Router Startup and Configuration Management

© 2002, Cisco Systems, Inc. All rights reserved.
© 2002, Cisco Systems, Inc. All rights reserved.
2
Router Startup and Configuration Management
Objectives
Upon completing this lesson, you will be able to:
Describe the router boot sequence and explain how to verify that the router booted correctly
Identify the internal components of Cisco switches and routers
Router Power-On/Bootup Sequence
Perform power-on self test (POST).
Load and run bootstrap code.
Find the Cisco IOS software.
Load the Cisco IOS software.
Find the configuration.
Load the configuration.
Run the configured Cisco IOS software.
Router Internal Components
ROM Functions
Contains microcode for basic functions
Finding the
Cisco IOS Software
Router Startup Flowchart
Loading the Cisco IOS Software
from Flash Memory
The flash memory file is decompressed into RAM.
Loading the Configuration
Load and execute the configuration from NVRAM.
If no configuration is present in NVRAM, enter setup mode.
Determining the Current Configuration Register Value
wg_ro_a#show version
Cisco Internetwork Operating System Software
IOS (tm) 2500 Software (C2500-JS-L), Version 12.0(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 11.0(10c), SOFTWARE
BOOTFLASH: 3000 Bootstrap Software (IGS-BOOT-R), Version 11.0(10c), RELEASE SOFTWARE (fc1)

wg_ro_a uptime is 20 minutes
System restarted by reload
System image file is "flash:c2500-js-l_120-3.bin"

--More--

Configuration register is 0x2102


Configuration register value in show version
Configuration register bits 3, 2, 1, and 0 set boot option.






Check the configuration register value with show version.
Configuration Register Values
show version Command
Router#show version
Cisco Internetwork Operating System Software
IOS (tm) C2600 Software (C2600-JS-M), Version 12.0(7a), RELEASE SOFTWARE (fc1)
Copyright (c) 1986-2002 by cisco Systems, Inc.
Compiled Tue 05-Feb-02 01:48 by pwade
Image text-base: 0x80008088, data-base: 0x80B0404C

ROM: System Bootstrap, Version 11.3(2)XA4, RELEASE SOFTWARE (fc1)

Router uptime is 1 minute
System restarted by reload
System image file is "flash:c2600-js-mz.120-7a.bin"

cisco 2610 (MPC860) processor (revision 0x300) with 53248K/12288K bytes of memory.
Processor board ID JAD06090BMD (2719249260)
M860 processor: part number 0, mask 49
Bridging software.
X.25 software, Version 3.0.0.
SuperLAT software (copyright 1990 by Meridian Technology Corp).
TN3270 Emulation software.
Basic Rate ISDN software, Version 1.1.
1 Ethernet/IEEE 802.3 interface(s)
2 Serial(sync/async) network interface(s)
1 ISDN Basic Rate interface(s)
32K bytes of non-volatile configuration memory.
16384K bytes of processor board System flash (Read/Write)

Configuration register is 0x2102


show flash Command
wg_ro_a#show flash

System flash directory:
File Length Name/status
1 10084696 c2500-js-l_120-3.bin
[10084760 bytes used, 6692456 available, 16777216 total]
16384K bytes of processor board System flash (Read ONLY)


show running-config and
show startup-config Commands
wg_ro_c#show startup-config
Using 1359 out of 32762 bytes
!
version 12.0
!
-- More --
wg_ro_c#show running-config
Building configuration...

Current configuration:
!
version 12.0
!
-- More --
In NVRAM
In RAM
Displays the current and saved configuration
Summary
When a router boots, it performs tests, finds and loads software, finds and loads configurations, and finally runs the software.
The major internal components of a router include RAM, ROM, flash memory, NVRAM, and the configuration register.
When a router boots, it searches for the IOS software image in a specific sequence: location specified in the configuration register, flash memory, a TFTP server, and ROM.
The configuration register includes information specifying where to locate the Cisco IOS software image. You can examine the register with a show command and change the register value with the config-register global configuration command.