cisco ccna 认证考试 管理网络环境.ppt

管理网络环境 Cisco设备的简单启动过程 路由器加电/启动顺序 加电自检 (POST) 加载并运行启动引导微代码 寻找IOS映象文件 加载IOS映象文件 寻找配置文件 加载配置文件 正常运行 路由器内部组件 内存体系 RAM:动态随机存取储器，运行配置或活动配置文件保存这里。开机时解压到此！ ROM：用来引导IOS映像。 FLASH：存储了功能完备的IOS映像文件。 NVRAM：非易失性随机存取存储器存储了初始或启动配置文件。 除RAM以外，所有这些类型的存储器都是永久性存储器。 ROM 功能 寻找IOS映象文件 确认当前的配置寄存器值 设定配置寄存器的值 配置寄存器的3, 2, 1和0位是启动选项位 用命令show version来检查配置寄存器的值 从Flash加载IOS映象文件 使用 show flash 命令 加载配置文件 使用 show running 和 show startup 命令 配置参数的来源 配置参数的来源 使用copy run tftp 和 copy tftp run 命令 Cisco文件系统与设备 管理IOS映象文件 映象文件备份的准备 映象文件备份的准备 映象文件备份的准备 映象文件备份的准备 确认存贮空间并解析文件名 作映象文件的备份 从网络升级IOS Slide 1 of 1 Purpose: Emphasize: Note: Mini IOS is the Rxboot mode. One use of the Rom Monitor is for password recovery. From Rom Monitor, you can set the config register to 0x2142 so the NVRAM will be ignored during startup. Slide 1 of 1 Purpose: Emphasize: Note: There is a detail flowchart of the router startup process on the next slide. Slide 1 of 1 Purpose: Emphasize: Use the show version command to display the value of the Config register setting. When you change the config register, we will see from the show version output: Configuration register is 0x2102 (will be 0x2142 at next reload). The new config register value will be used at the next reload. Slide 4 of 4 Purpose: Emphasize: Layer 4—Finishes with the third case, a boot field setting in the range of 0x2 to 0xF. The entry of a Configuration Register value in the 0x2 to 0xF range is significant. When the router attempts to boot from the net (Netboot), the bootstrap program generates an IOS filename based on the value of the boot field. For example, with the setting 0x2, the default IOS filename generated will be cisco2-xxxx, where xxxx refers to a processor name (for example, 2500). Again, refer students to the IMCR course for details. You use the config-register command to change the value. Notice that the bottom lines of the show version output indicates what the value the config register will be on the next reload. Slide 1 of 1 Purpose: