25網(wǎng)絡(luò)工程師交換試驗手冊之二十五：詳細講授利用xmodem來恢復(fù)IOS

1、網(wǎng)絡(luò)工程師交換試驗手冊之二十五：詳細講授利用xmodem來恢復(fù)IOS實驗?zāi)康模何覀円话阍诠ぷ髦?，?jīng)常會遇到IOS莫名其妙的丟失，有時候很突然，有時候很棘手，如果網(wǎng)絡(luò)因為你的失誤而中斷，你的責(zé)任會很重要，所以大家一定要掌握恢復(fù)IOS的方法。實驗拓撲：pc IOS丟失以后，所有的設(shè)備都會啟動最小啟動模式。rommon 1 confreg 回車 Configuration Summary enabled are: load rom after netboot fails console baud: 9600 boot: image specified by the boot system comma

2、nds or default to: Cisco2-C2600 do you wish to change the configuration? y/n n: y (選擇 yes) enable diagnostic mode? y/n n: n (選擇 no) enable use net in IP bcast address? y/n n: n (選擇 no) disable load rom after netboot fails? y/n n: n (選擇 no) enable use all zero broadcast? y/n n: n (選擇 no) enable break

3、/abort has effect? y/n n: n (選擇 no) enable ignore system config info? y/n n: n (選擇 no) change console baud rate? y/n n: y (選擇 yes) enter rate: 0 = 9600, 1 = 4800, 2 = 1200, 3 = 2400 4 = 19200, 5 = 38400, 6 = 57600, 7 = 115200 0: 7 (選擇 7,用最大的115200速率的xmodem傳輸) change the boot characteristics? y/n n:

4、n (選擇 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 (選擇 no) You must reset or power cycle for new config to take effect rommon 2

5、reset 回車 注意：在此時鍵入 reset鍵之前，開始定義串口速度（我的電腦-端口屬性-串口速度調(diào)為115200），然后再修改超級終端里設(shè)置速率為115200，記住，一定這么做！否則出現(xiàn)亂碼！ 然后關(guān)閉這個超級終端，重新建立一個超級終端連接，（期間系統(tǒng)重新啟動）啟動后，出現(xiàn) rommon 1 提示符 然后,輸入 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:

6、y (選擇 yes) Ready to receive file . 此時，在超級終端的菜單上的“傳送”-“發(fā)送文件”-選擇IOS鏡像文件所在地以及選擇使用“xmodem”協(xié)議，點擊“發(fā)送”即可 然后等待10-20分鐘左右就把3-6M的IOS灌進去了！ 需要主意的是，這是科學(xué)估算時間和實際的時間相差很遠，實際如果10幾M的話要3個多小時。希望大家預(yù)備好咖啡和甜品準備漫長的等待，本人深有體會，呵呵！ （修改回計算機串口與超級終端、路由器confreg下的xmodem等9600的傳輸速率） （videre注：實際用的時候，我發(fā)現(xiàn)這個命令總是改不成功，后來發(fā)現(xiàn)在line con 0下面有了一個spe

7、ed 115200，所以即使改register成功，啟動以后router又執(zhí)行speed 115200,還是不行，所以如果有這個問題，記得把這個語句no掉）Routeren 進入新IOS的特權(quán)模式 Router#reload 重啟系統(tǒng) Proceed with reload? confirm 回車 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:H

8、ome:SW:IOS:Specials for info PC = 0 xfff0a530, Vector = 0 x500, SP = 0 x680127b0 C2600 platform with 24576 Kbytes of main memory PC = 0 xfff0a530, Vector = 0 x500, SP = 0 x80004684 monitor: command boot aborted due to user interrupt rommon 1 confreg （ 輸入“confreg”命令） Configuration Summary enabled are

9、: 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 (選擇 yes) enable diagnostic mode? y/n n: n (選擇 no) enable use net in IP bcast address? y/n n: n (選擇 no) disable load rom

10、after netboot fails? y/n n: n (選擇 no) enable use all zero broadcast? y/n n: n (選擇 no) enable break/abort has effect? y/n n: n (選擇 no) enable ignore system config info? y/n n: n (選擇 no) change console baud rate? y/n n: y (選擇 yes) enter rate: 0 = 9600, 1 = 4800, 2 = 1200, 3 = 2400 4 = 19200, 5 = 38400

11、, 6 = 57600, 7 = 115200 7: 0 (選擇 0,改回用標(biāo)準速率速率9600的xmodem傳輸) change the boot characteristics? y/n n: n (選擇 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 conf

12、iguration? y/n n: n You must reset or power cycle for new config to take effect rommon 2 此時手工改回計算機串口與超級終端2者傳輸速率為9600 然后敲入 rommon 2 reset ( 最好關(guān)電源) 然后關(guān)閉這個超級終端，重新建立一個超級終端連接，一切就OK了通過Xmodem升級2610的IOS實例 如果你不小心使用了命令erase flash 那么發(fā)生什么就可想而知了。因此，建議在你拿到路由器等網(wǎng)絡(luò)設(shè)備時 最好先將它的IOS等操作系統(tǒng)備份出來，以備萬一！本篇主要介紹通過Xmodem上傳IOS的過程（以

13、2610為例，不過這個方法用在其他設(shè)備上沒什么太大區(qū)別）準備工作，只要有Cisco原配的線纜就可以（注：Xmodem與實際的modem沒有任何聯(lián)系 只是一個傳輸協(xié)議 數(shù)據(jù)是通過終端的串口和路由器的Console口灌進去的）在沒有IOS的情況下 系統(tǒng)只能進入Rommon狀態(tài)，在這個狀態(tài)下只能見到如下命令：rommon 8 ?alias set and display aliases commandboot boot up an external processbreak set/show/clear the breakpointconfreg configuration register uti

14、litycont continue executing a downloaded imagecontext display the context of a loaded imagecookie display contents of cookie PROM in hexdev list the device tabledir list files in file systemdis display instruction streamdnld serial download a program moduleframe print out a selected stack framehelp

15、monitor builtin command helphistory monitor command historymeminfo main memory informationrepeat repeat a monitor commandreset system resetset display the monitor variablesstack produce a stack tracesync write monitor environment to NVRAMsysret print out info from last system returntftpdnld tftp ima

16、ge downloadunalias unset an aliasunset unset a monitor variablexmodem x/ymodem image download在這個模式下，輸入Xmodemrommon 9 xmodem會提示如下警告：WARNING: All existing data in bootflash will be lost!Invoke this application only for disaster recovery.Do you wish to continue? y/n n: yReady to receive file ? .然后在超級終端

17、的傳送欄目= 選擇發(fā)送選項 = 再選擇Xmodem 并指明IOS所在的路徑即開始上傳IOS,等待時間很長，視IOS的大小和傳輸速度。對于初次做IOS上傳，建議不要去修改什么傳輸速率。傳完以后 對整個系統(tǒng)初始化 界面如下：Erasing flash at 0 x603c0000program flash location 0 x602f0000Download Complete!program load complete, entry point: 0 x80008000, size: 0 x2f0074Self decompressing the image : # OKRestricted

18、Rights LegendUse, duplication, or disclosure by the Government issubject to restrictions as set forth in subparagraph(c) of the Commercial Computer Software - RestrictedRights clause at FAR sec. 52.227-19 and subparagraph(c) (1) (ii) of the Rights in Technical Data and ComputerSoftware clause at DFA

19、RS sec. 252.227-7013.Cisco Systems, Inc.170 West Tasman DriveSan Jose, California 95134-1706Cisco Internetwork Operating System SoftwareIOS (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 ccaiImage

20、 text-base: 0 x80008084, data-base: 0 x80554578Cisco 2610 (MPC860) processor (revision 0 x202) with 12288K/4096K bytes of memory.Processor board ID JAB0233005Z (3677578902)M860 processor: part number 0, mask 32Bridging software.X.25 software, Version 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 up00:00:06: %LINK-3-UPD