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Catalyst 2950 and Catalyst 2955 Switch Software Configuration Guide
OL-10101-02
Chapter 31 Troubleshooting
Using Recovery Procedures
Recovering from a Software Failure
Switch software can be corrupted during an upgrade, by downloading the wrong file to the switch, and
by deleting the image file. In all of these cases, the switch does not pass the power-on self-test (POST),
and there is no connectivity.
This procedure uses the Xmodem Protocol to recover from a corrupt or wrong image file. There are many
software packages that support the Xmodem Protocol, and this procedure is largely dependent on the
emulation software that you are using.
Follow these steps to recover from a software failure:
Step 1 Connect a PC with terminal-emulation software supporting the Xmodem Protocol to the switch console
port.
Step 2 Set the line speed on the emulation software to 9600 baud.
Step 3 Disconnect the switch power cord.
Step 4 Reconnect the power cord to the switch.
The software image does not load. The switch starts in boot loader mode, which is indicated by the
switch# prompt.
Step 5 Use the boot loader to enter commands, and start the transfer.
switch# copy xmodem: flash:image_filename.bin
Step 6 When the Xmodem request appears, use the appropriate command on the terminal-emulation software
to start the transfer and to copy the software image to flash memory.
Recovering from Lost or Forgotten Passwords on Non-LRE Catalyst 2950 Switches
Follow these steps if you have forgotten or lost the switch password on a non-LRE Catalyst 2950 switch:
Step 1 Connect a terminal or PC with terminal emulation software to the consoleservice port. For more
information, see the switch hardware installation guide.
Note You can configure your switch for Telnet by following the procedure in the “Accessing the CLI”
section on page 2-9.
Step 2 Set the line speed on the emulation software to 9600 baud.
Step 3 Unplug the switch power cord.
Step 4 Reconnect the power cord to the switch and, within 15 seconds, press the Mode button while the System
LED above port 1X is still flashing green. Continue pressing the Mode button until the System LED
turns briefly amber and then solid green; then release the Mode button.
Several lines of information about the software appear, as do instructions:
The system has been interrupted prior to initializing the flash file system. These
commands will initialize the flash file system, and finish loading the operating system
software: