思科IOS误删除如何恢复
思科拥有丰富的行业经验、先进的技术，路由器功能也在世界遥遥领先，那么你知道思科IOS误删除如何恢复吗?下面是学习啦小编整理的一些关于思科IOS误删除如何恢复的相关资料，供你参考。
思科IOS误删除恢复的方法1:TFTP
近来发现许多网友因升级错误的IOS而丢失端口，现转贴以下文章，帮助大家在ROMMON下恢复IOS:
在ROMMON状态下，恢复2600和3600系列路由器的IOS
不小心把IOS删掉或者升级IOS失败，重起后进入ROMMON(ROMMON状态是ROM MONITOR的缩写)状态，是比较常见的事，对一个新手而言，前者的可能要大些。两者都可能使路由器进入ROMMON状态，不能进行正常的路由转发功能和软件配置，在这种模式下，原IOS中的大部分命令都无法使用。那怎么办呢?根据Cisco网站的资料，我翻译整理了两种常用的方法：1.使用TFTP恢复IOS;2.使用Xmodem恢复IOS.不同的路由器的命令有些不一样，这里以2600和3600系列路由为例，但是思路应该是差不多的，下面分开讲一下这两种方法：
在进行恢复之前，可以先看一下路由器的Flash里文件，用命令：dir flash:;注意命令中flash后面跟冒号(：)，执行命令后会显示flash现存的IOS大小和文件名，如下面：
1. rommon 1 》 dir flash:
File size Checksum File name
2179331 bytes (0x214103)
0x7b95 c1600-nsy-mz_112-15a_p
如果File name和Filesize的两项都是符合你的要求的，正确无误，那么你就不必要进行升级。这样也许是你的config-register的设置有问题，正常的一般config-register应该是0x2102的。注意0x2102中的最后一位值2, 最后一位值在2到F都是正常的。注意config-register的值控制着路由器的启动!如果最后一位数值不是在这个范围内，可以使用confreg 命令来改变它的值。关于config-register的16bit的每bit的含意，可以看一下cisco的技术资料，这里就不多说了。如果File name和File size的两项有一项是错的，那就进行下面的升级步骤：
一、 使用TFTP恢复IOS
使用交叉的网线连接你的路由器以太口和装有TFTP Server软件的PC机，在PC机上启动TFTPServer软件，并把新的IOS文件放在TFTP server所在目录的根目录下，如：你的TFTP Server软件在机器装的是Cisco TFTP Server目录，那么就把新的IOS文件放在Cisco TFTP Server目录下就可以了。用控制线将调试机器与路由器连接起来。
接下来的事就是在路由器进行操作了，在路由器上首先要设置一下ROMMON状态的环境变量，注意所有的环境变量都是大小写敏感的，一定要注意了!往往出错就是因为这个原因。具体下面设置如下：
打开机器的超级终端工具，连接上ROUTER,此时窗口中出现
的命令行提示符为： ROMMON 1 》 (其中"1"代表命令行的行数)。在提示符后输入命令：
ROMMON 1 》IP_ADDRESS= ROUTER的IP地址(要和TFTP软件所在的机器在同一网段内)
ROMMON 2 》IP_SUBNET_MASK= ROUTER的子网掩码
ROMMON 3 》DEFAUT_GATEWAY= 默认网关地址 (可以没有，也可以是TFTP服务器)
ROMMON 4 》TFTP_SERVER= TFTP 服务器IP地址
ROMMON 5 》TFTP_FILE= IOS文件名(只给出文件名，不需要路径)
ROMMON 6 》tftpdnld 回车
注意：前面的几条命令必须使用大写，而最后的tftpdnld则要用小写。设置完后要用sync命令保存环境变量到NVRAM,用set命令进行察看设置。
在tftpdnld命令执行后，只要根据提示选择，就可完成文件的传输。当文件传输完后，将自动回到命令行下，输入reset重启ROUTER,重启后就又回到了熟悉的IOS模式下 甚至连以前配置的信息都不会丢失。
下面是具体的例子：
Example
rommon 16 》 IP_ADDRESS=172.16.0.1
rommon 17 》 IP_SUBNET_MASK=255.255.255.0
rommon 18 》 DEFAULT_GATEWAY=172.16.0.2
rommon 19 》 TFTP_SERVER=172.16.0.2
rommon 20 》 TFTP_FILE=c2600-is-mz.113-2.0.3.Q
rommon 21 》 tftpdnld
IP_ADDRESS: 172.16.0.1
IP_SUBNET_MASK: 255.255.255.0
DEFAULT_GATEWAY: 172.16.0.2
TFTP_SERVER: 172.16.0.2
TFTP_FILE: c2600-is-mz.113-2.0.3.Q
Invoke this command for disaster recoveryonly.
WARNING: all existing data in all partitions on flash will be lost!
Do you wish to continue? y/n: [n]: y
Receiving c2600-is-mz.113-2.0.3.Q from172.16.0.2 !!!!!.!!!!!!!!!!!!!!!!!!!.!!
File reception completed.
Copying file c2600-is-mz.113-2.0.3.Q toflash.
Erasing flash at 0x607c0000
program flash location 0x60440000
rommon 22 》
注意的几个问题
①在连接运行tftp server的PC 机至路由器时，必需使用路由器的第一个以太口，即Ethernt0(对2500系列等)，Ethernet0/0(对2600系列等)，其它系列略有差别，可根据使用手册进行确定。
②在使用连接电缆时，一定要用交叉线，因这种情况属DTE与DCE之间的连接。
③在运行tftp server的PC 机上，一定要有相应的路由器的IOS印象文件，可以通过多种渠道和多种方式获得该文件。
④tftp server的地址可以随意定义，但必须与路由器定义的地址在同一网段上。
思科IOS误删除恢复的方法2:XMODEM
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: 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 newconfig 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 disasterrecovery.
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, RELEASESOFTWARE (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 mainmemory
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: 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 [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 newconfig 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 image
context display the context of a loadedimage
cookie display contents of cookie PROM inhex
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 systemreturn
tftpdnld tftp image download
unalias unset an alias
unset unset a monitor variable
xmodem x/ymodem image 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 disasterrecovery.
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 image :
Restricted Rights Legend
Use, duplication, or disclosure by theGovernment is
subject to restrictions as set forth insubparagraph
(c) of theCommercial Computer Software - Restricted
Rights clause at FAR sec. 52.227-19 andsubparagraph
(c) (1)(ii) of the Rights in Technical Dataand Computer
Software clause at DFARS sec. 252.227-7013.
Cisco Systems, Inc.
170 West Tasman Drive
San Jose, California 95134-1706
Cisco Internetwork Operating SystemSoftware
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
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 image
context display the context of a loadedimage
cookie display contents of cookie PROM inhex
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 systemreturn
tftpdnld tftp image download
unalias unset an alias
unset unset a monitor variable
xmodem x/ymodem image 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 disasterrecovery.
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 image :
Restricted Rights Legend
Use, duplication, or disclosure by theGovernment is
subject to restrictions as set forth insubparagraph
(c) of theCommercial Computer Software - Restricted
Rights clause at FAR sec. 52.227-19 andsubparagraph
(c) (1)(ii) of the Rights in Technical Dataand Computer
Software clause at DFARS sec. 252.227-7013.
Cisco Systems, Inc.
170 West Tasman Drive
San Jose, California 95134-1706
Cisco Internetwork Operating SystemSoftware
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
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 image
context display the context of a loadedimage
cookie display contents of cookie PROM inhex
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 systemreturn
tftpdnld tftp image download
unalias unset an alias
unset unset a monitor variable
xmodem x/ymodem image 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 disasterrecovery.
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 image :
Restricted Rights Legend
Use, duplication, or disclosure by theGovernment is
subject to restrictions as set forth insubparagraph
(c) of theCommercial Computer Software - Restricted
Rights clause at FAR sec. 52.227-19 andsubparagraph
(c) (1)(ii) of the Rights in Technical Dataand Computer
Software clause at DFARS sec. 252.227-7013.
Cisco Systems, Inc.
170 West Tasman Drive
San Jose, California 95134-1706
Cisco Internetwork Operating SystemSoftware
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 ofmemory
.
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 configurationmemory.
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 byconsole
00:00:06: %SYS-5-RESTART: System restarted --
Cisco Internetwork Operating SystemSoftware
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 onInterface Serial0/0, changed sta
te to up
00:00:07: %LINEPROTO-5-UPDOWN: Line protocol onInterface Loopback0, changed sta
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