Erasing Startupconfig via ROMMON: Catalyst 6500-E

[TULLYMCFARLAND]

Hello,

First time posting on this forum. 

I am having difficulty erasing the startup config on a Catalyst 6500-E switch. 

I'm able to get into ROMMON via ctrl-break sequence, but once there I'm at a loss for what to do. I tried changing confreg to 0x2142, no good. 

I tried running the ctrl-break sequence after the "*Jun 2 14:47:11.443: %OIR-SP-6-CONSOLE: Changing console ownership to route processor" prompt, doesn't enter ROMMON at all. 

Additional details below: 

System Bootstrap, Version 12.2(17r)SX7, RELEASE SOFTWARE (fc1)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 2009 by cisco Systems, Inc.
Cat6k-Sup720/RP platform with 1048576 Kbytes of main memory

Cisco IOS Software, s72033_sp Software (s72033_sp-ADVIPSERVICESK9-M), Version 15.1(2)SY12, RELEASE SOFTWARE (fc4)

cisco WS-C6509-E (R7000) processor (revision 1.5) with 983008K/65536K bytes of memory.
Processor board ID SMG1420N00Q
SR71000 CPU at 600Mhz, Implementation 0x504, Rev 1.2, 512KB L2 Cache

A solution is appreciated, the goal is to wipe both startup config and the vlan.dat file. 

[marce1000]

  - @TULLYMCFARLAND    >.... I tried changing confreg to 0x2142, no good. 
                                                     Why didn't that work ?

   M.

[TULLYMCFARLAND]

Looks like I was in SP and not RP. Got it sorted. Thank you!

[David Ruess]

Hello,

Please see document below for possible solution to your issue.

https://www.cisco.com/c/en/us/support/docs/lan-switching/vlan/217969-reset-catalyst-switches-to-factory-defau.html

-David

[Jens Albrecht · Accepted solution]

Hello @TULLYMCFARLAND,

the key is to send the ctrl-break sequence immediately after the message '%OIR-SP-6-CONSOLE: Changing console ownership to route processor'.

If you wait just a bit too long, it does not work and you have to retry again.

If you press ctrl-break before this message, then you get into rommon mode of the switch processor. You can set the confreg register there as well but it will not do anything. It must be set in rommon mode of the route processor.

Once you set the confreg for the RP and rebooted the device ignoring the startup-config, then you can delete the config and vlan.dat files. You cannot do this in rommon mode directly because the filesystem is read-only in rommon.

There is a detailed step-by-step guide from Cisco that you can find here:

http://www.cisco.com/en/US/products/hw/switches/ps700/products_password_recovery09186a0080133fb1.shtml#topic1

HTH!

[TULLYMCFARLAND]

I'll try waiting for the routing processor prompt again and post an update as soon as possible.

[TULLYMCFARLAND]

Alright it worked, I waited until 2-3 seconds after the prompt for RP and it worked, thank you!

[TULLYMCFARLAND]

One more question, do you have to manually re-enter RP ROMMON and change the confreg 0x2142 to a different value or does it clear the confreg value automatically upon running the "enable >> copy run start" commands? 

[marce1000]

  - @TULLYMCFARLAND    You always have to change confreg  manually 

  M.

[Jens Albrecht]

A simple "copy run start" does not change the config-register but there is no need to re-enter rommon mode again to change it back.

You can use the command "config-register 0x2102" in global config mode to switch back to normal behavior.

Verification can be done with the "show version" command which will list the current value of the config-register which is probably 0x2142 and the new value after next reboot.

HTH!