Cisco CATALYST3750

  1. Start the console session.

    Plug in serial cable to console port of device from PC COM1 port
    Open PuTTY and select "Serial" connection type, leave baud rate (Speed) and other settings as default.

  2. Access the pre-boot switch command line interface.

    Press and hold down the Mode button.
    Cisco CATALYST3750
    Plug power into device and if a power button exists, turn it on.
    Xmodem file system is available. The password-recovery mechanism is enabled. Initializing Flash...
    After 15+ seconds release the Mode button.
    flashfs[0]: filesystem check interrupted! ...done Initializing Flash. Boot Sector Filesystem (bs) installed, fsid: 3 The system has been interrupted, or encountered an error during initializion of the flash filesystem. The following commands will initialize the flash filesystem, and finish loading the operating system software: flash_init load_helper boot
    You should be presented with the switch:  prompt.

  3. Initialise Flash and list existing files.

    Type the flash_init command:
    switch: flash_init Initializing Flash... flashfs[0]: 501 files, 7 directories flashfs[0]: 0 orphaned files, 0 orphaned directories flashfs[0]: Total bytes: 32514048 flashfs[0]: Bytes used: 9646080 flashfs[0]: Bytes available: 22867968 flashfs[0]: flashfs fsck took 7 seconds. ...done Initializing Flash. Setting console baud rate to 9600...
    Type the dir flash: command:
    switch: dir flash: Directory of flash:/ 2 -rwx 856 <date> vlan.dat 3 -rwx 5 <date> private-config.text 5 -rwx 16552 <date> config.text 7 drwx 192 <date> c3750-ipbase-mz.122-35.SE5 22867968 bytes available (9646080 bytes used)
    In the above example, c3750-ipbase-mz.122-35.SE5 is a directory containing the OS image so is not to be deleted.

  4. Delete configuration files and reboot.

    Use the del command on all data-bearing files, confirming each with y:
    switch: del flash:vlan.dat Are you sure you want to delete "flash:vlan.dat" (y/n)?y File "flash:vlan.dat" deleted switch: del flash:private-config.text Are you sure you want to delete "flash:private-config.text" (y/n)?y File "flash:private-config.text" deleted switch: del flash:config.text Are you sure you want to delete "flash:config.text" (y/n)?y File "flash:config.text" deleted
    Type the boot command:
    switch: boot
    Further output should take you to a prompt to terminate autoinstall, respond with y
    00:01:31: %SYS-5-RESTART: System restarted -- Cisco IOS Software, C3750 Software (C3750-IPBASE-M), Version 12.2(35)SE5, RELEASE SOFTWARE (fc1) Copyright (c) 1986-2007 by Cisco Systems, Inc. Compiled Thu 19-Jul-07 19:15 by nachen Would you like to terminate autoinstall? [yes]: y

  5. Check settings are either gone or reset to factory defaults.

    Type n when prompted to enter the initial configuration dialog:
    --- System Configuration Dialog --- Would you like to enter the initial configuration dialog? [yes/no]: n
    Type the enable command for elevated privileges:
    Switch>enable
    Type the erase startup-config command and confirm with y then type the show vlan command:
    Switch#erase startup-config Erasing the nvram filesystem will remove all configuration files! Continue? [confirm]y[OK] Erase of nvram: complete Switch#show vlan VLAN Name Status Ports ---- -------------------------------- --------- ------------------------------- 1 default active Gi4/0/1, Gi4/0/2, Gi4/0/3 Gi4/0/4, Gi4/0/5, Gi4/0/6 Gi4/0/7, Gi4/0/8, Gi4/0/9 Gi4/0/10, Gi4/0/11, Gi4/0/12 Gi4/0/13, Gi4/0/14, Gi4/0/15 Gi4/0/16, Gi4/0/17, Gi4/0/18 Gi4/0/19, Gi4/0/20, Gi4/0/21 Gi4/0/22, Gi4/0/23, Gi4/0/24 Gi4/0/25, Gi4/0/26, Gi4/0/27 Gi4/0/28 1002 fddi-default act/unsup 1003 token-ring-default act/unsup 1004 fddinet-default act/unsup 1005 trnet-default act/unsup VLAN Type SAID MTU Parent RingNo BridgeNo Stp BrdgMode Trans1 Trans2 ---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------ 1 enet 100001 1500 - - - - - 0 0 1002 fddi 101002 1500 - - - - - 0 0 1003 tr 101003 1500 - - - - - 0 0 VLAN Type SAID MTU Parent RingNo BridgeNo Stp BrdgMode Trans1 Trans2 ---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------ 1004 fdnet 101004 1500 - - - ieee - 0 0 1005 trnet 101005 1500 - - - ibm - 0 0 Remote SPAN VLANs ------------------------------------------------------------------------------ Primary Secondary Type Ports ------- --------- ----------------- ------------------------------------------

  6. Copy all the output from the session into your records.

    Right-click PuTTY's titlebar, from that dropdown menu click on "Copy All to Clipboard"
    Open the file of record certifying the deconfiguration of this device and use CTRL V to paste all the output from PuTTY into that file. Formatting the text with a fixed-width font helps it look more readable.

  7. End the session.

    Close PuTTy.