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Upgrade Memory and Flash 3600 series!!

Level 5
Level 5

I have to do it b4 I totally understand.

we have 3640 with 64Memory/16Flash(internal).

We are going to upgrade to 96/32.

Let's say we are going to take out all old memeory and flash.

First, I try to understand is that the New Flash has no IOS image in it. We have to use "Xmodem Console download porcedure using ROMmon, right???

For Memory, just make sure the copy running configure to TFTP first, after upgrading from 64 to 96, we can always copy back to new memory. Am I right?

One more question, is there any command to find out the bank(memory slot) is ocuppied or not??


7 Replies 7


you are right, you will have to use XMODEM in ROMMON mode to load the IOS onto flash.

If you have PCMCIA flash card, you can also load an IOS (or the IOS currently loaded in your router, provided the flash card has enough memory) onto the flash card, insert the flash card after the memory upgrade, and then use the normal TFTP download procedure.

You are also right regarding the IOS you want to save, copy it to a TFTP server first and then back onto the router after the upgrade.

You might want to check this document:


ROMmon Recovery for the Cisco 3600 Series Router



Anyone can answer my 3rd question?

Is there any command to find out the bank(memory slot) is ocuppied or not??


Yes, here is a link that explains how to find out how to determine the SIMM configuration on the 3620 and 3640.

I hope this helps.

Thanks for help. It is very helpful.

How about Flash configuration?? Can we find out without opening the case??


Well, to make sure you will have to open the case. But, according to next document, if you ordered this router with 16 MB Flash, it should be shipped with a configuration using 2 slots with 8 MB SIMM at each one as that is the Flash Standard Factory Option.

See 'Table 10' at next document:


I don't think that the document you linked is correct. I have several 3640s that were ordered with 16MB of flash and they all had (had because I just installed a 16MB flash SIMM) one 16MB flash SIMM.

Great link on finding out the memory config, BTW. I just wish I had it when I was going about upgrading all my 3640s... ;)

Level 1
Level 1

Can anyone supply a link that actually works for the PDF version of the "Upgrading System Memory in Cisco 3600 Series Routers" document? CCO just gives 404 error for both HTML and PDF versions of this document. Can't seem to find it anywhere on the Web. Thanks.