12-21-2019 03:18 AM
Hi
Recently my team and I were trying to update the IOS on catalyst 3750 and 3850 switches and they ran into the problem of the switches not taking the IOS at all. We even tried using xmodem and somehow it made them worse. Now the switches are showing scribbles, as in letters, symbols and numbers all mixed up. We tried using the usb boot up way but the switches won't take the IOS as well.
We're not sure if that's fixable or not.
12-21-2019 04:28 AM
12-21-2019 07:29 AM
sorry for the inconvenience, because we had the switches sent to other team to fix so I can't give you exactly what happened but I can only give you what I remember when it finishes booting:
switch: set
ln34^fgfghj436S%$75oi88$#%tHru56TSh54o89j(JOjour tjoJIGo4j3y9 JFOKYPTU9&*pie978277H&3$%^&*{:>kdfGFDSP:>Llfghjh;><KJfGJHKl;@#$%%^&5=--9dsfojhithsb&*()8343mfdsh&^y349u98hv3y5*^55688hgj1dc"{?";er5Gh68hS1246Dfry54N6 ery586
switch: dir
xmodem[0]: (read-only)
null[1]: (read-write)
bs[3]: (read-only)
flash[18]: (read-only)
tftp[19]: (read-write)
switch:
I tried setting the baud rate to 9600 or 115200 but every time it's always like this...and this happens after I used the xmodem to load the IOS
12-21-2019 12:37 PM
what kind of terminal software you using ? is this fixed after loading IOS?
12-21-2019 02:51 PM
12-21-2019 06:01 PM
We tried TeraTerm, Putty and SecureCrt
And we tried using different thumb drives and sometimes the switches can't even read them
when they're able to read the thumb drives and we tried to upload the IOS or boot from it it'll show
Loading usbflash0:(IOS name) bad file number
or
usbflash0: contains unexpected values in partition table or boot sector
for now using the thumb drives is the only way we can think of to load the IOS
12-22-2019 12:08 AM
12-23-2019 11:41 AM
Is the thumb drive over 4GB? Because that can cause issues
12-23-2019 01:13 PM
@Justin S wrote:
Is the thumb drive over 4GB? Because that can cause issues
Not necessarily true.
I have a Samsung 16Gb thumb drive and it works well with routers and switches (including supervisor cards).
12-24-2019 12:30 AM
12-24-2019 12:52 AM
here is the steps to fix.
1. From ROMMON - Boot from your 32GB SD CARD.
2. Once boot proces completed. and you have # prompt in cisco device.
3. Copy the cisco image from 32GB SD Card to flash :
4. Delete if any old image in the flash : , issue dir flash: show you old .bin image file
you want to delete - delete flash:image.bin (example)
5. check the boot parameter by issuing - show boot
copy boot variable and remove the boot variable by issue command below
no boot system:oldimage.bin
setup a new boot image
boot system flash:newimage.bin
write
check again make sure boot image correct show boot.
if all good.
6. reload the switch.
7. now the switch should boot automatically with new image.
if not - connect the console and post complete boot process to understand
Good luck.
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