Packet Tracer 是由Cisco公司发布的一个辅助学习工具，为学习CCNA课程的网络初学者去设计、配置、排除网络故障提供了网络模拟环境。学生可在软件的图形用户界面上直接使用拖曳方法建立网络拓扑，软件中实现的IOS子集允许学生配置设备；并可提供数据包在网络中行进的详细处理过程，观察网络实时运行情况。
1. 案例目标
通过本案例，你可以掌握如下技能：1) 备份Cisco IOS2) 恢复Cisco IOS3) 备份启动配置与运行配置4) 恢复启动配置与运行配置
思科路由器交换机模拟软件(Cisco packet tracer) V5.3.0.0088 汉化最新版
2. 设备与拓扑
设备：1台 Laptop-PT，1台Server-PT ，1 台2811路由器。拓扑：如下图。
3. 操作步骤
步骤1：按以上拓扑添加和连接设备。步骤2：配置路由器与服务器的 IP 地址Router#configure terminalR1(config)#interface FastEthernet0/1R1(config-if)#ip address 192.168.1.1 255.255.255.0R1(config-if)#注意，服务器的 IP 地址可使用IP 配置 进行配置，简单快捷。
步骤3：验证路由器与服务器之间的连通性R1#ping 192.168.1.5Type escape sequence to abort.Sending 5, 100-byte ICMP echos to 192.168.1.5, timeout is 2 seconds:!!!!!Success rate is 100 percent (5/5), round-trip min/avg/max = 31/31/32 msR1#步骤4：查看路由器flash中的Cisco IOS 镜像R1#shflash:Systemflashdirectory:File Length Name/status3 50938004 c2800nm-advipservicesk9-mz.124-15.T1.bin2 28282 sigdef-category.xml1 227537 sigdef-default.xml[51193823 bytes used, 12822561 available, 64016384 total]63488K bytes of processor board Systemflash(Read/Write)R1#//注意Cisco IOS 镜像的大小与文件名
步骤5：备份Cisco IOS 到TFTP 服务器R1#copy flash: tftp:Source filename []? c2800nm-advipservicesk9-mz.124-15.T1.binAddress or name of remote host []? 192.168.1.5 //TFTP 服务器地址Destination filename [c2800nm-advipservicesk9-mz.124-15.T1.bin]?Writingc2800nm-advipservicesk9-mz.124-15.T1.bin…!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!………[OK - 50938004 bytes]50938004 bytes copied in 27.828 secs (1830000 bytes/sec)R1#步骤6：在TFTP 服务器上验证备份打开服务器的 配置 页面，单击 TFTP 按钮，可见右边窗口已有备份的Cisco IOS 镜像。
步骤7：从TFTP 服务器恢复（升级）CiscoIOS假如TFTP 服务器上要想恢复或升级的 Cisco IOS 镜像是：c2800nm-ipbase-mz.123-14.T7.binR1#copy tftp: flash:Address or name of remote host []? 192.168.1.5 //TFTP 服务器地址Source filename []? c2800nm-ipbase-mz.123-14.T7.binDestination filename [c2800nm-ipbase-mz.123-14.T7.bin]?accessing tftp://192.168.1.5/c2800nm-ipbase-mz.123-14.T7.bin…Loading c2800nm-ipbase-mz.123-14.T7.bin from192.168.1.5: !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!![OK - 5571584 bytes]5571584 bytes copied in 3.268 secs (390641 bytes/sec)R1#步骤8：验证恢复或升级R1#sh flash:System flash directory:File Length Name/status3 50938004 c2800nm-advipservicesk9-mz.124-15.T1.bin6 5571584 c2800nm-ipbase-mz.123-14.T7.bin2 28282 sigdef-category.xml1 227537 sigdef-default.xml[56765407 bytes used, 7250977 available, 64016384 total]63488K bytes of processor board System flash (Read/Write)R1#步骤9：验证NVRAM 中的启动配置和运行配置R1#dir nvram:Directory of nvram:/238 -rw- 490startup-config490 bytes total (237588 bytes free)R1#//注意启动配置的文件名及其长度。R1#sh runBuilding configuration…Current configuration : 548 bytes //运行配置的长度………R1#R1#sh startUsing 548 bytes //启动配置的长度!version 12.3………R1#步骤10：备份启动配置与运行配置1) 备份启动配置R1#copy startup-config tftp:Address or name of remote host []? 192.168.1.5Destination filename [R1-confg]? www.wusoft.net r1startupWriting startup-config…!![OK - 548 bytes]548 bytes copied in 0.062 secs (8000 bytes/sec)R1#2) 备份运行配置R1#copy running-config tftp:Address or name of remote host []? 192.168.1.5Destination filename [R1-confg]?www.wusoft.net r1runWriting running-config…!![OK - 548 bytes]548 bytes copied in 0.063 secs (8000 bytes/sec)R1#3) 在TFTP 服务器上验证备份打开服务器的配置 页面，单击TFTP 按钮，可见右边窗口已有备份的启动和运行配置。
步骤11：恢复启动配置与运行配置1) 恢复到启动配置R1#copy tftp: startup-configAddress or name of remote host []? 192.168.1.5Source filename []?www.wusoft.net r1startupDestination filename [startup-config]?Accessing tftp://192.168.1.5/R1-startup-config…Loading R1-startup-config from 192.168.1.5: ![OK - 548 bytes]548 bytes copied in 0.032 secs (17125 bytes/sec)R1#2) 恢复到运行配置R1#copy tftp: running-configAddress or name of remote host []? 192.168.1.5Source filename []?www.wusoft.net r1runDestination filename [running-config]?Accessing tftp://192.168.1.5/R1-running-config…Loading R1-running-config from 192.168.1.5: ![OK - 548 bytes]548 bytes copied in 0.031 secs (17677 bytes/sec)R1#
