Sep 172017
 

First step is connecting the Cisco console to our workstation. I chose to use the Console cable plugged into a Prolific Serial-to-USB adapter. While you can plug your adapter into your Windows workstation and connect via Putty I do not recommend it. Even at Windows 7 I have issues with the adapter and I’m not using one of those cheap Chinese knockoffs. Without fail my workstation will eventually BSoD. Lenovo work laptop or Acer personal laptop it doesn’t matter. I prefer to connect to my Ubuntu workstation and use minicom.

Plug in your adapter and check “dmesg” to identify your serial device (usually /dev/ttyUSB0).


$ dmesg |tail
[   88.483038] usb 1-3: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[   88.483050] usb 1-3: Product: USB-Serial Controller
[   88.483053] usb 1-3: Manufacturer: Prolific Technology Inc.
[   89.517987] usbcore: registered new interface driver usbserial
[   89.518001] usbcore: registered new interface driver usbserial_generic
[   89.518012] usbserial: USB Serial support registered for generic
[   89.520965] usbcore: registered new interface driver pl2303
[   89.520998] usbserial: USB Serial support registered for pl2303
[   89.521033] pl2303 1-3:1.0: pl2303 converter detected
[   89.521962] usb 1-3: pl2303 converter now attached to ttyUSB0

The connection details are as follows:

  • 9600 baud
  • 8 data bits
  • 2 stop bits
  • No parity
  • None (flow control)

$sudo minicom –s
configuration -> Serial port setup
A -> /dev/ttyUSB0 -> Enter
E -> C -> X -> Enter
F -> Enter
configuration -> Exit -> Enter

Press the “Mode” button and power on your device. After a few seconds release the button. You will see the following once the device boots.

Boot Sector Filesystem (bs) installed, fsid: 2
Base ethernet MAC Address: 00:22:be:1b:8c:00
Xmodem file system is available.
The password-recovery mechanism is enabled.

The system has been interrupted prior to initializing the
flash filesystem.  The following commands will initialize
the flash filesystem, and finish loading the operating
system software:

    flash_init
    boot

switch: flash_init
Initializing Flash...
flashfs[0]: 5 files, 1 directories
flashfs[0]: 0 orphaned files, 0 orphaned directories
flashfs[0]: Total bytes: 32514048
flashfs[0]: Bytes used: 11672064
flashfs[0]: Bytes available: 20841984
flashfs[0]: flashfs fsck took 10 seconds.
...done Initializing Flash.

switch: dir flash:
Directory of flash:/

    2  -rwx  1919      <date>               private-config.text
    3  -rwx  11660773  <date>               c2960-lanbasek9-mz.122-58.SE2.bin
    4  -rwx  1140      <date>               vlan.dat
    5  -rwx  3096      <date>               multiple-fs
    6  -rwx  2816      <date>               config.text

20841984 bytes available (11672064 bytes used)

switch: del flash:config.text
Are you sure you want to delete "flash:config.text" (y/n)?y
File "flash:config.text" deleted

switch: del flash:vlan.dat
Are you sure you want to delete "flash:vlan.dat" (y/n)?y
File "flash:vlan.dat" deleted

switch: boot
Loading "flash:/c2960-lanbasek9-mz.122-58.SE2.bin"...@@@@@@@@@@@@@@@@@@@@@@@@@@@
File "flash:/c2960-lanbasek9-mz.122-58.SE2.bin" uncompressed and installed, ent0
executing...

              Restricted Rights Legend

Use, duplication, or disclosure by the Government is
subject to restrictions as set forth in subparagraph
(c) of the Commercial Computer Software - Restricted
Rights clause at FAR sec. 52.227-19 and subparagraph
(c) (1) (ii) of the Rights in Technical Data and Computer
Software clause at DFARS sec. 252.227-7013.

           cisco Systems, Inc.
           170 West Tasman Drive
           San Jose, California 95134-1706

Cisco IOS Software, C2960 Software (C2960-LANBASEK9-M), Version 12.2(58)SE2, RE)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2011 by Cisco Systems, Inc.
Compiled Thu 21-Jul-11 02:13 by prod_rel_team

Initializing flashfs...

. . . SNIP . . .

         --- System Configuration Dialog ---

Enable secret warning
----------------------------------
In order to access the device manager, an enable secret is required
If you enter the initial configuration dialog, you will be prompted for the enat
If you choose not to enter the intial configuration dialog, or if you exit setu,
please set an enable secret using the following CLI in configuration mode-
enable secret 0 <cleartext password>
----------------------------------
Would you like to enter the initial configuration dialog? [yes/no]:no

Now you have a clean slate to work with.
 
Resources
https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst2960/hardware/installation/guide/2960_hg/hgcliset.html
https://fatmin.com/2012/12/02/how-to-reset-cisco-catalyst-2960-back-to-factory-defaults/comment-page-1/

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