我们一般在工作中,经常会遇到IOS莫名其妙的丢失,有时候很突然,有时候很棘手,如果网络因为你的失误而中断,你的责任会很重要,所以大家一定要掌握恢复IOS的方法。
实验拓扑:
![网络工程师交换试验手册之二十五:详细讲授利用xmodem来恢复IOS_试验手册](http://bbs.51cto.com/p_w_uploads/month_0706/1_X1Eu2NfcT4Wx.bmp?x-oss-process=image/resize,m_fixed,w_1184)
pc
实验步骤:
IOS丢失以后,所有的设备都会启动最小启动模式。
rommon 1 > confreg 回车
Configuration Summary
enabled are:
load rom after netboot fails
console baud: 9600
boot: p_w_picpath 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: p_w_picpath 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! 需要主意的是,这是科学估算时间和实际的时间相差很远,实际如果10几M的话要3个多小时。希望大家预备好咖啡和甜品准备漫长的等待,本人深有体会,呵呵!
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
(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)
(videre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, Vector = 0x500, 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: p_w_picpath 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 [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: p_w_picpath 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)
然后关闭这个超级终端,重新建立一个超级终端连接,一切就OK了
通过Xmodem升级2610的IOS实例
如果你不小心使用了命令erase flash 那么发生什么就可想而知了。因此,建议在你拿到路由器等网络设备时 最好先将它的IOS等操作系统备份出来,以备万一!
本篇主要介绍通过Xmodem上传IOS的过程(以2610为例,不过这个方法用在其他设备上没什么太大区别)
准备工作,只要有Cisco原配的线缆就可以(注:Xmodem与实际的modem没有任何联系 只是一个传输协议 数据是通过终端的串口和路由器的Console口灌进去的)
在没有IOS的情况下 系统只能进入Rommon状态,在这个状态下只能见到如下命令:
rommon 8 > ?
alias set and display aliases command
boot boot up an external process
break set/show/clear the breakpoint
confreg configuration register utility
cont continue executing a downloaded p_w_picpath
context display the context of a loaded p_w_picpath
cookie display contents of cookie PROM in hex
dev list the device table
dir list files in file system
dis display instruction stream
dnld serial download a program module
frame print out a selected stack frame
help monitor builtin command help
history monitor command history
meminfo main memory information
repeat repeat a monitor command
reset system reset
set display the monitor variables
stack produce a stack trace
sync write monitor environment to NVRAM
sysret print out info from last system return
tftpdnld tftp p_w_picpath download
unalias unset an alias
unset unset a monitor variable
xmodem x/ymodem p_w_picpath download
在这个模式下,输入Xmodem
rommon 9 > xmodem
会提示如下警告:
WARNING: All existing data in bootflash will be lost!
Invoke this application only for disaster recovery.
Do you wish to continue? y/n [n]: y
Ready to receive file ? ...
然后在超级终端的传送栏目=> 选择发送选项 => 再选择Xmodem 并指明IOS所在的路径即开始上传IOS,等待时间很长,视IOS的大小和传输速度。对于初次做IOS上传,建议不要去修改什么传输速率。传完以后 对整个系统初始化 界面如下:
Erasing flash at 0x603c0000
program flash location 0x602f0000
Download Complete!
program load complete, entry point: 0x80008000, size: 0x2f0074
Self decompressing the p_w_picpath : #################################################
################################################################################
################################################################################
################################################################# [OK]
Restricted Rights Legend
Use, duplication, or disclosure by the Government is
subject to restrictions as set forth in subparagraph
(c) of the Commercial Computer Software - Restricted
Rights clause at FAR sec. 52.227-19 and subparagraph
(c) (1) (ii) of the Rights in Technical Data and Computer
Software clause at DFARS sec. 252.227-7013.
Cisco Systems, Inc.
170 West Tasman Drive
San Jose, California 95134-1706
Cisco Internetwork Operating System Software
IOS (tm) C2600 Software (C2600-I-M), Version 11.3(6)T, RELEASE SOFTWARE (fc1)
Copyright (c) 1986-1998 by Cisco Systems, Inc.
Compiled Tue 06-Oct-98 18:42 by ccai
Image text-base: 0x80008084, data-base: 0x80554578
Cisco 2610 (MPC860) processor (revision 0x202) with 12288K/4096K bytes of memory
.
Processor board ID JAB0233005Z (3677578902)
M860 processor: part number 0, mask 32
Bridging software.
X.25 software, Version 3.0.0.
1 Ethernet/IEEE 802.3 interface(s)
1 Serial network interface(s)
32K bytes of non-volatile configuration memory.
4096K bytes of processor board System flash (Read/Write)
Press RETURN to get started!
00:00:06: %LINK-3-UPDOWN: Interface Ethernet0/0, changed state to up
00:00:06: %LINK-3-UPDOWN: Interface Serial0/0, changed state to up
00:00:06: %SYS-5-CONFIG_I: Configured from memory by console
00:00:06: %SYS-5-RESTART: System restarted --
Cisco Internetwork Operating System Software
IOS (tm) C2600 Software (C2600-I-M), Version 11.3(6)T, RELEASE SOFTWARE (fc1)
Copyright (c) 1986-1998 by Cisco Systems, Inc.
Compiled Tue 06-Oct-98 18:42 by ccai
00:00:07: %LINEPROTO-5-UPDOWN: Line protocol on
WL_bank_2610_2>Interface Ethernet0/0, changed state to up
00:00:07: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0/0, changed sta
te to up
00:00:07: %LINEPROTO-5-UPDOWN: Line protocol on Interface Loopback0, changed sta
te to up
实验总结:
我有过这样的经历,因为没有及时修复IOS而得到上级的责备,有些时候这些技能都是我们必须掌握的。