Difference between revisions of "Recovering from a corrupt IOS image"
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Flow control: None | Flow control: None | ||
| − | 2. If the switch is not already at the '''switch:''' prompt, remove the power cord. Hold down the '''MODE''' button on the front of the switch and re-insert the power cord. | + | 2. If the switch is not already at the '''switch:''' prompt, remove the power cord. Hold down the '''MODE''' button on the front of the switch and re-insert the power cord. Wait until the '''SYST''' light is flashing away and let go of the '''MODE''' button. |
| + | |||
| + | 3. You should be at the '''switch:''' prompt. Type the following commands: | ||
| + | |||
| + | switch: flash_init | ||
| + | switch: load_helper | ||
| + | |||
| + | 4. List the contents of the switches flash memory | ||
| + | |||
| + | switch: '''dir flash:''' | ||
| + | Directory of flash:/ | ||
| + | |||
| + | 2 -rwx 10761792 <date> c3750-k9-mz.122-44.se2.bin | ||
| + | 3 -rwx 676 <date> vlan.dat | ||
| + | 4 -rwx 7807 <date> config.backup | ||
| + | 83 -rwx 98 <date> private-config.text | ||
| + | 86 -rwx 1048 <date> multiple-fs | ||
| + | |||
| + | 5113856 bytes available (10885120 bytes used) | ||
| + | |||
| + | 5. If there is no room in flash for another IOS image, delete the old one: | ||
| + | |||
| + | switch: '''delete flash:c3750-k9-mz.122-44.se2.bin''' | ||
| + | Are you sure you want to delete "flash:c3750-k9-mz.122-44.se2.bin" (y/n)?'''y''' | ||
| + | File "flash:c3750-k9-mz.122-44.se2.bin" deleted | ||
| + | |||
| + | 6. To speed the xmodem transfer up, change the Baud rate of the switch | ||
| + | |||
| + | switch: '''set BAUD 115200''' | ||
| + | |||
| + | You will lose access to the console, but a restart of the HyperTerminal session with a new Baud rate of 115200 will fix this! | ||
| + | |||
| + | 7. At the '''switch:''' prompt, begin the xmodem transfer of the new IOS image: | ||
| + | |||
| + | switch: '''copy xmodem: flash:''imagefilename''''' | ||
| + | Begin the Xmodem or Xmodem-1K transfer now... | ||
| + | CCC | ||
Revision as of 04:58, 7 March 2011
This is a bit of nastiness! You have a switch that refuses to boot. When you watch what's happening on the console you see errors like this:
Error loading "flash:c3750-k9-mz.122-44.se2.bin" Interrupt within 5 seconds to abort boot process. Boot process failed... switch:
You have a corrupt IOS image! To recover you will need Microsoft Windows HyperTerminal to perform an xmodem transfer of a new IOS image to the switch (obviously you can use other terminal emulators etc, but you'll get no help from me :-). This method has been tested with a Cisco 3750G. You can see more specific info for different switch models here.
1. Connect to the switch with HyperTerminal with these the settings:
Baud: 9600 Data bits: 8 Parity: None Stop bits: 1 Flow control: None
2. If the switch is not already at the switch: prompt, remove the power cord. Hold down the MODE button on the front of the switch and re-insert the power cord. Wait until the SYST light is flashing away and let go of the MODE button.
3. You should be at the switch: prompt. Type the following commands:
switch: flash_init switch: load_helper
4. List the contents of the switches flash memory
switch: dir flash: Directory of flash:/ 2 -rwx 10761792 <date> c3750-k9-mz.122-44.se2.bin 3 -rwx 676 <date> vlan.dat 4 -rwx 7807 <date> config.backup 83 -rwx 98 <date> private-config.text 86 -rwx 1048 <date> multiple-fs 5113856 bytes available (10885120 bytes used)
5. If there is no room in flash for another IOS image, delete the old one:
switch: delete flash:c3750-k9-mz.122-44.se2.bin Are you sure you want to delete "flash:c3750-k9-mz.122-44.se2.bin" (y/n)?y File "flash:c3750-k9-mz.122-44.se2.bin" deleted
6. To speed the xmodem transfer up, change the Baud rate of the switch
switch: set BAUD 115200
You will lose access to the console, but a restart of the HyperTerminal session with a new Baud rate of 115200 will fix this!
7. At the switch: prompt, begin the xmodem transfer of the new IOS image:
switch: copy xmodem: flash:imagefilename Begin the Xmodem or Xmodem-1K transfer now... CCC
