Factory reset Catalyst 3500 XL
- Connect PC with terminal emulation software to console port via serial cable (9600 baud, 8 bits, no parity)
- Press the "Mode" button at the front of the switch and connect the power, keep pressing for 2 more seconds after the LED above 1X port goes off, then release the "Mode" button.
- You should see few lines of information at your PC TE saying about: System has been interrupted ...
- At the "switch:" prompt issue the "flash_init" command, you should see the information about Initializing Flash ...
- Wait untill "switch:" prompt, then issue the command "load_helper".
- You should get "switch:" prompt immediately. Issue the command: "dir flash:"
- You shoul see files "config.text" and vlan.dat" in your flash, you need to delete these.
- Issue the command "delete flash:config.text" and after the warning Are you sure ... confirm by "y".
- Issue the command "delete flash:vlan.dat" and after the warning Are you sure ... confirm by "y".
- Issue the command "boot", the switch should load IOS with factory default (ie. no configuration file, no vlan database).
credits...HERE