IOS checksum error...

When I boot my 3640 router this is what happening...(message below)..then after 2 tries it goes to ROM monitor mode This is when I use c3640-jk9o3s-mz.124-5a ios or c3640-jk9o3s-mz.

123-13b ios. Ive reinstalled ios many times. But when I use c3640-is56-mz.112-21.P ios it doesnt create any problem. How can I solve this...I also took out ram and flash and cleaned it but no use....

Any solution I can have...

----------------------------------------------------------------------------------------------------------------------------------------- System Bootstrap, Version 11.1(20)AA2, EARLY DEPLOYMENT RELEASE SOFTWARE (fc1) Copyright (c) 1999 by cisco Systems, Inc. C3600 processor with 131072 Kbytes of main memory Main memory is configured to 64 bit mode with parity disabled

program load complete, entry point: 0x80008000, size: 0x1b84974 Self decompressing the image : ############################################################################################################################################################################################################################################################################################################################ [OK]

Error : uncompressed image checksum is incorrect 0x90C3C8F1 Expected a checksum of 0xA8C3FACD

*** System received a Software forced crash *** signal= 0x17, code= 0x9, context= 0x8000eb60 PC = 0x800080d4, Cause = 0x20, Status Reg = 0x3041f003

System Bootstrap, Version 11.1(20)AA2, EARLY DEPLOYMENT RELEASE SOFTWARE (fc1) Copyright (c) 1999 by cisco Systems, Inc. C3600 processor with 131072 Kbytes of main memory Main memory is configured to 64 bit mode with parity disabled

Reply to
Jinesh
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Clear the memory, redownload the image, check the checksum on the download (Cisco provides the checksum I thought), transfer to the memory, modify the boot statement, reboot.

Reply to
Trendkill

Clear the memory by which command Im now in rom monitor mode ....or should I install the working ios thanks for ur help

Reply to
Jinesh

I think its something like 'delete flash'.

Reply to
Trendkill

Delete command is not there in flash and actually there is nothing in flash to delete bcoz I install new ios everytime sono chance there... is there any other way...

Reply to
Jinesh

I wouldn't worry about it. Just redownload the image to your workstation, check the checksum (make sure its valid at that point), the resend to the flash. Not sure what you are using, but I have experienced issues with checksum issues with some file transfer servers, so you may need to swap your app out.

Reply to
Trendkill

This message is the result of corrupt images on the router.

When you download the IOS image from Cisco there are various checksums and the file length shown on the download page. MD5 is the easiest since there is only one.

formatting link
has a windows md5.exe and unix source code. (website is that of John Walker co-founder of Autodesk and I regard it as reliable.)

You can compare the MD5 produced by the md5 program with the MD5 that cisco publish to determine if you have a good image.

Obviously checking the length first is a decent idea.

The usual cause of corrupt images is failure to specify binary mode when transferring files by ftp, or I suppose interrupted transfers.

If you suspected a problem with the flash you could try a format of it. You can also tftpboot the router without the image on the flash.

When you have copied the image to the router you can check the image's integrity with

verify

Each image has a checksum stored internally and the router will re-compute the checksum and compare it with the stored one.

Reply to
bod43

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