Cannot boot 3600 router

[jacquesd]

Hi All,

I have a 3640 which has two images in the flash. The first image has a problem, and the router hangs after decompressing the image. The second image boots, but due to a configuration problem, continuously recycles the router (I cannot even get to the password screens - it reboots before that).

When I use confreg 0x2142, it tries to boot the first image, which does not work. Is there a way to get rid of this image from ROMMON?

Thanks

Jacques

[olorunloba]

Using xmodem form rommon will delete the exsiting images on the flash. What you could is to copy the image you want to use, using the xmodem, this will now be the only image in the flash.

[jacquesd]

Hi,

Unfortunately the only other image I have available is too big for the flash. But thanks anyway, you pointed me in the right direction.

Jacques

[ramirogarza]

I assume you are using 0x2142 to bypass NVRAM and hence be able to boot the good image without it recycling the router due to the config problem you have, but it keeps booting up with the image that doesn't work. I suggest you use the boot command in rommon to force the router to boot with the image you want it to boot with.Check the following link:

http://www.cisco.com/en/US/products/hw/routers/ps274/products_tech_note09186a008009429f.shtml

[jacquesd]

Hi,

I eventually came right by using confreg in rommon on its own without a value. It turns out confreg creates a value of 0x2141 instead of 0x2142. It looks like the 3640 uses different values (??) in the configuration register. I think I read that there is no RXBoot on a 3640, which 0x2141 should do. (correct me if i am wrong).

Thanks

Jacques

[ramirogarza]

Hi,

You are right about one thing, 0x2141 boots some routers with the boot helper image but the 36x0 routers don't have a boot flash, hence it won't do it. if you take a look at the document on the following link http://www.cisco.com/en/US/products/hw/routers/ps274/products_installation_guide_chapter09186a008007de4c.html#23183

You'll see that 0x2141 should load the first image in flash as a sytem image.

As for confreg creating a value of 0x2141 instead of 0x2142 when you issue it without a value, well, that depends on what option you select during this part of confregs menu:

change the boot characteristics? y/n [n]: y

enter to boot:

0 = ROM Monitor

1 = the boot helper image

2-15 = boot system

[0]:

if you select "2" you should end up having a confreg of 0xXXX2 not 0xXXX1.

Hope this answered your question.

Regards

Ramiro Garza

[jacquesd]

Hi,

I chose not to change the boot characteristics, but to ignore NVRAM, which ended up with 0x2141. But anyway, all is well now (except that I cannot install a WIC2T card because my IOS will not recognise it (11.3) and version 12.1+ requires more memory than in the router - had to install 2 x WIC1T). Thanks all for replying.

Jacques

[billtoth]

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