Booting process of Router
Similar to the computer, a router uses a process to boot. It includes testing the hardware, loading the IOS, performing the configuration commands in the startup configuration file. The process is following:
Post-It is process used to test the router hardware. When the router powered on, post operation is starts. After the post has been completed the router executes the bootstrap program.
Bootstrap
After the post operation the boot strap program is copied from ROM into RAM. The main task of the bootstrap program is to locate the Cisco IOS and load it into the RAM. In the Bootstrap program router search the configuration register value
If the value is 0×2102(default value)
1. The bootstrap program is responsible for locating the Cisco IOS and copying it into the RAM. The IOS is typically stored in flash memory, but it can be stored in other places such as TFTP server.
2. After the IOS is loaded, the bootstrap program search for the startup configuration file, known as start up-config file in the NVRAM and this file save interface address, routing information, passwords and other configuration saved by the network administrator. If the start up-configuration file start up-config, is located in NVRAM, it is copied into RAM as the running configuration, running -config.
If the value of configuration register is 0×2142(use for password recovery):
1. Router will load the IOS from flash memory into the RAM.
2. Rorter will skip NVRAM file.
If the router boot up via 0X2142 then it will display statement
‘Would you like to enter initial configuration dialogue?’ Y/N
Press N to get the command line.
Verifying the router boot up process-
The show version command is used to help verify and troubleshoot of the basic hardware and software components of the router. This command displays information about version of the Cisco IOS, version of bootstrap program, system memory information, configuration register value etc.This command is run in the privilege mode-
Router# show version
Access the Router console-
To get the router console use the following way-
Start –Program-Accesseries-Communicaiton –Hyperlink
Then give any name and select the com port then ok on the restore default.
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