路由器的组件与启动流程.ppt

路由器基础功能介绍,路由器启动顺序,执行POTS加电自检 加载并运行启动程序代码 查找IOS软件 加载IOS软件 查找配置 加载配置 运行配置过的IOS,路由器内部组件,ROM 功能,MINI IOS操作系统包含了路由器基本功能的微代码,配置寄存器值,启动位由4位16进制寄存器组成 格式：0xABCD 赋值范围从0x0到0xFFFF 0x2102 ：工业默认值 0x2142 ：从FLASH中启动，但不使用NVRAM中的配置文件（用于口令恢复） 0x2101 ：从Boot RAM中启动，应用于更新系统文件 0x2141 ：从Boot RAM中启动，但不使用NVRAM中的配置文件,查找IOS镜像,查找顺序: 1. 检查寄存器值 2. 查看boot system命令配置 3. 默认情况下调用Flash中的第一个文件 4. 尝试从网络服务器启动 5. 启动帮助镜像 6. ROMMON,从Flash中加载IOS镜像,Flash中的镜像文件被加载到RAM中,加载配置文件,加载并执行NVRAM中的配置文件 如果NVRAM中没有配置文件进入配置模式,显示当前和保存的配置,show running-config and show startup-config 命令,确定当前配置寄存器值,Cisco IOS Software, 2800 Software (C2800NM-IPBASE-M), Version 12.4(5a), RELEASE SOFTWARE (fc3) Technical Support: /techsupport Copyright (c) 1986-2006 by Cisco Systems, Inc. Compiled Sat 14-Jan-06 03:19 by alnguyen ROM: System Bootstrap, Version 12.4(1r) hqluong 1r, RELEASE SOFTWARE (fc1) RouterX uptime is 1 week, 5 days, 21 hours, 30 minutes System returned to ROM by reload at 23:04:40 UTC Tue Mar 13 2007 System image file is “flash:c2800nm-ipbase-mz.124-5a.bin“ Cisco 2811 (revision 53.51) with 251904K/10240K bytes of memory. Processor board ID FTX1013A1DJ 2 FastEthernet interfaces 2 Serial(sync/async) interfaces DRAM configuration is 64 bits wide with parity enabled. 239K bytes of non-volatile configuration memory. 62720K bytes of ATA CompactFlash (Read/Write) Configuration register is 0x2102,show version 命令,Cisco IOS Software, 2800 Software (C2800NM-IPBASE-M), Version 12.4(5a), RELEASE SOFTWARE (fc3) Technical Support: /techsupport Copyright (c) 1986-2006 by Cisco Systems, Inc. Compiled Sat 14-Jan-06 03:19 by alnguyen ROM: System Bootstrap, Version 12.4(1r) hqluong 1r, RELEASE SOFTWARE (fc1) RouterX uptime is 1 week, 5 days, 21 hours, 30 minutes System returned to ROM by reload at 23:04:40 UTC Tue Mar 13 2007 System image file is “flash:c2800nm-ipbase-mz.124-5a.bin“ Cisco 2811 (revision 53.51) with 251904K/10240K bytes of memory. Processor board ID FTX1013A1DJ 2 FastEthernet interfaces 2 Serial(sync/async) interfaces DRAM configuration is 64 bits wide with parity enabled. 239K bytes of non-volatile configuration memory. 62720K bytes of ATA CompactFlash (Read/Write) Configuration register is 0x2102 (will be 2104 at next reload),show flash 命令,RouterX#sh flash -#- -length- -date/time- path 1 14951648 Feb 22 2007 21:38:56 +00:00 c2800nm-ipbase-mz.124-5a.bin 2 1823 Dec 14 2006 08:24:54 +00:00 sdmconfig-2811.cfg 3 4734464 Dec 14 2006 08:25:24 +00:00 sdm.tar 4 833024 Dec 14 2006 08:25:38 +00:00 es.tar 5 1052160 Dec 14 2006 08:25:54 +00:00 common.tar 6 1038 Dec 14 2006 08:26:08 +00:00 home.shtml 7 102400 Dec 14 2006 08:26:22 +00:00 home.tar 8 491213 Dec 14 2006 08:26:40 +00:00 128MB.sdf 41836544 bytes available (22179840 bytes used),总结,路由器启动过程中, 需要执行自检，查找和加载IOS软件,查找和加载配置文件,最终运行IOS. 主要的路由器内部组件包括RAM, ROM, flash memory, NVRAM, 和 configuration registe