Question : Boot Process of Cisco Router vs Computer

I've got to write a 2-3 page paper on the following subject.  Any input or direction to where I can find such information would be greatly appreciated.

Compare and Contrast the Boot Process of a Computer to that of a Cisco Router.  Include what each type of memory does on the router, and how the back-up configurations can be saved.

Answer : Boot Process of Cisco Router vs Computer

Hi,

Let me try to answer your question or atleast parts of it.

A) One of the things that you have asked is about the memory in a router. There are three types of memory in a router, each one with a different use:
1. You have a Read Only Memory (ROM). This is used to store the the BIOS and boot information such as boot sequence/location of IOS etc.

2. You have a Flash Memory. This is used to store the IOS, the Operating System for the router, as well as startup configuration files.

3. You have Random Access Memory (RAM). This where the IOS loads every time you boot the router. This is also where the running configuration file is stored.

B) About the second question "how the back-up configurations can be saved". You use the "copy" command on the router to do this. Following are the ways you can backup your router configuration:
1. First thing you can do is use the command "copy running-configuration startup-configuration". A shorter command would be "copy run start". This would save the router configuration file from the RAM/Volatile Memory to Flash/ Non-volatile Memory. A word of caution, only save the running configuration to startup configuration when you are sure that everything is working fine. Otherwise you may end up replacing a functional configuration with a non-functional.

2. Another way to save your backup configuration file is to use the command "copy run tftp", and follow the screens after that. This command is used to save the router configuration, or even the IOS for that matter to a remote location accesible from the router. This remote machine acts as a tftp server, that can be used to get the above mentioned files from in case something goes wrong with the current copies. You would have to specify the IP address of this remote machine.

3. The most simple and a really useful way I personally used to save the backup configurations was to coneect to the router from a PC using telnet, run the command, "sh run" or "sh start" depending upon the configuration file I needed to save, simply copy it using the mouse and paste it to the local PC as a tect file. This file can then be used to restore the configurration selectively in case something goes wrong with the original configuration.

C) About the boot process of the router, you can simply go to http://www.cisco.com. There is loads of information available there. in case you don't find it, ping us again, and I'll try and put relevant information up for you.

Hope this helps.

Sarang

P.S:- I haven't worked on the routers for quite some time, so my command sysntax may be a bit rusty. Kindly check it for correctness. ;-)