n]: n (选择 no) You must reset or power cycle for new config to take effect rommon 2 > reset 回车 注意：在此时键入 reset键之前，开始定义串口速度（我的电脑---端口属性----串口速度调为115200），然后再修改超级终端里设置速率为115200，记住， 一定这么做！否则出现乱码！ 然后关闭这个超级终端，重新建立一个超级终端连接，（期间系统重新启动）启动后，出现 rommon 1> 提示符 然后,输入 rommon 1> xmodem -r Do not start the sending program yet... Invoke this application only for disaster recovery. Do you wish to continue? y/n [n]: y (选择 yes) Ready to receive file ... 此时，在超级终端的菜单上的“传送”---“发送文件”----选择IOS镜像文件所在地以及选择使用“xmodem”协议，点击“发送”即可 然后等待10-20分钟左右就把3-6M的IOS灌进去了！ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ （修改回计算机串口与超级终端、路由器confreg下的xmodem等9600的传输速率） （注：实际用的时候，我发现这个命令总是改不成功，后来发现在line con 0下面有了一个speed 115200，所以即使改register成功，启动以后router又执行speed 115200,还是不行，所以如果有这个问题，记得把这个语句no掉） Router>en 进入新IOS的特权模式 Router#reload 重启系统 Proceed with reload? [confirm] 回车 00:01:04: %sYS-5-RELOAD: Reload requested System Bootstrap,Version 11.3(2)XA4,RELEASE SOFTWARE (fc1) copyright (c) 1999 by cisco Systems,Inc. TAC:Home:SW:IOS:Specials for info PC = 0xfff0a530,Vector = 0x500,SP = 0x680127b0 C2600 platform with 24576 Kbytes of main memory PC = 0xfff0a530,SP = 0x80004684 monitor: command "boot" aborted due to user interrupt rommon 1 > confreg （ 输入“confreg”命令） Configuration Summary enabled are: load rom after netboot fails console baud: 115200 boot: image specified by the boot system commands or default to: cisco2-C2600 do you wish to change the configuration? y/n [n]: y (选择 yes) enable "diagnostic mode"? y/n [n]: n (选择 no) enable "use net in IP bcast address"? y/n [n]: n (选择 no) disable "load rom after netboot fails"? y/n [n]: n (选择 no) enable "use all zero broadcast"? y/n [n]: n (选择 no) enable "break/abort has effect"? y/n [n]: n (选择 no) enable "ignore system config info"? y/n [n]: n (选择 no) change console baud rate? y/n [n]: y (选择 yes) enter rate: 0 = 9600,7 = 115200 [7]: 0 (选择 0,改回用标准速率速率9600的xmodem传输) change the boot characteristics? y/n [n]: n (选择 no) Configuration Summary enabled are: load rom after netboot fails console baud: 9600 boot: image specified by the boot system commands or default to: cisco2-C2600 do you wish to change the configuration? y/n [n]: n You must reset or power cycle for new config to take effect rommon 2 > 此时手工改回计算机串口与超级终端2者传输速率为9600 然后敲入 rommon 2 >reset ( 最好关电源)
