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Flash

i am just confude abt one thing......i have couple of routers and when i put the command show version.....in many routers i get 16000 (read only) and some i get read/write) only...can someone plz tell me whats the difference

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Re: Flash

Hi Guroo,

I think you are talking about 2500 series routers in which if you do "sh version" you will see 16 MB of read only memory? If I am correct the 25xx platforms that do not have on-board DRAM and only use SIMMs.

The 2500 routers run the Cisco IOS software from Flash. These image files are defined as

re-locatable, because the Cisco IOS software image can be executed from different locations in the Flash.

A re-locatable image file is recognized by the letter "l" contained in the file name (for instance: c2500-js-l.121-9). As a consequence, the Flash memory is set as read only when the main Cisco IOS software is running.

In other routers like 3600 etc etc there is a seperate DRAM and Flash and when router loads the IOS the IOS get loaded in DRAM which is not in the case of 2500 series router where IOS gets booted from flash itself.

HTH

Ankur

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