CCNA 006 管理路由器.pptx

管理路由器
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
ROM 功能
ROM
存放完成基本功能的微代码
ROM monitor 类似Windows的安全模式
Mini IOS在多数高端设备中已取消
Bootstrap
Mini IOS
ROMmonitor
POST
show version
控制台
确认当前的配置寄存器值
wg_ro_a#show version
Cisco work Operating System Software
IOS (tm) 2500 Software (C2500-JS-L), Version (3), RELEASE SOFTWARE (fc1)
Copyright (c) 1986-1999 by cisco Systems, Inc.
Compiled Mon 08-Feb-99 18:18 by phanguye
Image text-base: 0x03050C84, data-base: 0x00001000
ROM: System Bootstrap, Version (10c), SOFTWARE
BOOTFLASH: 3000 Bootstrap Software (IGS-BOOT-R), Version (10c), RELEASE SOFTWARE (fc1)
wg_ro_a uptime is 20 minutes
System restarted by reload
System image file is "flash:c2500-js-l_120-"
--More--
Configuration register is 0x2102
用命令show version所显示的配置寄存器值
配置寄存器的3, 2, 1和0位是启动选项位
设定配置寄存器的值
配置寄存器
启动选项部分的值
0x0
0x2 to 0xF
0x1
含义
进入ROM monitor模式
(人工启动时用 ctrl+break 命令)
检查NVRAM之 boot system 命令(如果路由器配有Flash则缺省值为 0x2)
自动从ROM启动
(提供完整IOS的一个子集,miniIOS)
Router#configure terminal
Router(config)#config-register 0x2102
[Ctrl-Z]
Router#reload
路由器启动流程图
Use IOS fromFlash
Attempt to get
IOS work
Use IOS in ROM
(RXBoot mode)
Check start-up
config
Boot field =0
0x0
Boot field =1
0x1
Boot mands?
Config regbit 13=1?
5 failures?
Valid IOS inFlash?
Do what
they say
Run
ROM Monitor
START
Yes
Yes
No
No
Yes
No
No
Yes
Yes
No
No
Yes
ess?
No
Yes
Use file work
Load IOS
Valid config
?
Config regbit 6=1?
Yes
No
Yes
SETUP
DIALOG
NORMAL
START PLETE
No
Router#erase start
Erasing the nvram filesystem will remove all configuration files! Continue? [confirm]
[OK]
Erase of nvram: complete
%SYS-7-NV_BLOCK_INIT: Initialized the geometry of nvram
wg_ro_a#show flash
System flash directory:
File Length Name/status
1 10084696 c2500-js-l_120-
[10084760 bytes used, 6692456 available, 16777216 total]
16384K bytes of processor board System flash (Read ONLY)
清空所有配置
查看flash
wg_ro_