3750X Corrupt IOS

robrobinson057 · ‎07-26-2016

Gents

An interesting issue. I've been given a 3750X switch pulled from a working environment and one of my engineers attempted to reload a new IOS onto the box. The IOS was corrupt and I'm now in a situation when the IOS partially loads and then freezes the switch. Mode button nor break keys can get the box into Rommon and the BAUD is set to 57600 as he forgot to unset BAUD following the attempt at upgrading the IOS. The only output I'm getting from the switch is as follows:

Using driver version 3 for media type 2
Base ethernet MAC Address: f0:f7:55:b1:b9:80
Xmodem file system is available.
The password-recovery mechanism is enabled.
Initializing Flash...
mifs[2]: 10 files, 1 directories
mifs[2]: Total bytes : 2097152
mifs[2]: Bytes used : 741376
mifs[2]: Bytes available : 1355776
mifs[2]: mifs fsck took 0 seconds.
mifs[3]: 0 files, 1 directories
mifs[3]: Total bytes : 4194304
mifs[3]: Bytes used : 8192
mifs[3]: Bytes available : 4186112
mifs[3]: mifs fsck took 2 seconds.
mifs[4]: 5 files, 1 directories
mifs[4]: Total bytes : 524288
mifs[4]: Bytes used : 49152
mifs[4]: Bytes available : 475136
mifs[4]: mifs fsck took 0 seconds.
mifs[5]: 5 files, 1 directories
mifs[5]: Total bytes : 524288
mifs[5]: Bytes used : 49152
mifs[5]: Bytes available : 475136
mifs[5]: mifs fsck took 0 seconds.
mifs[6]: 3 files, 3 directories
mifs[6]: Total bytes : 119144448
mifs[6]: Bytes used : 14987264
mifs[6]: Bytes available : 104157184
mifs[6]: mifs fsck took 34 seconds.
...done Initializing Flash.
done.
Loading "flash:c3750e-universalk9-mz.122-55.SE10.bin"...flash:c3750e-universalk9-mz.122-55.SE10.bin: no such file or directory

Error loading "flash:c3750e-universalk9-mz.122-55.SE10.bin"

Interrupt within 5 seconds to abort boot process.
Loading "flash:/c3750e-universalk9-mz.122-55.SE.bin"...@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@

Any suggestions?

Cheers

Leo Laohoo · ‎07-26-2016

Loading "flash:/c3750e-universalk9-mz.122-55.SE.bin"

The IOS is looks to be corrupt.

What is the exact model of this switch?

The only way to fix this is to perform the following:

1. Force the switch to boot into ROMmon;

2. Download the correct IOS (BIN & TAR file) from the Cisco website.

NOTE & IMPORTANT: Compare the MD5 hash values of the file(s) downloaded against the MD5 hash values found in the Cisco website. They have to match.

3. Find a supported USB thumb drive and format the USB thumb drive with FAT16.

4. Copy the files into the USB thumb drive.

5. Force the switch to boot the BIN file found in the USB thumb drive. The command is: boot usbflash0:

6. Once the switch has rebooted fine, instruct the switch to unpack the IOS found in the USB thumb drive. The command: archive download-sw usbflash:IOS.tar

robrobinson057 · ‎07-26-2016

Switch model is C3750-24S-S the main issue I've got is no matter what I try all I get from the switch is the output above and can't get it into ROMmon.

Leo Laohoo · ‎07-26-2016

Switch model is C3750-24S-S

Hold on ... this doesn't make sense. A plain 3750 attempting to run an IOS meant for 3750E/3750X?

can't get it into ROMmon.

Power down the switch, HOLD DOWN the Mode button. Power up the switch with the Mode button still held down. Count to 15 seconds. Release the Mode button.

robrobinson057 · ‎07-26-2016

My bad, c3750x-24s-s

tried the mode button route but no joy as per the original post.

Leo Laohoo · ‎07-26-2016

tried the mode button route but no joy as per the original post.

Play dirty:

1. Stand the 3750X on it's side where the mode button is held down by the weight of the switch.

2. Power down the switch.

3. Power up the switch.

4. Wait for about 25 seconds.

robrobinson057 · ‎07-28-2016

No joy with that solution either. I have a feeling this could be an RTM