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Cisco C6880-X Configs will not be removed

CliveAllen
Level 1
Level 1

Hi,

I have received some C6880-X Switches that are used. Rather stupidly, the previous owners have left the configurations on them. I have managed to change the config register to get around the enable password but, for some reason, the Configuration files are being stubborn and will not erase. So I have tried the following commands:

erase startup, erase nvram, write erase - Then I reload the device after it informaing me that all files in nvram have been removed and that there is no startup config. I say no to anything being saved. After the device reloads the config is miraculously back again.

I have also tried changing the register and erasing (0x2142 and then back to 0x2102). Nothing seems to be getting rid of the configuration. So I cannot reset to factory defaults.

Anyone got any other ideas to try and rectify this?

1 Accepted Solution

Accepted Solutions

I have read this bug but I have never, actually, seen this bug "in action" until now. 
Yes, the VLAN database is "sticky" and the switch's config is default. 
the only way to get rid of the sticky VLAN is to manually remove them "no vlan <number>" and reboot the switch. 
Do not forget to delete the VTP details as well.

View solution in original post

15 Replies 15

Leo Laohoo
Hall of Fame
Hall of Fame

 

delete /f /r nvram:startup-config
delete /f /r const_nvram:vlan.dat
delete /f /r system:running-config
wr erase

 

Hi Leo,

Unfortuanatly this has not worked either. However, there was one difference I see to the commands you have listed:

There is no "system" available after the "delete /f /r" command, but there was "bootdisk" so I just completed that as the third command with "running-config".

When reloaded and I type "show run" the full previous config is still there.

As an add on, I do not know if this switch may have been a part of a VSS. It looks like it was and was wondering if this was the second/backup would it only accept commands from a primary? (It is currently not connected to anything other than console)

Show us the running config after the reboot. 

Here is the output:

Router#dir ?
/all List all files
/recursive List files recursively
all-filesystems List files on all filesystems
bootdisk: Directory or file name
cns: Directory or file name
const_nvram: Directory or file name
image: Directory or file name
ivfs: Directory or file name
microcode: Directory or file name
null: Directory or file name
nvram: Directory or file name
system: Directory or file name
tar: Directory or file name
tmpsys: Directory or file name
| Output modifiers

Router#delete /f /r system:running-config
                             ^
% Invalid input detected at '^' marker.

Router#dir system:
Directory of system:/

2 -r-- 0 <no date> default-running-config
3 drwx 0 <no date> image
21 dr-x 0 <no date> memory
1 -rw- 6871 <no date> running-config
20 dr-x 0 <no date> vfiles

No space information available

Router#cd system:
Router#dir
Directory of system:/

2 -r-- 0 <no date> default-running-config
3 drwx 0 <no date> image
21 dr-x 0 <no date> memory
1 -rw- 6871 <no date> running-config
20 dr-x 0 <no date> vfiles


Router#delete running-config
                      ^
% Invalid input detected at '^' marker.

 

I wonder if this "config" you are trying to get rid of is the default config of the switch.  Hence, I want to see the entire "sh run" (or sh start) config.

Hi Leo,

Apologies for the delay in response. I am not in the office again until Tuesday 26th July 2022 and have no remote access to the switches. I can get the sh run output for you tomorrow but I can tell you the following:

There are VLANs, Route Maps and Access Lists in the config so I am pretty certain that this is not the default

Please provide the "sh boot" output.

Hi Leo,

Apologies. I am currently stuck looking at a multicast issue. I will get this info to you as soon as I can. Many thanks for your patience.

Hi Leo,

Apologies for the delay. I believe some of the config is actually a default config as I also see it on the live systems. Would be good if you could confirm though please. I have attached the config (please note that I expect the VLANs are not part of a default but the copp and access lists may well be).

I have read this bug but I have never, actually, seen this bug "in action" until now. 
Yes, the VLAN database is "sticky" and the switch's config is default. 
the only way to get rid of the sticky VLAN is to manually remove them "no vlan <number>" and reboot the switch. 
Do not forget to delete the VTP details as well.

Hello,

when you issue the 'dir:' command, you will see several file systems. Access all of them and check if the config is in there, if so, delete the respective file...

As per my response to Leo, I can see "system" when I complete the "dir ?" but when I try and complete, for example "delete system:" the IOS tells me it is an unrecognised command. If use "delete nvram:" (just to see if it recognises nvram, not actually delete it) then it sees it okay.

I cannot, no matter what command I use, access the "system" directory. And this is my problem. I can remove the other files, as per leos recommendation, just not the running-config. I even changed the location to the "system" directory and tried to delete it and it would not recognise the commands.

@leo - The config that is on there is just class-maps to access-lists but that will interfere with the new configuration. Let me see if I can get the details and post here (the output of the commands)

Let me explain a little more after some investigation. I have now found that this switch was never part of a VSS so that theory is no good.

When I complete "dir ?" the directory "system" is there. When I complete "dir system" then "running-config" is in there. The problem appears to be that I cannot access the system directory and therefore cannt remove the running-config - which now looks like it is persistant.

To prove the peristant state of the running-config I manually removed all of the present configuration with the "no" commands. Completed a "show run" to ensure the config was gone (it was). I then completed a "write" to the startup config. I then completed a reload. During the reload the system stated it found a startup config and then proceeeded to load. When I typed in "show run" the old running-confrig was back again. I just cannot get rid of it unless I can get into the "system" dir to manually remove it as per your suggestion.